72dpi to 300dpi

RA
Posted By
Red Ant
May 25, 2004
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6277
Replies
141
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Closed
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?

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T
tacitr
May 25, 2004
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?

Yes. Use the Image Size command and turn "Resample Image" OFF.

"Resample" means "change the number of pixels." If resampling is turned off, the pixel dimensions will be identical–a 1200×1600 pixel image will still be 1200×1600 pixels. The resolution will change, and the size of the picture when it is printed out will change.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
GP
Gene Palmiter
May 25, 2004
the photo has 1200 x 1600 pixels…it has no dots per inch until you tell it how many inches it will be. Often your viewer/editor will default to some DPI…but that is illusory. It means nothing. Change the number under image size and no resampling and the numbers change…but the file will not.

"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

TD
The Doormouse
May 25, 2004
"Red Ant" wrote:

Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?

Yes, this is very basic.
You should be able to do this with no problem.

The Doormouse


The Doormouse cannot be reached by e-mail without her permission.
RA
Red Ant
May 25, 2004
"Tacit" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?

Yes. Use the Image Size command and turn "Resample Image" OFF.
"Resample" means "change the number of pixels." If resampling is turned
off,
the pixel dimensions will be identical–a 1200×1600 pixel image will still
be
1200×1600 pixels. The resolution will change, and the size of the picture
when
it is printed out will change.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html

If i want the pixel dimensions and the document size to be remained but only the dpi change to 300dpi, can i do it this way:
1) turn of the resample and change the dpi to 300, then
2) turn on the resample and set the document size back to its original. Does that cause any lose in pix quality?
D
Don
May 25, 2004
Image>Image size, then uncheck "resample image" and change resolution to 300, click "OK." But I wouldn’t consider that an "upgrade" since the picture will still be 1200×1600.

Don

"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

XT
xalinai_Two
May 25, 2004
On Wed, 26 May 2004 01:10:50 +0800, "Red Ant" wrote:

"Tacit" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?

Yes. Use the Image Size command and turn "Resample Image" OFF.
"Resample" means "change the number of pixels." If resampling is turned
off,
the pixel dimensions will be identical–a 1200×1600 pixel image will still
be
1200×1600 pixels. The resolution will change, and the size of the picture
when
it is printed out will change.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html

If i want the pixel dimensions and the document size to be remained but only the dpi change to 300dpi, can i do it this way:
1) turn of the resample and change the dpi to 300, then
2) turn on the resample and set the document size back to its original. Does that cause any lose in pix quality?

No. That causes loss of mathematics.

DPI is dots per inch, or with regard to computer images pixels per inch.

So the formula is as follows:

pixels divided by inches is DPI

So when you increase the DPI with the number of pixels constant your document size will shrink. And when you increase dpi with the document size constant the number of pixels will increase too.

Michael
T
tacitr
May 25, 2004
If i want the pixel dimensions and the document size to be remained but only
the dpi change to 300dpi, can i do it this way:

You say you want the pixel dimensions to stay the same. Then you say you want the document size to stay the same. That is impossible.

If you resample the image, the document size will stay the same, but the pixel dimension will change.

If you turn off resampling, the pixel dimensions will stay the same, but the document size will change.

I am not clear on what you are asking. However, resampling an image ALWAYS degrades its quality. Always. You can not invent image detail that does not exist in the original; it is impossible to resample an image to increase its resolution and have the result be as good as if you had simply made the image at the proper size and resolution to begin with.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
WA
Wilder and Wilder
May 25, 2004
The most reliable way to interpolate an image up to a higher resolution is by using proprietory software like Genuine Fractals. Another method which works well is to use ‘stair interpolation’. Basically this uses bicubic resizing in Photoshop in 10% increments until the size is reached. Either way, expect some degradation of the image. How much depends on how good the original is.

W&W
—————————-
"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

J
JJS
May 25, 2004
"Not for Publication" wrote in message

The most reliable way to interpolate an image up to a higher resolution is by using proprietory software like Genuine Fractals. […]

Booo.
J
jaSPAMc
May 25, 2004
On Wed, 26 May 2004 00:24:11 +0800, "Red Ant" found these unused words floating about:

Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px X 1600px, 300dpi?
F1 => "image size"
J
jaSPAMc
May 25, 2004
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker setting doesn’t require interpolation!

On Wed, 26 May 2004 07:01:59 +1000, "Not for Publication" found these unused words floating about:

The most reliable way to interpolate an image up to a higher resolution is by using proprietory software like Genuine Fractals. Another method which works well is to use ‘stair interpolation’. Basically this uses bicubic resizing in Photoshop in 10% increments until the size is reached. Either way, expect some degradation of the image. How much depends on how good the original is.

W&W
—————————-
"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?
D
Don
May 25, 2004
Oops – I didn’t read it right – sorry.

Don

"Don" wrote in message
Image>Image size, then uncheck "resample image" and change resolution to 300, click "OK." But I wouldn’t consider that an "upgrade" since the picture will still be 1200×1600.

Don

"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

J
jenelisepasceci
May 26, 2004
(Tacit) wrote:


I am not clear on what you are asking. However, resampling an image ALWAYS degrades its quality. Always. You can not invent image detail that does not exist in the original; it is impossible to resample an image to increase its resolution and have the result be as good as if you had simply made the image at the proper size and resolution to begin with.

You’ve repeated your mantra quite often since I read this group, and in principle you are right, _but_ it is also true that information stored in an image beyond the resolution of the eye of the beholder is wasted. Upsampling is allright IMO, if the target image is looked at from a reasonably greater distance than the original.
Negatives are routinely "resampled" to considerably larger size when a fine print is made. There is definitely a loss of total information in this process but at the same time there is a gain in useful information, since image detail is revealed to the naked eye which was invisible beforehand. From your notion, anything except a contact sheet would be degradation, but this is evidently not the case. I am convinced that you are well aware of this, I just wanted to make clear to the novice that there is a relation between target resolution and viewing distance. Normally, there is no good reason to create a life-size poster of a truck at a resolution of 1200 lpi 😉

Peter
WA
Wilder and Wilder
May 26, 2004
Bugger off jerk.
Unless of course your vocabulary improves past one syllable. Then you ought to get a life too.

"jjs" wrote in message
"Not for Publication" wrote in message

The most reliable way to interpolate an image up to a higher resolution
is
by using proprietory software like Genuine Fractals. […]

Booo.

WA
Wilder and Wilder
May 26, 2004
DO you ever read the garbage you post?

"J. A. Mc." wrote in message
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker
setting
doesn’t require interpolation!

B
Brian
May 26, 2004
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker
setting doesn’t require interpolation!

DO you ever read the garbage you post?

And why is that garbage? It’s utterly true…

The ONLY thing that matters in measuring the resolution of a digital image is the pixel dimensions; PPI (inaccurately referred to in this thread as DPI) is merely an abstract based on the pixel dimensions applied to a particular output size, and does not have any direct correlation to the resolution of a given image. A 1500px X 1500px image contains the exact same number of pixels (and therefore the same resolution) whether it’s being printed at 300ppi or 72ppi.
J
john
May 26, 2004
In article , wrote:

(Tacit) wrote:
[…]

You’ve repeated your mantra quite often since I read this group, and in principle you are right, _but_ it is also true that information stored in an image beyond the resolution of the eye of the beholder is wasted. Upsampling is allright IMO, if the target image is looked at from a reasonably greater distance than the original.

See the tomes on Viewing Distance. The nominal standard ‘reading’ viewing distance is 10". But what you posit is only partly true. When photographers refer to viewing distance they speak to
line-pairs-per-millimeter and when they enlarge very often the information is really there to enlarge, but it is less ‘sharp’ with greater enlargements. Viewing distance in that regard concerns the accutance of the human eye/brain. When we interpolate a lower resolution image, we do not have the information to enlarge. It’s a whole different thing.

Of course, most people have lower standards and interpolation is just fine. It largely depends upon upon the requisites of the individual or the client.
J
john
May 26, 2004
In article <HIZsc.11765$>, "Wilder and
Wilder" wrote:

Bugger off jerk.
Unless of course your vocabulary improves past one syllable. Then you ought to get a life too.

Hook, line and sinker. Oh, and killfile.
S
Stuart
May 26, 2004
Brian wrote:
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker
setting doesn’t require interpolation!

DO you ever read the garbage you post?

And why is that garbage? It’s utterly true…

The ONLY thing that matters in measuring the resolution of a digital image is the pixel dimensions; PPI (inaccurately referred to in this thread as DPI) is merely an abstract based on the pixel dimensions applied to a particular output size, and does not have any direct correlation to the resolution of a given image. A 1500px X 1500px image contains the exact same number of pixels (and therefore the same resolution) whether it’s being printed at 300ppi or 72ppi.

It takes a while for some people to understand that concept and all they need to do is think about it logically.

Stuart
T
tacitr
May 26, 2004
Negatives are routinely "resampled" to considerably larger size when a fine print is made. There is definitely a loss of total information in this process but at the same time there is a gain in useful information, since image detail is revealed to the naked eye which was invisible beforehand.

A negative is llimited in resolution, of course, by the physical size of the silver halide crystals in it–yet a negative, even a 35MM negative, contains significantly more information than a 72ppi image that’s 1200 pixels wide.

Furthermore, a negative is a continuoust-tone object that is not divided into discrete pixels in the same way as a scanned image.

Enlarging a negative to make a print does not "resample" it. Enlarging a negative is loosely analagous to enlarging a scanned image without resampling; the total number of discrete image elements (pixels or silver grains) remains the same, they’re simply made larger. Enlarging a negative is better compared to using Image Size to take a 24-mm image at 2,000 pixels per inch and making it a 240-mm image at 200 pixels per inch.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
RA
Red Ant
May 26, 2004
"J. A. Mc." wrote in message
On Wed, 26 May 2004 00:24:11 +0800, "Red Ant" found these unused words floating about:

Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?
F1 => "image size"

I really appreciate you guys for the valuable opinions.

My objective to this is simple. I have a client with this 1200px X 1600px, 72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot per inch could improve the clarity of the picture…..
T
tacitr
May 26, 2004
My objective to this is simple. I have a client with this 1200px X 1600px, 72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot per inch could improve the clarity of the picture…..

Nothing–absolutely nothing, no technique or program–can increase the clarity of the picture, because nothing can invent image detail that isn’t there.

Sounds like your client needs to re-create the image. Sorry… —
Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
WA
Wilder and Wilder
May 26, 2004
The problem with narrow minded people is they think the world revolves around their ideas. The day you can define a pixel as an element of linear measurement, will be the day I start printing them.

Until then, the only process of measuring an image for printing is in dots or lines. To print a 1200×1600 72 dpi image at 300 dpi requires the image to be interpolated up to that size. Are all Pommies idiots or only the ones posting to graphic news groups?

Wilder on the waves.
—————————–

"Stuart" wrote in message
Brian wrote:
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker
setting doesn’t require interpolation!

DO you ever read the garbage you post?

And why is that garbage? It’s utterly true…

The ONLY thing that matters in measuring the resolution of a digital image is the pixel dimensions; PPI (inaccurately referred to in this thread as DPI) is merely an abstract based on the pixel dimensions applied to a particular output size, and does not have any direct correlation to the resolution of a given image. A 1500px X 1500px image contains the exact same number of pixels (and therefore the same resolution) whether it’s being printed at 300ppi or 72ppi.

It takes a while for some people to understand that concept and all they need to do is think about it logically.

Stuart
B
Brian
May 26, 2004
To print a 1200×1600 72 dpi image at 300 dpi requires the image to be interpolated up to that size.

That’s not true at all – if you print a 1200 x 1600 image at 72ppi the image will measure 16.667" x 22.223"; print the exact same image at 300ppi and it will be 4" x 5.334".

Pixel dimensions and PPI are not intertwined, but completely unrelated measurements. There is no such thing as a 1200 x 1600 72ppi image. There is a 1200 x 1600 image, of course, but the ppi is wholly dependent on what size you print that 1200 x 1600 image.
J
john
May 27, 2004
In article <40b4c546$>, "Red Ant" wrote:

I really appreciate you guys for the valuable opinions.

In turn, I appreciate your candor.

My objective to this is simple. I have a client with this 1200px X 1600px, 72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot per inch could improve the clarity of the picture…..

As you will learn, the software cannot invent detail. However, remind your client of the concept of viewing distance. If the image is large, then persons looking at it from a distance will, at least, see it as if it were just a smaller print closer up. (for the most part). If they move closer, they should simply not expect to see more detail.
J
john
May 27, 2004
In article , "Not for Publication"
wrote:

The problem with narrow minded people is they think the world revolves around their ideas. […]

And that rather well describes your stuck-state. Welcome to the ‘fuckwit’ section of my killfile.
M
Mike
May 27, 2004
In article <
135.docsis.hbci.com>, says…
In article <40b4c546$>, "Red Ant" wrote:
I really appreciate you guys for the valuable opinions.

In turn, I appreciate your candor.

My objective to this is simple. I have a client with this 1200px X 1600px, 72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot per inch could improve the clarity of the picture…..

As you will learn, the software cannot invent detail. However, remind your client of the concept of viewing distance. If the image is large, then persons looking at it from a distance will, at least, see it as if it were just a smaller print closer up. (for the most part). If they move closer, they should simply not expect to see more detail.
And for some such applications (for example – producing a large poster from a relatively low resolution image), it might then be appropriate to interpolate to higher
resolution followed by filtering so the closer-than-
optimal observer wil see a blurred or grained effect
rather than block-like pixels.
S
Stephan
May 27, 2004
"Red Ant" wrote in message
"J. A. Mc." wrote in message
On Wed, 26 May 2004 00:24:11 +0800, "Red Ant" found
these
unused words floating about:

Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to
1200px
X
1600px, 300dpi?
F1 => "image size"

I really appreciate you guys for the valuable opinions.

My objective to this is simple. I have a client with this 1200px X
1600px,
72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot
per
inch could improve the clarity of the picture…..

Simply put: You should not have clients before you know what you are doing.

Stephan
S
Stuart
May 27, 2004
Not for Publication wrote:
The problem with narrow minded people is they think the world revolves around their ideas. The day you can define a pixel as an element of linear measurement, will be the day I start printing them.

Until then, the only process of measuring an image for printing is in dots or lines. To print a 1200×1600 72 dpi image at 300 dpi requires the image to be interpolated up to that size. Are all Pommies idiots or only the ones posting to graphic news groups?

Wilder on the waves.
—————————–

Your point is only relevant to the final print output size.

Stuart
WA
Wilder and Wilder
May 27, 2004
So tell me then. When is a photograph not a photograph?
For a photograph to exist at all it has to occupy space, be a physical object. If it is not, it cannot be a photograph but merely a digital file.

To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those dimensions occupy as a photograph in any quality at all, it must be interpolated up to 300 dpi or thereabouts or printed at a size considerably smaller than those dimensions describe.

What you lot are attempting to make out is that this image of 1200×1600 at 72 dpi has in fact no dimension which is wrong because the use of a dpi qualifier after the pixel size of the image, creates a set of dimensions as a precursor to becoming a photograph.

If the OP had said a 22"x16" image at 72 dpi instead of quoting the pixel count and specifying a dpi, those feeble minds unable to grasp the concept that a photograph is a measurable object might open their minds to reality and start to comprehend that a photograph cannot exist until it is produced. A digital file is only a means of producing the photograph, it is not the photograph itself.
—————————————————-

"Stuart" wrote in message
Not for Publication wrote:
The problem with narrow minded people is they think the world revolves around their ideas. The day you can define a pixel as an element of
linear
measurement, will be the day I start printing them.

Until then, the only process of measuring an image for printing is in
dots
or lines. To print a 1200×1600 72 dpi image at 300 dpi requires the
image to
be interpolated up to that size. Are all Pommies idiots or only the ones posting to graphic news groups?

Wilder on the waves.
—————————–

Your point is only relevant to the final print output size.
Stuart
XT
xalinai_Two
May 27, 2004
On Thu, 27 May 2004 19:45:10 +1000, "Not for Publication" wrote:

So tell me then. When is a photograph not a photograph?
For a photograph to exist at all it has to occupy space, be a physical object. If it is not, it cannot be a photograph but merely a digital file.
To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those dimensions occupy as a photograph in any quality at all, it must be interpolated up to 300 dpi or thereabouts or printed at a size considerably smaller than those dimensions describe.

You still don’t get it.

A digital image of 1200×1600 pixels has no such thing as 72dpi. It has a number of pixels. DPI is not a property of the digital image but of the printed one. Size in inches is not a property of the digital image but of the printed one.

A image of 1200x1600pixels IS PRINTED AT 72 ppi if you print it 16.67 inches x 22.22 inches.

If you talk about printing in photo quality, you talk about printing images at 200 to 300ppi.

Now printing 16.67 inches x 22.22 inches in photo quality requires something between 3333×4444 and 5000x6666pixels.

You can not print a 1600x1200pixel/72dpi image at 300dpi.

When you print 1600x1200pixels at 300dpi you have a 5.3×4" 300dpi print.
When you print it at 16.67×22.22 inches, you have a 72dpi print. You can have it either 72dpi or 300dpi.

You either have a digital image that only has pixels or you have a paper image that can have inches, dpi and pixels (if it was digital before) and even dots if you are discussing printer specialties.

And if you upsample the poor 1600×1200 to 6400x4800pixels and print it to 22.22×16.67 inches you have a 288dpi print that contains 1/16th or
6.25percent original data and 93.75 percent unsharp inventions of some
kind of software.

What you lot are attempting to make out is that this image of 1200×1600 at 72 dpi has in fact no dimension which is wrong because the use of a dpi qualifier after the pixel size of the image, creates a set of dimensions as a precursor to becoming a photograph.

The DPI stored in the image is just useless for sizing.

When you use an image you decide what quality (print resolution) you need – then you apply that value (or range of values) to the available image’s pixel size to check their possible print sizes. If you rely on any real world sizes resulting from different resolutions stored in the images you are lost.

So either you have the DPI setting in all your images set to one and the same value to eliminate on the fly calculations or you ignore them and calculate real world sizes according to your project specs.

DPI values in images have only one use and that is when Xdpi and Ydpi are different – images having non square pixels that need to be adapted before further processing.

If the OP had said a 22"x16" image at 72 dpi instead of quoting the pixel count and specifying a dpi, those feeble minds unable to grasp the concept that a photograph is a measurable object might open their minds to reality and start to comprehend that a photograph cannot exist until it is produced. A digital file is only a means of producing the photograph, it is not the photograph itself.

A photograph is a real world object that is measured in real world units – inches, centimetres, whatever. When it is scanned, the digital image exists in the digital world and is measured in pixels only as you don’t know the size it will have when it is returned into the real world. Any DPI value stored with the image can only refer to the past if it comes from the scanning process or be completely arbitrary in the case of a digital camera. Digital cameras don’t know the size of what they capture, even if they could and should leave the DPI field empty.

Michael
B
Brian
May 27, 2004
Simply put: You should not have clients before you know what you are doing.

Now *there’s* the smartest thing I’ve read in this thread yet! 8^)
B
Brian
May 27, 2004
To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those dimensions occupy as a photograph in any quality at all, it must be interpolated up to 300 dpi or thereabouts or printed at a size considerably smaller than those dimensions describe.

Those dimensions you’re supplying don’t describe *anything*, that’s the part you fail to see – there is NO SUCH THING as a 1200 x 1600 72ppi image. There is ONLY a 1200 x 1600 image; the pixels per inch measurement ONLY comes into play when you actually print the image, and is variable depending on the dimensions at which the image is printed.

What you lot are attempting to make out is that this image of 1200×1600 at 72 dpi has in fact no dimension which is wrong because the use of a dpi qualifier after the pixel size of the image, creates a set of dimensions as a precursor to becoming a photograph.

Nope, it’s absolutely correct. A digital image has only its pixel dimensions to measure its resolution; again, pixels per inch is an abstract derived from dividing the pixel dimensions by the output size. This number is in no way inherent to the image at all.

A 1200 x 1600 image printed at 72ppi, and the same image printed at 300ppi, have EXACTLY THE SAME RESOLUTION, specifically 1200 X 1600. As I posted previously, printing this image at 72ppi will result in a print size of 16.667" x 22.223"; printing the same image at 300ppi will result in a print size of 4" x 5.334".

To look at it another way, printing an image at 16.667" x 22.223" at 300ppi would require an image resolution of 5000px X 6666.9px, which is CLEARLY A DIFFERENT IMAGE RESOLUTION than 1200 x 1600. It’s simple math.

You didn’t understand a single word of which I and the others wrote, but yet you continue to post as if you somehow have this knowledge that tens of thousands of qualified professionals somehow lack. Disturbing, that…
J
john
May 27, 2004
In article , "Not for Publication"
wrote:

So tell me then. When is a photograph not a photograph?
For a photograph to exist at all it has to occupy space, be a physical object. If it is not, it cannot be a photograph but merely a digital file.

Duh.

To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those dimensions occupy as a photograph in any quality at all, it must be interpolated up to 300 dpi or thereabouts or printed at a size considerably smaller than those dimensions describe.

Let’s make this simple. A printer that does, say, 360ppi will make a small print of a 1200x1600ppi image. To make a larger print and keep the same detail, a digital image containing a larger number of pixels is neccessary. Agreed?

The argument is that a person wanting detail in a print will need more pixels in the very first generation of the image. If he does not have those pixels, then interpolation is neccessary.

Underneath all this is the fact that more pixels (created in a manner other than interpolation) in that first generation image is better than interpolation after the fact.

Are we okay now?
T
tacitr
May 27, 2004
You can not print a 1600x1200pixel/72dpi image at 300dpi.

Yes, you can; the resulting print is 5.33 by 4 inches in dimension.

A digital image does have a resolution. This resolution, measured in pixels per inch, is stored as part of the file, usually in the file’s header. The resolution makes no difference until the image is printed; nevertheless, it is still a property of the file, and Photoshop will show it as such.

A raster-based image is described by four properties: its pixel resolution, which is the number of pixels it contains; its physical size on output; its resolution in pixels per inch; and the number of bits per pixel. The first three are all related.

Each pixel is a square of color. Each pixel is assigned a physical size; this size is not relevant to display of an image on screen, but is relevant to outpit. A 300 pixel per inch image is made of squares called "pixels," each one of which is 1/300th of an inch wide. A 72 pixel per inch image is made of squares called "pixels," each one of which is 1/72 of an inch wide.

Let us suppose you have a file 1,000 pixels wide.

If your file is 100 pixels per inch, then your file will print 10 inches wide.

If your file is 200 pixels per inch, then your file will print 5 inches wide.

If your file is 1,000 pixels per inch, then it will print 1 inch wide.

In all three cases, your file is exactly the same on a computer screen; the only thing different is how big the pixels are in print.

Think about a tile mosaic for a second–because that is exactly what your picture is. It’s a tile mosaic. Every tile is a pixel.

You’re an artist, and you make a tile mosaic that is 100 tiles wide and 100 tiles deep. If each tile you used is one foot wide, your mosaic is 100 feet wide and 100 feet tall. If each tile you used is one inch wide, your mosaic is 100 inches wide and 100 inches tall. If each tile is 1/2" wide, your mosaic is 50 inches wide and 50 inches tall.

The "resolution" of a picture is very simple: It is nothing but how big each pixel is!

So what is "resampling"?

Let’s say you have a tile mosaic and you made it out of tiles one inch wide. Your mosaic is 100 inches wide and 100 inches tall.

Let’s say you re-create your mosaic with tiles 1/2" wide.

You have two choices:

You can re-create your tile mosaic with the same number of tiles. Now your mosaic is smaller, because the tiles are smaller. Your new mosaic is 50 inches wide and 50 inches tall.

Or, you can re-create your mosaic at the same physical size–100 by 100 inches. Now you have to use more tiles–four times as many tiles, in fact. Your new mosaic is 200 tiles wide and 200 tiles high. This is "resampling." Changing the number of tiles–that is, changing the number of pixels.

If you resample, your image will print at the same size. But because you have to create new pixels out of thin air, the quality of the picture goes in the toilet. There is no way to invent new pixels out of nothing; the computer must "guess" what color to make those pixels, and you will never see detail that was not in the original picture to start with.

If you do not resample, the image will print at a different size.

But that’s all there is to it. To figure out how big a digital image will print, you take the total number of pixels, and you divide that number by the size of each pixel, and that will tell you how big the print will be. If your image is 1,000 pixels wide, and each pixel is one inch wide, your image is at one pixel per inch and will be 1,000 inches wide when you print it.


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B
Brian
May 27, 2004
You can not print a 1600x1200pixel/72dpi image at 300dpi.

Yes, you can; the resulting print is 5.33 by 4 inches in dimension.

I think where he is getting terminally confused is by using both the pixel dimensions and the PPI to describe the resolution of the image; the image in question is 1600×1200, period, not 1600×1200 72ppi.

But then again you and I and several others have already clearly explained this multiple times, so perhaps his confusion transcends to other levels…
LP
Larry Preuss
May 27, 2004
in article , Xalinai at
wrote on 5/27/04 7:27 AM:

The DPI stored in the image is just useless for sizing.

Would it makes things more clear if you did not use the term "dpi" imprecisely. My understanding is that dpi refers to a capability of the printer, depending largely on the architecture of its print head. If the terms spi, ppi and dpi were used according to their strict definition, rather than loosely as they mst often are, there would be fewer misunderstandings.
LP
XT
xalinai_Two
May 27, 2004
On 27 May 2004 14:36:20 GMT, (Tacit) wrote:

You can not print a 1600x1200pixel/72dpi image at 300dpi.

Yes, you can; the resulting print is 5.33 by 4 inches in dimension.

No. The printed image has a size and you can determine pixels per inch using a ruler and your knowledge about the number of pixels. If you can’t apply the ruler to the image the units on the ruler have no meaning to the image.

A digital image does have a resolution. This resolution, measured in pixels

Up to here I agree…

per
inch, is stored as part of the file, usually in the file’s header. The resolution makes no difference until the image is printed; nevertheless, it is still a property of the file, and Photoshop will show it as such.

….here not.

We both know it is irrelevant until the image is printed and it stays irrelevant whether Photoshop or the pope in Rome shows it.

A raster-based image is described by four properties: its pixel resolution, which is the number of pixels it contains; its physical size on output; its resolution in pixels per inch; and the number of bits per pixel. The first three are all related.

A raster based image is described by its height and width in pixels, its depth in bits per pixel and in very few cases in its pixels apect ratio via Xdpi and Ydpi if both are different where pixels are not square.

Each pixel is a square of color. Each pixel is assigned a physical size; this size is not relevant to display of an image on screen, but is relevant to outpit. A 300 pixel per inch image is made of squares called "pixels," each one of which is 1/300th of an inch wide. A 72 pixel per inch image is made of squares called "pixels," each one of which is 1/72 of an inch wide.

Each pixel is a rectangle of color with a default of square pixels for current non moving images. Pixels in video applications are not square, neither in PAL nor in NTSC formats.

Let us suppose you have a file 1,000 pixels wide.

If your file is 100 pixels per inch, then your file will print 10 inches wide. If your file is 200 pixels per inch, then your file will print 5 inches wide. If your file is 1,000 pixels per inch, then it will print 1 inch wide.
In all three cases, your file is exactly the same on a computer screen; the only thing different is how big the pixels are in print.

Right. This proves that there is no valid dpi or pixel size specification for the digital image inside the computer. The dpi free digital image is converted using a printing device in three paper images having the same number of pixels but a different number of pixels per inch. The process of printing to a certain device at a specified size creates the PPI value.

Terminology is important:
You can print any raster image at any arbitrary ppi value. But you can not print any raster image at a ppi value that is different from the one you calculate from output size and number of pixels – the PPI make sense for the printed (=real world) object only.

Think about a tile mosaic for a second–because that is exactly what your picture is. It’s a tile mosaic. Every tile is a pixel.

You’re an artist, and you make a tile mosaic that is 100 tiles wide and 100 tiles deep. If each tile you used is one foot wide, your mosaic is 100 feet wide and 100 feet tall. If each tile you used is one inch wide, your mosaic is 100 inches wide and 100 inches tall. If each tile is 1/2" wide, your mosaic is 50 inches wide and 50 inches tall.

The "resolution" of a picture is very simple: It is nothing but how big each pixel is!

You are perfectly right: Because the tile is a real world object that can be measured. The pixel raster has no size, as your example shows. It is only the plan for the arrangement of the tiles. The one who designes the raster image does not need to know how big the tiles are – the one who lays the tiles either calculates the necessary tile size for a given room (print size given, pixel number given, PPI varies) or he lays the image with tiles of a given size (PPI specified, pixel number is given, size varies) filling an area of a size that results from the number of tiles and their size.

So what is "resampling"?

Let’s say you have a tile mosaic and you made it out of tiles one inch wide. Your mosaic is 100 inches wide and 100 inches tall.

Let’s say you re-create your mosaic with tiles 1/2" wide.
You have two choices:

You can re-create your tile mosaic with the same number of tiles. Now your mosaic is smaller, because the tiles are smaller. Your new mosaic is 50 inches wide and 50 inches tall.
This isn’t resampling. This is changing the desired print resolution.

Or, you can re-create your mosaic at the same physical size–100 by 100 inches. Now you have to use more tiles–four times as many tiles, in fact. Your new mosaic is 200 tiles wide and 200 tiles high. This is "resampling." Changing the number of tiles–that is, changing the number of pixels.
If you resample, your image will print at the same size. But because you have to create new pixels out of thin air, the quality of the picture goes in the toilet. There is no way to invent new pixels out of nothing; the computer must "guess" what color to make those pixels, and you will never see detail that was not in the original picture to start with.

The tradesman would do a pixel resize and simply lay four tiles instead of one, the artisan would adjust edges.

And that is what you should do when you don’t have image data for a large format: slightly blur the image, upsample, blur a bit more against aliasing and add some noise to simulate crispness.

If you do not resample, the image will print at a different size.

But that’s all there is to it. To figure out how big a digital image will print, you take the total number of pixels, and you divide that number by the size of each pixel, and that will tell you how big the print will be. If your image is 1,000 pixels wide, and each pixel is one inch wide, your image is at one pixel per inch and will be 1,000 inches wide when you print it.

To figure out how big a digital image will print divide the number of pixels and dividy by your desired print resolution. Or divide the number of pixels by the corresponding length and check whether the result is within a range you can accept or not. But here you need some feeling/experience for what can be accepted…

But again, you are right: this isn’t wizardry, it is only a little bit of math (3rd grade, I think).
And our discussion about the sense of DPI in the average, square pixeled computer image is as useless^h^h^h^hful as the data field itself 🙂

Michael
XT
xalinai_Two
May 27, 2004
On Thu, 27 May 2004 09:03:25 -0500, (jjs)
wrote:

In article , "Not for Publication"
wrote:

So tell me then. When is a photograph not a photograph?
For a photograph to exist at all it has to occupy space, be a physical object. If it is not, it cannot be a photograph but merely a digital file.

Duh.

To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those dimensions occupy as a photograph in any quality at all, it must be interpolated up to 300 dpi or thereabouts or printed at a size considerably smaller than those dimensions describe.

Let’s make this simple. A printer that does, say, 360ppi will make a small print of a 1200x1600ppi image. To make a larger print and keep the same detail, a digital image containing a larger number of pixels is neccessary. Agreed?

The argument is that a person wanting detail in a print will need more pixels in the very first generation of the image. If he does not have those pixels, then interpolation is neccessary.

Underneath all this is the fact that more pixels (created in a manner other than interpolation) in that first generation image is better than interpolation after the fact.

Are we okay now?

Isn’t that a bit too pragmatic?

We have such a fine discussion about the number of angels on a needle tip and you call us back to earth. 🙂

Michael

PS: Et ceterum censeo… There is no inch size for rater images.
WA
Wilder and Wilder
May 27, 2004
You are quite wrong Brian…
To describe an image in both pixels and dpi is to define a pre-dimensioned print size of a photograph or other physical printed page. To define an image in pixels alone is to describe only a digital file. We are talking here in a PHOTOshop group so for the purpose of comprehension, it can be freely assumed discussions are about photographs, altering or editing them and printing photographs.

No one on this earth has ever been able to hold and view a digital image in the way a photograph is held and viewed. Why? Because a digital image of ## x ## pixels has no size of dimension, only of presence. It can exist only in magnetic space or in an electrified tube, not the atmosphere and therefore all who argue that specifying 2 components of measurement (pixels and dots per inch) is irrelevant are unable to understand the difference between a photograph and a magnetically created file. Unfortunately, Brian… You are one such person.

Adobe has for as long as I can recall, specified 2 measurements in their image file descriptions. I suggest that as Adobe invented Postscript which is now the standard page description language of the printing industry, their use of describing an image in both pixels and dots per inch is also a valid method of measuring a "ready for print" image and providing in that description, a means of readily assessing the quality of the printed page.

Wherever people get the idea that pixels are all that count is quite irrelevant to what the printing industry and photographic industry use in their descriptions or for that matter, need in order to print a page. What is relevant is that some people (you included) have such an unshakable belief that the world is flat as to continue on with an argument which has no merit.

Probably a better group for you to post to would be a digital artists group where pixels wear red hats and the dpi arrest them for exposure. Your opinions are just as fanciful when it comes to printing photographs… This is after all a group devoted to software used for photographic manipulation. —————————————-

"Brian" wrote in message
To print a 1200 x1600, 72 dpi image at the 22"x16" (approx) those
dimensions
occupy as a photograph in any quality at all, it must be interpolated up
to
300 dpi or thereabouts or printed at a size considerably smaller than
those
dimensions describe.

Those dimensions you’re supplying don’t describe *anything*, that’s the part you fail to see – there is NO SUCH THING as a 1200 x 1600 72ppi image. There is ONLY a 1200 x 1600 image; the pixels per inch measurement ONLY comes into play when you actually print the image, and is variable depending on the dimensions at which the image is printed.

What you lot are attempting to make out is that this image of 1200×1600
at
72 dpi has in fact no dimension which is wrong because the use of a dpi qualifier after the pixel size of the image, creates a set of dimensions
as
a precursor to becoming a photograph.

Nope, it’s absolutely correct. A digital image has only its pixel dimensions to measure its resolution; again, pixels per inch is an abstract derived from dividing the pixel dimensions by the output size. This number is in no way inherent to the image at all.

A 1200 x 1600 image printed at 72ppi, and the same image printed at 300ppi, have EXACTLY THE SAME RESOLUTION, specifically 1200 X 1600. As I posted previously, printing this image at 72ppi will result in a print size of 16.667" x 22.223"; printing the same image at 300ppi will result in a print size of 4" x 5.334".

To look at it another way, printing an image at 16.667" x 22.223" at 300ppi would require an image resolution of 5000px X 6666.9px, which is CLEARLY A DIFFERENT IMAGE RESOLUTION than 1200 x 1600. It’s simple math.

You didn’t understand a single word of which I and the others wrote, but yet you continue to post as if you somehow have this knowledge that tens of thousands of qualified professionals somehow lack. Disturbing, that…
B
Brian
May 27, 2004
You are quite wrong Brian…

No, I’m not. I’ve been working professionally in prepress for (too many!) years now, I know exactly what I am talking about. Perhaps you misread my posts, because what you are saying is not technically wrong but it addresses issues that I am not speaking of…

To describe an image in both pixels and dpi is to define a pre-dimensioned print size of a photograph or other physical printed page. To define an image in pixels alone is to describe only a digital file.

Which is *all* I am doing here. The resolution of a digital image is defined *only* by its pixel dimensions. The pixel per inch measurement is *only* valid when speaking of print output.

Again (for what seems like the hundredth time) if you print a 1200×1600 image at 72ppi the output will be 16.667" x 22.223"; if you print the same image at 300ppi the print output will be 4" x 5.334". In both cases, however, the resolution of the digital image is *exactly* the same, specifically 1200px X 1600px. The print output has two different resolutions, one @ 72ppi and the other @ 300, but I am *not* referring to that for this particular discussion.

Photoshop provides a ppi reference as a courtesy only; if you change the ppi of any image with resample unchecked you are only affecting the display of the print dimensions of the image; the resolution has *not* been affected by even one single pixel.

Read thoroughly and you will see that where we disagree is not on the technical aspects of the disucssion, but rather the topic we are each speaking about.

And lastly, stop being so condescending. You act as if you are the only person here who has a clue what Photoshop is for and can do, or what photography or print is, and in that sir you are woefully mistaken.
J
JJS
May 27, 2004
"Not for Publication" wrote in message
[…] We are talking
here in a PHOTOshop group so for the purpose of comprehension, it can be freely assumed discussions are about photographs, altering or editing them and printing photographs.

Is it too much to ask a PS user to understand what a pixel really is? It is elementary to the whole digital paradigm! If a PS user can spend huge money to buy the product, then they are likely to be have the skills necessary to balance their checkbook, and that’s all the magic they need to know in order to render pixels into a print without incurring dissapointments from being willfully ignorant.

No one on this earth has ever been able to hold and view a digital image
in
the way a photograph is held and viewed. Why? Because a digital image of
##
x ## pixels has no size of dimension, only of presence.

Utter pseudo-philosophical hogwash. A red herring. Following your mental recursion (eg: leapfrogging through your own metaphysical asshole) leads nowhere but to more of the same, but elementary, proven metrics of pixels always yields perfectly correct answers through simple grade-school arithmetic.

By your reconing so far, you would have sent people into lala land to solve their printing issue. Have you not already told them that they should print a small image to a much larger format by interpolating? We were trying very hard to make it perfectly clear that when they do that, PS has to invent data to create the image. That is important. You used the term interpolation correctly (albeit perhaps by accident) and you cry that we are being too technical?

Put a plug in it, NFP.
V
Voivod
May 27, 2004
On Fri, 28 May 2004 07:03:40 +1000, "Not for Publication" scribbled:

This is after all a group devoted to software used for photographic manipulation.

That’s not a decision you get to make for others.
S
sunlei6662003
May 28, 2004
Download AlbumFamiy software at http://www.albumsfamily.com to help you
With its Image Browser, you can manage your images as easily as you can imagine; its Image Viewer shows your images in the most advanced Virtual Album; the PhotoEdit and Photofun functions give you wide room to adjust your images and make all kinds of prints such as postcards, cards, stationery and so on; what’s more, the Bundled Functions allow you to scan images and send images to your specified destination just by a single click. With AlbumFamily, You can establish the most beautiful albums for yourself, your family and your friends, you can produce your own style stationery on your desk. You will never find another application software which fits you so well and satisfy you so much!
WA
Wilder and Wilder
May 28, 2004
Aparently those who would offer themselves as keepers of the (flawed) "pixels rule" school, failed to read or comprehend the original post and instead set off on a tangent to expound their idea of how flat the world really is until someone else highlighted the point that the OP wanted to print the picture… And isn’t that what I’ve been discussing all along?

"Brian" wrote in message
Simply put: You should not have clients before you know what you are
doing.
Now *there’s* the smartest thing I’ve read in this thread yet! 8^)
XT
xalinai_Two
May 28, 2004
On Thu, 27 May 2004 14:56:36 -0400, Larry Preuss
wrote:

in article , Xalinai at
wrote on 5/27/04 7:27 AM:

The DPI stored in the image is just useless for sizing.

Would it makes things more clear if you did not use the term "dpi" imprecisely. My understanding is that dpi refers to a capability of the printer, depending largely on the architecture of its print head. If the terms spi, ppi and dpi were used according to their strict definition, rather than loosely as they mst often are, there would be fewer misunderstandings.

The relevant property for a digital image is the amount of information in the image. This is specified by two dimensions of pixel count and one dimension of bit depth. As long as you stay in the digital universe there is no further property that can add information about the amount of detail available in the image.

Print resolution or sizes that compare the image to objects outside the digital universe are only valid in this real world. During the image’s stay in digital space they are like the information on a can of paint that says it will last for five square meters – they make assumptions how someone will use it and specify a sample outcome of its application. But saying "I have a 1000x2000pixel/72dpi image" is like saying "I have a 800 millilitres 5 square meter can of paint!"

Michael
XT
xalinai_Two
May 28, 2004
On Fri, 28 May 2004 07:03:40 +1000, "Not for Publication" wrote:

You are quite wrong Brian…
To describe an image in both pixels and dpi is to define a pre-dimensioned print size of a photograph or other physical printed page. To define an image in pixels alone is to describe only a digital file. We are talking here in a PHOTOshop group so for the purpose of comprehension, it can be freely assumed discussions are about photographs, altering or editing them and printing photographs.

Adobe has for as long as I can recall, specified 2 measurements in their image file descriptions. I suggest that as Adobe invented Postscript which is now the standard page description language of the printing industry, their use of describing an image in both pixels and dots per inch is also a valid method of measuring a "ready for print" image and providing in that description, a means of readily assessing the quality of the printed page.

You are talking of the habits in an industry. The use of a term in an industry may be widespread but still either wrong or just jargon.

To combine possible output resolution and the data volume of an image in a specification leads to misunderstandings like two people discussing the difference between a 72dpi and a 300dpi version of the same 2000×3000 pixel digital image.

What those people not understand is that they should discuss the difference between a 72dpi 8"x10" and a 300dpi 8"x10" image – real world objects that actually do have a resolution measured in dpi.

Wherever people get the idea that pixels are all that count is quite irrelevant to what the printing industry and photographic industry use in their descriptions or for that matter, need in order to print a page. What is relevant is that some people (you included) have such an unshakable belief that the world is flat as to continue on with an argument which has no merit.

An industry where you give someone an image of 6000x4000pixels that has a stored dpi of 72 to be printed 20 inches wide and get the image rejected because "the resoluton is too low, we need it in 300dpi" should very quickly re-learn their job.

Michael
LP
Larry Preuss
May 28, 2004
in article , Xalinai at
wrote on 5/28/04 8:20 AM:

On Thu, 27 May 2004 14:56:36 -0400, Larry Preuss
wrote:

in article , Xalinai at
wrote on 5/27/04 7:27 AM:

The DPI stored in the image is just useless for sizing.

Would it makes things more clear if you did not use the term "dpi" imprecisely. My understanding is that dpi refers to a capability of the printer, depending largely on the architecture of its print head. If the terms spi, ppi and dpi were used according to their strict definition, rather than loosely as they mst often are, there would be fewer misunderstandings.

The relevant property for a digital image is the amount of information in the image. This is specified by two dimensions of pixel count and one dimension of bit depth. As long as you stay in the digital universe there is no further property that can add information about the amount of detail available in the image.

Print resolution or sizes that compare the image to objects outside the digital universe are only valid in this real world. During the image’s stay in digital space they are like the information on a can of paint that says it will last for five square meters – they make assumptions how someone will use it and specify a sample outcome of its application. But saying "I have a 1000x2000pixel/72dpi image" is like saying "I have a 800 millilitres 5 square meter can of paint!"
Michael

Not "dpi." Dots per inch is a measure of how many dots of ink a printer is able to place in a measured space, is limited by the design of the print head and your decision of standard, fine print, or whatever the notation is for your printer, and has no relationship to the measurements of what is presented to it to print.
Larry
V
Voivod
May 28, 2004
On Fri, 28 May 2004 11:45:06 GMT, "Wilder and Wilder" scribbled:

Aparently those who would offer themselves as keepers of the (flawed) "pixels rule" school, failed to read or comprehend the original post and instead set off on a tangent to expound their idea of how flat the world really is until someone else highlighted the point that the OP wanted to print the picture… And isn’t that what I’ve been discussing all along?

The funniest part is you STILL think you’re right….
S
Stuart
May 28, 2004
Larry Preuss wrote:

Not "dpi." Dots per inch is a measure of how many dots of ink a printer is able to place in a measured space, is limited by the design of the print head and your decision of standard, fine print, or whatever the notation is for your printer, and has no relationship to the measurements of what is presented to it to print.
Larry

If you had vaguely followed this thread then you would not have written your post.

Stuart
J
jaSPAMc
May 28, 2004
On Thu, 27 May 2004 06:53:11 +1000, "Not for Publication" found these unused words floating about:

The problem with narrow minded people is they think the world revolves around their ideas.
This would be a self-description?

The day you can define a pixel as an element of linear
measurement, will be the day I start printing them.
Got plenty of ink/toner and paper?

A pixel can easily be defined as having a linear measurement when referenced by dpi. THAT’s the whole point of having the dpi MARKER in the file. That it can be altered, that’s a function of modern technology.

pixel = 1/dpi in inches

Until then, the only process of measuring an image for printing is in dots or lines. To print a 1200×1600 72 dpi image at 300 dpi requires the image to be interpolated up to that size.

Are all Pommies idiots or only the ones
posting to graphic news groups?
Self application … again? <G>

IMHO You need to learn the physical facts AND read before dumping. Double check the OP’s exact query … again!

Wilder on the waves.
—————————–

"Stuart" wrote in message
Brian wrote:
d’Oh! 1200×1600 to 1200×1600 with a different ‘printer’ dpi marker
setting doesn’t require interpolation!

DO you ever read the garbage you post?

And why is that garbage? It’s utterly true…

The ONLY thing that matters in measuring the resolution of a digital image is the pixel dimensions; PPI (inaccurately referred to in this thread as DPI) is merely an abstract based on the pixel dimensions applied to a particular output size, and does not have any direct correlation to the resolution of a given image. A 1500px X 1500px image contains the exact same number of pixels (and therefore the same resolution) whether it’s being printed at 300ppi or 72ppi.

It takes a while for some people to understand that concept and all they need to do is think about it logically.

Stuart
S
Stuart
May 28, 2004
Voivod wrote:

The funniest part is you STILL think you’re right….

LOL!!
J
jaSPAMc
May 28, 2004
On Thu, 27 May 2004 00:26:42 +0800, "Red Ant" found these unused words floating about:

"J. A. Mc." wrote in message
On Wed, 26 May 2004 00:24:11 +0800, "Red Ant" found these unused words floating about:

Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?
F1 => "image size"

I really appreciate you guys for the valuable opinions.

My objective to this is simple. I have a client with this 1200px X 1600px, 72dpi picture requires to blow to an A2 size poster. My knowledge is limited, I thought by remaining the document size but increasing the dot per inch could improve the clarity of the picture…..
There’s the rub … IF you’re simply (as stated) altering the dpi and retaining the pixels as before, then the printed image will be smaller.

To keep the -printed- size the same, then you’ll have to increase the pixels. It’s a classic inter-related triangle. To change one part, something else has to change.

NFP’s misreading of your exact words actually gave the most likely solution – albeit expensive for a small occasional use.

One trick you might try is to use "image size" and resample at 600 dpi. Then apply the median filter (noise category) and then resample down to 300 dpi.

You can try the "unsharpen mask" at this point, but with just a subtle change needed.

In many cases it produces a pleasing and usable image. In either way you have not any more real information, just presented differently.
LP
Larry Preuss
May 28, 2004
in article c97nuc$r11$
wrote on 5/28/04 12:01 PM:

Larry Preuss wrote:

Not "dpi." Dots per inch is a measure of how many dots of ink a printer is able to place in a measured space, is limited by the design of the print head and your decision of standard, fine print, or whatever the notation is for your printer, and has no relationship to the measurements of what is presented to it to print.
Larry

If you had vaguely followed this thread then you would not have written your post.

Stuart
I have been following it, with some interest.
S
Stephan
May 28, 2004
wrote in message
Download AlbumFamiy software at http://www.albumsfamily.com to help you…

Why would anyone want to spend money on such crap?
Windows comes with about the same image editing power with Imaging.

Stephan
J
jaSPAMc
May 28, 2004
On Fri, 28 May 2004 14:28:06 -0400, Larry Preuss
found these unused words floating about:

in article c97nuc$r11$
wrote on 5/28/04 12:01 PM:

Larry Preuss wrote:

Not "dpi." Dots per inch is a measure of how many dots of ink a printer is able to place in a measured space, is limited by the design of the print head and your decision of standard, fine print, or whatever the notation is for your printer, and has no relationship to the measurements of what is presented to it to print.
Larry

If you had vaguely followed this thread then you would not have written your post.

Stuart
I have been following it, with some interest.

The "dpi" used by most graphics programs isn’t "printer dots". Truly it should be called "ppi" but getting manufacturers to understand is like getting ‘resolution’ straight for newbies.
A7
aka 717
May 28, 2004
"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

I think you want to keep the picture the same size,
whatever that is, and make in higher resolution.

It any case decide how big you want the picture,
enter that number in the crop tool along with dpi
that you desire and select the area that is best.
Be sure to have bicubic interpolation set in the
preferences.
J
john
May 29, 2004
In article <FaPtc.1621$>, "aka 717" wrote:

"Red Ant" wrote in message
Anyone knows how to upgrade a pix at 1200px X 1600px, 72dpi to 1200px
X
1600px, 300dpi?

I think you want to keep the picture the same size,
whatever that is, and make in higher resolution.

It any case decide how big you want the picture,
enter that number in the crop tool along with dpi
that you desire and select the area that is best.
Be sure to have bicubic interpolation set in the
preferences.

And so we come full circle, right back to the original nonsense we stared with . I hope someone got something valuable somewhere in this circle of confusion.
B
bhilton665
May 29, 2004
From: (jjs)

I hope someone got something valuable somewhere in this circle of confusion.

Circle of confusion? Don’t be so hyperfocal John!

🙂
WA
Wilder and Wilder
May 29, 2004
Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description. You only need to look at the current description of ‘fonts’ and their traditional description to see that.

Eventually the widespread use of including dpi in the measurement of an image’s size and quality will become the norm and traditionalists will forever morn the passing of yet another dead pixel.

"Xalinai" wrote in message
An industry where you give someone an image of 6000x4000pixels that has a stored dpi of 72 to be printed 20 inches wide and get the image rejected because "the resoluton is too low, we need it in 300dpi" should very quickly re-learn their job.

Michael
DH
David Haley
May 29, 2004
This day of Sat, 29 May 2004 06:04:19 GMT, "Wilder and Wilder" proclaimed:

Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description. You only need to look at the current description of ‘fonts’ and their traditional description to see that.

Eventually the widespread use of including dpi in the measurement of an image’s size and quality will become the norm and traditionalists will forever morn the passing of yet another dead pixel.

DPI is just like the scale on a map. If you make more world-km to the map-cm but don’t change how much world you’re representing, your map gets smaller. If you make less world-km to the map-cm but don’t change how much world you’re representing, your map gets bigger. It couldn’t be simpler. It’s not directly an issue of quality when you print, it’s an issue of scale: how many of those magic little computer bytes go into our dull little real-world inches. I appreciate your efforts in trying to bring us poor souls to modernity here, but I think I’ll pass on this particular "instruction" of yours. 🙂

-dhaley


~david-haley
WA
Wilder and Wilder
May 29, 2004
I certainly learned that many people vehemently believe their own opinions… Even if they differ from what others do in day to day use. Right at the start I said the only way the OP would achieve his aim was to interpolate the image up to 300 dpi before printing.

I think that started the fiasco where all the Pixels got arrested by the dpi and so the tale continues with no one giving an inch to anyone else… It was you, too John, who first started the row over printing the image and Booo’d me for suggesting it maybe possible if interpolated… Geezzzz!

"jjs" wrote in message
In article <FaPtc.1621$>, "aka 717" wrote:
And so we come full circle, right back to the original nonsense we stared with . I hope someone got something valuable somewhere in this circle of confusion.
J
john
May 29, 2004
In article <_XVtc.15963$>, "Wilder and
Wilder" wrote:

I certainly learned that many people vehemently believe their own opinions… Even if they differ from what others do in day to day use. Right at the start I said the only way the OP would achieve his aim was to interpolate the image up to 300 dpi before printing.

I think that started the fiasco where all the Pixels got arrested by the dpi and so the tale continues with no one giving an inch to anyone else… It was you, too John, who first started the row over printing the image and Booo’d me for suggesting it maybe possible if interpolated… Geezzzz!

The "Booo" was for your recommendation of Genuine Fractals, aka: Snake Oil.
V
Voivod
May 29, 2004
On Sat, 29 May 2004 06:04:19 GMT, "Wilder and Wilder" scribbled:

Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description.

Ladies and gentlemen – In this corner, wearing polka dots, weighing in at 98 lbs it’s the DPI Warrior! And in the other corner, weighing in at several gigatons it’s…. everyone else..
WA
Wilder and Wilder
May 29, 2004
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to surprising large dimensions and produce good to very good results… But then my python must surely be bigger than yours because of all the snake oil, eh?

"jjs" wrote in message
In article <_XVtc.15963$>, "Wilder and
Wilder" wrote:

I certainly learned that many people vehemently believe their own opinions… Even if they differ from what others do in day to day use.
Right
at the start I said the only way the OP would achieve his aim was to interpolate the image up to 300 dpi before printing.

I think that started the fiasco where all the Pixels got arrested by the
dpi
and so the tale continues with no one giving an inch to anyone else…
It
was you, too John, who first started the row over printing the image and Booo’d me for suggesting it maybe possible if interpolated… Geezzzz!

The "Booo" was for your recommendation of Genuine Fractals, aka: Snake
Oil.
T
tacitr
May 29, 2004
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to surprising large dimensions and produce good to very good results…

It produces "good to very good" results for people unskilled at digital imaging, or uncritical. I have used it, and even on their best-possible-case images, I personally find their results crap.

You know that breochure they produced, challenging you to pick the GF-interpolated image from the high-res image? I picked the interpolated image 12 out of 12 times.

Nothing–no technique, no algorithm, no program, nothing–can interpolate an image and produce image information which does not exist in the original.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
T
tacitr
May 29, 2004
Eventually the widespread use of including dpi in the measurement of an image’s size and quality will become the norm and traditionalists will forever morn the passing of yet another dead pixel.

True story: When i was working professional prepress at a trade shop called Dimension, we had a job order come in one day where the client had asked for a transparency to be scanned such that the scan would be 9 by 12 inches at 300 dpi.

Now, for the past thirty years, Dimension’s clients had been art directors and serious advertising professionals at big-name advertising agencies, so they never made that particular mistake. Lately, as more and more companies attempt (usually with dismal results) tosave money by bringing their advertising in-house, the experience and skill of Dimension’s client has dropped significantly.

Anyway, the job bag was passed to the scanner operator. This particular scanner operator, with 28 years’ experience running a drum scanner, was completely flummoxed; he had no idea what to do. He came to me and said "How can I make a scan at 300 dpi? That doesn’t make any sense! Do they want a prescreened halftone at 300 lines per inch? What the hell are they talking about?"

I laughed and explained, "Don’t sweat it, just make a 300 pixel per inch scan. The job’s for an ignoramous amateur who thinks "dpi" and "ppi" mean the same thing."

Sadly, five years later, the ignoramous amateurs seem to outnumber the skilled professionals even in the professional design and advertising industries.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
J
john
May 29, 2004
In article , "Not for Publication"
wrote:

I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to surprising large dimensions and produce good to very good results…

GF users raving positive impressions are a good determination of their uncritical skills, low expectations. Sometimes I wonder if today’s low expectations are not due to digital photography’s dilution of true quality imaging.
J
john
May 29, 2004
One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803

Rather daunting, isn’t it?
N
nomail
May 29, 2004
jjs wrote:

One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?

Daunting, yes. But written by someone who is clearly not as knowledgable as he thinks himsef. Just look at this quote: "today’s best cameras record digital files at a little more than 11 megapixels. But what if, in the near future, the standard moves up to 20 megapixels or higher? If you have backup on film, you can scan your images at a higher resolution."

That is nonsense. Yes, you can easily scan 20 Mpixel or more out of that piece of film. But if you record an 11 Mpixel file to film and scan it again, you will never get more detail than the original 11 Mpixel file contained. Your 20 Mpixel scan will be no different than interpolating the original 11 Mpixel file to 20 Mpixel. In fact, interpolation will almost certainly give better results, because output to film and scanning again will always cause some loss of detail, even if it’s done with the best equipment available. There is really no reason to backup on film, even apart from the fact that this would be incredibly expensive.


Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/
J
john
May 29, 2004
In article <1gek7co.1dgl06i1pkeugwN%>,
(Johan W. Elzenga) wrote:

jjs wrote:

One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?

Daunting, yes. But written by someone who is clearly not as knowledgable as he thinks himsef. Just look at this quote: "today’s best cameras record digital files at a little more than 11 megapixels. But what if, in the near future, the standard moves up to 20 megapixels or higher? If you have backup on film, you can scan your images at a higher resolution."
That is nonsense. Yes, you can easily scan 20 Mpixel or more out of that piece of film.

I believe there is a misunderstanding. The 11 megapixel was given as an example of the higher resolution prosumer cameras of the time. The author was saying "using today’s better digital camera, you will still fall short of Large Format film fidelity."

Clear?
V
Voivod
May 29, 2004
On Sat, 29 May 2004 10:45:48 -0500, (jjs)
scribbled:

One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?

Rather like crap really. It sounds like Arizona Highways magazine is composed of film snobs. How old is that article anyhow? "The best of the current generation of digital cameras records image files a little more than 11 megapixels." Kodak has a 14 MP camera out.
N
nomail
May 29, 2004
Voivod wrote:

On Sat, 29 May 2004 10:45:48 -0500, (jjs)
scribbled:

One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?

Rather like crap really. It sounds like Arizona Highways magazine is composed of film snobs. How old is that article anyhow? "The best of the current generation of digital cameras records image files a little more than 11 megapixels." Kodak has a 14 MP camera out.

And there are 20 Mpixels digital camera backs for medium and large format cameras. The problem is that people who are used to film, simply count pixels to compare film and digital. It is true that you can easily scan 25 Mpixels out of a 35mm slide, or 100 Mpixels out of a 6×7 cm slide. However, that does NOT mean that you need a 25 Mpixels digital camera to get the same quality as 35mm film, or 100 Mpixels digital camera to compete with 6×7 cm film. Direct comparison (in the British ‘Professional Photographer’ magazine for example) have shown that the Canon 1Ds (11 Mpixels) already beats an analog Canon 35mm camera with the same lens on it.


Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/
J
john
May 29, 2004
Voivod wrote:

Rather like crap really. It sounds like Arizona Highways magazine is composed of film snobs. How old is that article anyhow? "The best of the current generation of digital cameras records image files a little more than 11 megapixels." Kodak has a 14 MP camera out.

The difference between 11MP and 14MP is absolutely ZERO, and possibly MINUS. Why? because pixels don’t indicate quality in regards to how those pixels combined contribute to overall tone and color rendition, nor resolution.

If you live by the manufacturers’ metrics, you are already blinded.
V
Voivod
May 29, 2004
On Sat, 29 May 2004 17:21:27 -0500, (jjs)
scribbled:

Voivod wrote:

Rather like crap really. It sounds like Arizona Highways magazine is composed of film snobs. How old is that article anyhow? "The best of the current generation of digital cameras records image files a little more than 11 megapixels." Kodak has a 14 MP camera out.

The difference between 11MP and 14MP is absolutely ZERO, and possibly

No, it’s 3. 14 – 11 = 3 See, math works.

MINUS. Why? because pixels don’t indicate quality in regards to how those pixels combined contribute to overall tone and color rendition, nor resolution.

So because a POSSIBILITY exists that your $5000 14 MP digital SLR is of lower quality than your $8000 11MP camera that’s reason to say the difference is zero or even a ‘minus’?

If you live by the manufacturers’ metrics, you are already blinded.
T
tacitr
May 30, 2004
"The best of the
current generation of digital cameras records image files a little more than 11 megapixels." Kodak has a 14 MP camera out.

The difference in image quality between an 11 Mp camera and a 14 MP camera is negligable.

And it misses the point. Manufacurers love to blather about the number of pixels in a digital camera for the same reason scanner manufacturers love to blather about resolution: because most people are too ignorant to know that resolution is not the best measure of image quality, dynamic range is. (Of course, most people don’t even know what "dynamic range" means, so that’s to be expected.)

Dynamic range is the total amount of tonal range from light to dark that a device can represent. If a digital camera has a particular dynamc range, what that means in English is that anything brighter than the highest point of that tonal range will be pure white, and anything darker than the lowest point will be pure black.

Consumer and prosumer digital cameras tend to have a lower dynamic range than film. That means that while the film can still capture detail in the highlights and shadows, the digital image just shows white in the highlights and/or black in the shadows. (It’s the shadow end that’s typically most problematic for digital cameras.)

Consumer scanners have the same problem, which is why the pros make scans intended for publication on drum scanners, even though drum scanners can cost hundreds of times more than flatbed scanners.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
WA
Wilder and Wilder
May 30, 2004
Total crap.
National Geographic has been accepting images from Digital cameras for over a year. Now that is the definative publication for picture quality. Who the hell are Arizona Highways anyway? Christ… What is Arazona? Does anyone actually read the backwater magazine anyway?

"jjs" wrote in message
One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?
J
john
May 30, 2004
In article <nucuc.17432$>, "Wilder and
Wilder" wrote:

Total crap.
National Geographic has been accepting images from Digital cameras for over a year. Now that is the definative publication for picture quality. Who the hell are Arizona Highways anyway? Christ… What is Arazona? Does anyone actually read the backwater magazine anyway?

And your point is? NG has been accepting B&W forever, too. 🙂 Arizona Highways was referring to pictures it also uses for exhibitions, if that helps.

Oh, for a "backwater" magazine, it pays pretty well. Say what you like, it’s not all about pop culture afterall.
S
Stephan
May 30, 2004
"Not for Publication" wrote in message
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to surprising large dimensions and produce good to very good results… But then my
python
must surely be bigger than yours because of all the snake oil, eh?

Nobody would expect you to want to know you got ripped off. GF is not any better than Stair Interpolation and Stair interpolation can be replaced by a home made, free, action.

Stephan
S
Stephan
May 30, 2004
"jjs" wrote in message
In article <nucuc.17432$>, "Wilder and
Wilder" wrote:

Total crap.
National Geographic has been accepting images from Digital cameras for
over
a year. Now that is the definative publication for picture quality. Who
the
hell are Arizona Highways anyway? Christ… What is Arazona? Does anyone actually read the backwater magazine anyway?

And your point is? NG has been accepting B&W forever, too. 🙂 Arizona Highways was referring to pictures it also uses for exhibitions, if that helps.

No, there were talking about their out of this world quality, see here: "But an 11-megapixel capture is not nearly large enough for the sharp, high-resolution full-page reproductions we strive for on the printed pages of Arizona Highways magazine at 300 dots per inch"
My guess is that there are no stores offering digital cameras along Arizona’s highway’s yet or that Mr. Ensenberger is a Hasselblad or Leica user.

Stephan
N
nomail
May 30, 2004
Tacit wrote:

Consumer and prosumer digital cameras tend to have a lower dynamic range than film. That means that while the film can still capture detail in the highlights and shadows, the digital image just shows white in the highlights and/or black in the shadows. (It’s the shadow end that’s typically most problematic for digital cameras.)

That website is not talking about consumer of prosumer digital cameras. There are no consumer or prosumer cameras with 11 Mpixels.


Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/
A7
aka 717
May 30, 2004
"Stephan" wrote in message
"jjs" wrote in message
In article <nucuc.17432$>, "Wilder and
Wilder" wrote:

Total crap.
National Geographic has been accepting images from Digital cameras for
over
a year. Now that is the definative publication for picture quality.
Who
the
hell are Arizona Highways anyway? Christ… What is Arazona? Does
anyone
actually read the backwater magazine anyway?

And your point is? NG has been accepting B&W forever, too. 🙂 Arizona Highways was referring to pictures it also uses for exhibitions, if that helps.

No, there were talking about their out of this world quality, see here: "But an 11-megapixel capture is not nearly large enough for the sharp, high-resolution full-page reproductions we strive for on the printed pages of Arizona Highways magazine at 300 dots per inch"
My guess is that there are no stores offering digital cameras along Arizona’s highway’s yet or that Mr. Ensenberger is a Hasselblad or Leica user.

Stephan

Arizona Highways is printed in half tone, isn’t it, at
about 150-200 lines/inch. At the norm of 2.0-2.2
X lpi = ppi, then a scan or digital photo should be
from 300 ppi to 440 ppi.

That’s the way I figure it. Please correct me. It’s been a while.
A7
aka 717
May 30, 2004
"Stephan" wrote in message
"Not for Publication" wrote in message
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to
surprising
large dimensions and produce good to very good results… But then my
python
must surely be bigger than yours because of all the snake oil, eh?

Nobody would expect you to want to know you got ripped off. GF is not any better than Stair Interpolation and Stair interpolation can
be
replaced by a home made, free, action.

Stephan

Or a droplet.
B
bhilton665
May 30, 2004
From: "Stephan"

No, there were talking about their out of this world quality, see here: "But an 11-megapixel capture is not nearly large enough for the sharp, high-resolution full-page reproductions we strive for on the printed pages of Arizona Highways magazine at 300 dots per inch"

Highways typically prefers 4×5" chromes and drum scans from that. They’ll take medium format (a friend got the cover shot a couple of times with 6×4.5 cm but it’s uncommon) but prefer large format and probably 80-90% of the full spread shots are taken with 4×5. They rarely print from 35 mm except for the occasional wildlife or action shot. It’s actually a very highly regarded magazine for the quality of its printing.

Most of us who’ve actually used the 11 Mpixel body he mentions (the Canon 1Ds, which I use) feel it’s better than 35 mm but not up to medium format standards, and since this magazine pefers large format over MF it’s no wonder they aren’t switching over to digital yet. On the other hand if you know how to rez up the files with the best techniques and use edge sharpening on the rezzed up file you can make very nice large prints from the 1Ds, but magazines don’t want to go to this trouble when they can just scan large format instead.

My guess is that there are no stores offering digital cameras along Arizona’s highway’s yet or that Mr. Ensenberger is a Hasselblad or Leica user.

I did a multi-day hike down Paria Canyon with Ensenberger 12 years ago and he was lugging a Pentax 6×7 system, which they probably consider entry level gear for that particular magazine. The two pros who often contribute to the magazine and who led this trip (Jack Dykinga and Gary Ladd) both had 4×5’s, as did many of the other participants in the workshop. Blad would be marginally OK with this group, Leica wouldn’t cut it 🙂 Though Dykinga did use Leicas in his journalism days when he won a Pulitzer Prize, before taking the vow of poverty and becoming a landscape photographer.

It’s no big deal guys, they’re just saying they prefer large format and even the best Canon dSLR’s don’t match that. No surprise there.

Bill
XT
xalinai_Two
May 30, 2004
On Fri, 28 May 2004 09:02:15 -0700, J. A. Mc.
wrote:

On Thu, 27 May 2004 06:53:11 +1000, "Not for Publication" found these unused words floating about:

The problem with narrow minded people is they think the world revolves around their ideas.
This would be a self-description?

The day you can define a pixel as an element of linear
measurement, will be the day I start printing them.
Got plenty of ink/toner and paper?

In a world that has no other means of maesurement, pixels already are an element of linear masurement – the size of icons and on screen objects are measured in pixels, so are images in the web.

A pixel can easily be defined as having a linear measurement when referenced by dpi. THAT’s the whole point of having the dpi MARKER in the file. That it can be altered, that’s a function of modern technology.

pixel = 1/dpi in inches

This is valid where you can measure in inches – real world objects like printed images.

Until then, the only process of measuring an image for printing is in dots or lines. To print a 1200×1600 72 dpi image at 300 dpi requires the image to be interpolated up to that size.

The process of printing a 1200×1600 image at 300ppi requires no interpolation, as well as printing it at 72ppi – the resulting sizes will be different.

There are different procedures available to reduce the visibility of the pixel structure of the image printed at 72dpi but none of them will make it as clear or sharp as a 300ppi image of 16.67×22.22 inches.

And as ppi is pixels/inches, an image can never be 72ppi and 300ppi the same time as "printing a 72ppi image at 300ppi" suggests.

Michael
XT
xalinai_Two
May 30, 2004
On 29 May 2004 14:59:34 GMT, (Tacit) wrote:

Eventually the widespread use of including dpi in the measurement of an image’s size and quality will become the norm and traditionalists will forever morn the passing of yet another dead pixel.

True story: When i was working professional prepress at a trade shop called Dimension, we had a job order come in one day where the client had asked for a transparency to be scanned such that the scan would be 9 by 12 inches at 300 dpi.

Now, for the past thirty years, Dimension’s clients had been art directors and serious advertising professionals at big-name advertising agencies, so they never made that particular mistake. Lately, as more and more companies attempt (usually with dismal results) tosave money by bringing their advertising in-house, the experience and skill of Dimension’s client has dropped significantly.

Anyway, the job bag was passed to the scanner operator. This particular scanner operator, with 28 years’ experience running a drum scanner, was completely flummoxed; he had no idea what to do. He came to me and said "How can I make a scan at 300 dpi? That doesn’t make any sense! Do they want a prescreened halftone at 300 lines per inch? What the hell are they talking about?"
I laughed and explained, "Don’t sweat it, just make a 300 pixel per inch scan. The job’s for an ignoramous amateur who thinks "dpi" and "ppi" mean the same thing."

Sadly, five years later, the ignoramous amateurs seem to outnumber the skilled professionals even in the professional design and advertising industries.

The problem is that manufacturers on the input and on the output side use the same expression "DPI" for their very different purposes.

The scanner manufacturer calls full color pixels "Dots" and wouldn’t mind to use PPI for the same thing. The printer manufacturer uses the same "Dots" for the density his devices can place ink drops and he would be really unhappy if he were forced to advertise the actual PPI the printers can achieve on various sorts of paper. And as many companies make both, printers and scanners, the reason why there is no change in units should be obvious.

Michael
U
Uni
May 30, 2004
Xalinai wrote:
On 27 May 2004 14:36:20 GMT, (Tacit) wrote:

You can not print a 1600x1200pixel/72dpi image at 300dpi.

Yes, you can; the resulting print is 5.33 by 4 inches in dimension.

No. The printed image has a size and you can determine pixels per inch using a ruler and your knowledge about the number of pixels. If you can’t apply the ruler to the image the units on the ruler have no meaning to the image.

A digital image does have a resolution. This resolution, measured in pixels

Up to here I agree…

per
inch, is stored as part of the file, usually in the file’s header. The resolution makes no difference until the image is printed; nevertheless, it is still a property of the file, and Photoshop will show it as such.

…here not.

We both know it is irrelevant until the image is printed and it stays irrelevant whether Photoshop or the pope in Rome shows it.

Please keep in mind, this (resolution/density) issue pertains to Photoshop, ONLY. Not all graphic viewers and editors follow this!!!!!!

🙂

Here, have a clip:
http://www.angelfire.com/empire/abpsp/uni_stuff/uni_romance_ pt_5.mpg

🙂

Uni
U
Uni
May 30, 2004
Johan W. Elzenga wrote:
Tacit wrote:

Consumer and prosumer digital cameras tend to have a lower dynamic range than film. That means that while the film can still capture detail in the highlights and shadows, the digital image just shows white in the highlights and/or black in the shadows. (It’s the shadow end that’s typically most problematic for digital cameras.)

That website is not talking about consumer of prosumer digital cameras. There are no consumer or prosumer cameras with 11 Mpixels.

I believe I saw one in a Best Buys department store. It was a Nikon, I believe!

Uni

U
Uni
May 30, 2004
Wilder and Wilder wrote:
Total crap.
National Geographic has been accepting images from Digital cameras for over a year. Now that is the definative publication for picture quality. Who the hell are Arizona Highways anyway? Christ… What is Arazona? Does anyone actually read the backwater magazine anyway?

Well, I do know manufactures are using digital images to help sell their products. Also, it’s not uncommon to see advertisements in magazines that use digital images, too. You can always spot them and their jaggies.

🙂

Uni

"jjs" wrote in message

One last post, perhaps. Imaging for publication is not like making inkjet prints at home or friends, or undemanding employers. Photographers, read this: http://www.arizonahighways.com/page.cfm?name=Photo_Talk803
Rather daunting, isn’t it?

T
tacitr
May 30, 2004
National Geographic has been accepting images from Digital cameras for over a year.

Newsweek has been accepting digital images for several years. Your point is?

This has nothing to do with how good the images are; a critical reader can spot the digital images 10 out of 10 times. It has everything to do with the nature of the publication; Newsweek journalists need to be able to provide images on a very short timetable, and National Geographic prints images takein in extremely remote locations where film services and shipping services are unavailable.

A digital image beamed to the publication over satellite is often the only viable way to get images from remote places. the fact that the images are lower in quality is an accepted trade-off. It’s about convenience, not quality.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
V
Voivod
May 30, 2004
On Sun, 30 May 2004 14:13:15 -0400, Uni
scribbled:

Well, I do know

You of all people should never start a sentence with those four words.
S
Stephan
May 30, 2004
"aka 717" wrote in message

Arizona Highways is printed in half tone, isn’t it, at
about 150-200 lines/inch. At the norm of 2.0-2.2
X lpi = ppi, then a scan or digital photo should be
from 300 ppi to 440 ppi.

That’s the way I figure it. Please correct me. It’s been a while.

I won’t correct you.
All I know is that every day (in other states than Arizona), photographers produce digital files that get printed in high quality, glossy magazines. These guys are living in the past and/or are film snobs.

Stephan
N
nomail
May 30, 2004
Tacit wrote:

National Geographic has been accepting images from Digital cameras for over a year.

Newsweek has been accepting digital images for several years. Your point is?
This has nothing to do with how good the images are; a critical reader can spot the digital images 10 out of 10 times. It has everything to do with the nature of the publication; Newsweek journalists need to be able to provide images on a very short timetable, and National Geographic prints images takein in extremely remote locations where film services and shipping services are unavailable.

A digital image beamed to the publication over satellite is often the only viable way to get images from remote places. the fact that the images are lower in quality is an accepted trade-off. It’s about convenience, not quality.

Yeah, right. Of course National Geographic has never worked in remote places before there were digital cameras. Because there was no way to ship the films out, they never went any further than Disneyland. Only now they start to discover our world.


Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/
CC
Chris Cox
May 30, 2004
In article , Tacit
wrote:
Consumer and prosumer digital cameras tend to have a lower dynamic range than film. That means that while the film can still capture detail in the highlights
and shadows, the digital image just shows white in the highlights and/or black in the shadows. (It’s the shadow end that’s typically most problematic for digital cameras.)

You need to qualify that.

Current digital cameras have about the same dynamic range as slide film. But both slide and digital cameras have less dynamic range than negative film.

Chris
U
Uni
May 31, 2004
Voivod wrote:
On Sun, 30 May 2004 14:13:15 -0400, Uni
scribbled:

Well, I do know

You of all people should never start a sentence with those four words.

Oh, you, again!

Why not situate yourself in a group where they use software that you can handle?

Windows Paint group, That Way!! —->

🙂

Uni

U
Uni
May 31, 2004
Chris Cox wrote:
In article , Tacit
wrote:

Consumer and prosumer digital cameras tend to have a lower dynamic range than film. That means that while the film can still capture detail in the highlights
and shadows, the digital image just shows white in the highlights and/or black in the shadows. (It’s the shadow end that’s typically most problematic for digital cameras.)

You need to qualify that.

Current digital cameras have about the same dynamic range as slide film.

Whoa, Tacit receives a lesson in digital photography!

🙂

Uni

But both slide and digital cameras have less dynamic range than negative film.

Chris
J
jaSPAMc
May 31, 2004
On Sun, 30 May 2004 14:13:15 -0400, Uni found
these unused words floating about:

Wilder and Wilder wrote:
Total crap.
National Geographic has been accepting images from Digital cameras for over a year. Now that is the definative publication for picture quality. Who the hell are Arizona Highways anyway? Christ… What is Arazona? Does anyone actually read the backwater magazine anyway?

Well, I do know manufactures are using digital images to help sell their products. Also, it’s not uncommon to see advertisements in magazines that use digital images, too. You can always spot them and their jaggies.
Yah … right … dream on – those are only from the cheapies issued to their ‘reporters’.
V
Voivod
May 31, 2004
On Sun, 30 May 2004 20:14:42 -0400, Uni
scribbled:

Why not situate yourself in a group where they use software that you can handle?

Why aren’t you bragging about how great a ‘graphics guru’ you are like you were in other groups? Oh, that’s right, Mike, you’re the laughing stock of usenet. Didn’t you also used to claim to be an engineer?
M
Mike
May 31, 2004
in article , Voivod at
wrote on 05/30/2004 6:41 PM:

On Sun, 30 May 2004 20:14:42 -0400, Uni
scribbled:

Why not situate yourself in a group where they use software that you can handle?

Why aren’t you bragging about how great a ‘graphics guru’ you are like you were in other groups? Oh, that’s right, Mike, you’re the laughing stock of usenet. Didn’t you also used to claim to be an engineer?

I like how you are still confused about who Uni is.

hahahaha.

Tell me how smart you are again.

":^) ®
WA
Wilder and Wilder
May 31, 2004
Pardon me Stephen but who said GF was better than SA?
Certainly not me.

"Stephan" wrote in message
"Not for Publication" wrote in message
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to
surprising
large dimensions and produce good to very good results… But then my
python
must surely be bigger than yours because of all the snake oil, eh?

Nobody would expect you to want to know you got ripped off. GF is not any better than Stair Interpolation and Stair interpolation can
be
replaced by a home made, free, action.

Stephan

U
Uni
May 31, 2004
Not for Publication wrote:
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to surprising large dimensions and produce good to very good results…

Amen, brother! GF can’t be beat!

http://community.webshots.com/photo/42670345/47515893EPZDBe

🙂

Uni

But then my python
must surely be bigger than yours because of all the snake oil, eh?
"jjs" wrote in message

In article <_XVtc.15963$>, "Wilder and
Wilder" wrote:

I certainly learned that many people vehemently believe their own opinions… Even if they differ from what others do in day to day use.
Right

at the start I said the only way the OP would achieve his aim was to interpolate the image up to 300 dpi before printing.

I think that started the fiasco where all the Pixels got arrested by the
dpi

and so the tale continues with no one giving an inch to anyone else…
It

was you, too John, who first started the row over printing the image and Booo’d me for suggesting it maybe possible if interpolated… Geezzzz!

The "Booo" was for your recommendation of Genuine Fractals, aka: Snake

Oil.

U
Uni
May 31, 2004
Voivod wrote:
On Sun, 30 May 2004 20:14:42 -0400, Uni
scribbled:

Why not situate yourself in a group where they use software that you can handle?

Why aren’t you bragging about how great a ‘graphics guru’ you are like you were in other groups? Oh, that’s right, Mike, you’re the laughing stock of usenet. Didn’t you also used to claim to be an engineer?

Boring People, That Way!!! —->

🙂

Twerp.

🙂

Move along.

🙂

Uni
V
Voivod
May 31, 2004
On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Voivod wrote:
On Sun, 30 May 2004 20:14:42 -0400, Uni
scribbled:

Why not situate yourself in a group where they use software that you can handle?

Why aren’t you bragging about how great a ‘graphics guru’ you are like you were in other groups? Oh, that’s right, Mike, you’re the laughing stock of usenet. Didn’t you also used to claim to be an engineer?

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

🙂

Twerp.

🙂

Move along.

🙂

Uni
A
Aratzio
May 31, 2004
in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

hahahaha.
S
Stephan
May 31, 2004
"Wilder_4_awhile" wrote in message
Pardon me Stephen but who said GF was better than SA?
Certainly not me.
Anyone stupid or mis-informed enough to buy it of course.

Stephan

"Stephan" wrote in message
"Not for Publication" wrote in message
I’ll pass that one over. I use GF daily. It has oddities but it most certainly can enlarge basically good, low resolution images to
surprising
large dimensions and produce good to very good results… But then my
python
must surely be bigger than yours because of all the snake oil, eh?

Nobody would expect you to want to know you got ripped off. GF is not any better than Stair Interpolation and Stair interpolation
can
be
replaced by a home made, free, action.

Stephan

V
Voivod
May 31, 2004
On Mon, 31 May 2004 00:01:53 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

Odd, you yourself claimed Uni was ArtistMike just a short while ago…

http://www.google.com/groups?selm=gjqd805pc5qk1j18c28ape2qug n5vqer77%404ax.com&output=gplain

hahahaha.

And wasn’t this your proof for it?
http://groups.google.com/groups?selm=BA7C92F3.37843%25mike%4 0artistmike.com&output=gplain
A
Aratzio
May 31, 2004
in article , Voivod at
wrote on 05/31/2004 3:15 AM:

On Mon, 31 May 2004 00:01:53 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

Odd, you yourself claimed Uni was ArtistMike just a short while ago…
http://www.google.com/groups?selm=gjqd805pc5qk1j18c28ape2qug n5vqer77%404ax.com &output=gplain

That was the fake Aratzio writing that message.
U
Uni
May 31, 2004
Aratzio wrote:
in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.
hahahaha.

He’s not too bright.

🙂

Uni

V
Voivod
May 31, 2004
On Mon, 31 May 2004 09:43:33 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/31/2004 3:15 AM:

On Mon, 31 May 2004 00:01:53 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

Odd, you yourself claimed Uni was ArtistMike just a short while ago…
http://www.google.com/groups?selm=gjqd805pc5qk1j18c28ape2qug n5vqer77%404ax.com &output=gplain

That was the fake Aratzio writing that message.

Odd how you cut out the link that mates Uni and ArtistMike into one being….

Here, I’ll put it back in:

And wasn’t this your proof for it?
http://groups.google.com/groups?selm=BA7C92F3.37843%25mike%4 0artistmike.com&output=gplain
T
tacitr
Jun 1, 2004
Yeah, right. Of course National Geographic has never worked in remote places before there were digital cameras. Because there was no way to ship the films out, they never went any further than Disneyland. Only now they start to discover our world.

National Geographic has long used film, and prefers film. National Geographic now accepts digital images because sometimes, there is little alternative–not because digital is as good as film. It’s a matter of convenience, not quality–by using digital images, they can sometimes get images they could not have gotten as easily or as quickly before.


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
N
nomail
Jun 1, 2004
Tacit wrote:

Yeah, right. Of course National Geographic has never worked in remote places before there were digital cameras. Because there was no way to ship the films out, they never went any further than Disneyland. Only now they start to discover our world.

National Geographic has long used film, and prefers film. National Geographic now accepts digital images because sometimes, there is little alternative–not because digital is as good as film. It’s a matter of convenience, not quality–by using digital images, they can sometimes get images they could not have gotten as easily or as quickly before.

The choice is always a compromise between quality and convenience. If that wasn’t the case, National Geographic would only accept 8×10 inch film, not medium format film, 35mm film, or indeed digital. However, National Geographic does have a certain (and pretty high) quality standard. If they didn’t think digital meets that standard, they wouldn’t accept it, period. Even if there is no alternative.

The fact that they do not only accept digital, but even publish full two-page spreads from it, tells me they do indeed think that digital is as good as (or at least extremely close to) 35mm film. Even if they accept digital as a compromise, they don’t need to use such large images (and wouldn’t if they thought the quality wasn’t up to that).


Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/
U
Uni
Jun 2, 2004
Voivod wrote:
On Mon, 31 May 2004 09:43:33 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/31/2004 3:15 AM:

On Mon, 31 May 2004 00:01:53 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

Odd, you yourself claimed Uni was ArtistMike just a short while ago…
http://www.google.com/groups?selm=gjqd805pc5qk1j18c28ape2qug n5vqer77%404ax.com &output=gplain

That was the fake Aratzio writing that message.

Odd how you cut out the link that mates Uni and ArtistMike into one being….

Here, I’ll put it back in:

And wasn’t this your proof for it?
http://groups.google.com/groups?selm=BA7C92F3.37843%25mike%4 0artistmike.com&output=gplain

Sheesh, you’d make a lousy detective.

🙂

Uni
S
Shamus
Jun 2, 2004
in article , Uni at
wrote on 06/01/2004 9:54 PM:

Voivod wrote:
On Mon, 31 May 2004 09:43:33 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/31/2004 3:15 AM:

On Mon, 31 May 2004 00:01:53 -0700, Aratzio
scribbled:

in article , Voivod at
wrote on 05/30/2004 10:10 PM:

On Mon, 31 May 2004 00:32:12 -0400, Uni
scribbled:

Boring People, That Way!!! —->

I don’t think anyone really would want directions to your house, Mike.

I like how you are still confused about who you are writing to.

Odd, you yourself claimed Uni was ArtistMike just a short while ago…
http://www.google.com/groups?selm=gjqd805pc5qk1j18c28ape2qug n5vqer77%404ax. com
&output=gplain

That was the fake Aratzio writing that message.

Odd how you cut out the link that mates Uni and ArtistMike into one being….

Here, I’ll put it back in:

And wasn’t this your proof for it?
http://groups.google.com/groups?selm=BA7C92F3.37843%25mike%4 0artistmike.com&o utput=gplain

Sheesh, you’d make a lousy detective.

🙂

Uni

What do you expect from a goofball on Usenet.
-xiray-
Jun 3, 2004
On 29 May 2004 14:59:34 GMT, (Tacit) wrote:

I laughed and explained, "Don’t sweat it, just make a 300 pixel per inch scan. The job’s for an ignoramous amateur who thinks "dpi" and "ppi" mean the same thing."

For ignoramous amateurs? Guess you’ve not noticed that many of the companies that sell scanners (both low and high end) rate them with a DPI number and only some companies use the PPI term.

Seems to me that the fine distinction has really only come up in arguments in the last couple of years.

If I were told that a tiff file is 300 dpi, I’d know exactly what that means. If I were told that a halftone was a 150 line screen I’d know exactly what that means.

Why some people think that the same term can’t mean different things in different contexts is beyond me.

PPI, after all, also means "pages per inch" and nobody quibbles about that.
T
tacitr
Jun 3, 2004
For ignoramous amateurs? Guess you’ve not noticed that many of the companies that sell scanners (both low and high end) rate them with a DPI number and only some companies use the PPI term.

Scanner copanies sell to…people outside the prepress and graphic arts industry. Who do not know what "pixels per inch" means.

Seems to me that the fine distinction has really only come up in arguments in the last couple of years.

It’s come up since people with little formal training or education have begun entering the design business, bringing their errors and their misconceptions with them. This is both a good and a bad thing–good, because there are more people than ever before doing design; bad, because there is more bad design in the world that would be fixed by just a little bit of education.

Why some people think that the same term can’t mean different things in different contexts is beyond me.

The same term can mean different things–but the fact is, referring to a continuous-tone image in terms of "dots" is simply wrong, just as referring to a car as a "horse" would be wrong.

We think in language; fuzzy language leads to fuzzy thought.

In this particular case, fuzzy grasp of the difference between "dots" and "pixels" leads to people coming on this newsgroup and saying "I have a 28,800 dpi Epson printer, but when I scan my pictures at 28,800 dpi to print them out, the files are huge!"


Biohazard? Radiation hazard? SO last-century.
Nanohazard T-shirts now available! http://www.villaintees.com Art, literature, shareware, polyamory, kink, and more:
http://www.xeromag.com/franklin.html
B
Brian
Jun 3, 2004
For ignoramous amateurs? Guess you’ve not noticed that many of the companies that sell scanners (both low and high end) rate them with a DPI number

And they are quite wrong in doing so. Anyone who measures digital image resolution in "dots" is using incorrect terminology, period; regardless of who the company or person in question may be, they’re still 100% wrong.

Why some people think that the same term can’t mean different things in different contexts is beyond me.

Because they are NOT the same thing, and the only reason this has come up more and more often over the last few years is the deluge of neophytes calling themselves graphic artists who don’t understand what the terminology means or what it refers to, and for whatever reason don’t care to.

A digital image is constructed of pixels – there are no dots in a digital image, it’s impossible. Conversely, a printer, imagesetter, platesetter, etc. outputs using dots – there are no pixels involved. See how nicely the proper terminology works when the difference is made clear? The problem is that far too many people are far too unwilling to learn anything new; "my scanner calls it DPI so therefore it is" seems to be the prevailing – but woefully incorrect – attitude.

PPI, after all, also means "pages per inch" and nobody quibbles about that.

That doesn’t matter one iota, because that use of PPI is not wrong – PPI legitimately is used to mean both pixels per inch, and pages per inch, depending on context. DPI is not a legitimate measurement of image resolution under any circumstances.
J
john
Jun 3, 2004
Would it be appropriate, or even feasible for an ISO, ANSI, ASA, DIN, LSMFT or _someone_ to specify, for example, _exactly_ what Samples Per Inch (_not_ "SPI" which is taken) means for scanners, digicams and other image capture devices? Or have they? (Of course, I’d rather Samples Per Centimeter, but I’ll take what we can get.)

It would be a start.
XT
xalinai_Two
Jun 4, 2004
On Thu, 03 Jun 2004 17:08:41 -0500, (jjs)
wrote:

Would it be appropriate, or even feasible for an ISO, ANSI, ASA, DIN, LSMFT or _someone_ to specify, for example, _exactly_ what Samples Per Inch (_not_ "SPI" which is taken) means for scanners, digicams and other image capture devices? Or have they? (Of course, I’d rather Samples Per Centimeter, but I’ll take what we can get.)

It would be a start.

Samples per inch seems to be a fine definition as it restricts itself to input devices.

But you still have to specify whether you measure the CCD chip (like some camera manufacturers do) or the object size (like for scanning someting).

And then: If there is interpolation involved, how do you convert samples per inch into pixels per inch?

Wouldn’t you just add another element to existing confusion?

Michael
J
john
Jun 4, 2004
In article ,
(Xalinai) wrote:

On Thu, 03 Jun 2004 17:08:41 -0500, (jjs)
wrote:

Would it be appropriate, or even feasible for an ISO, ANSI, ASA, DIN, LSMFT or _someone_ to specify, for example, _exactly_ what Samples Per Inch (_not_ "SPI" which is taken) means for scanners, digicams and other image capture devices? Or have they? (Of course, I’d rather Samples Per Centimeter, but I’ll take what we can get.)

It would be a start.

Samples per inch seems to be a fine definition as it restricts itself to input devices.

But you still have to specify whether you measure the CCD chip (like some camera manufacturers do) or the object size (like for scanning someting).

And then: If there is interpolation involved, how do you convert samples per inch into pixels per inch?

Wouldn’t you just add another element to existing confusion?

I would hope that agencies such as those listed above would give strident requisites concerning exactly those issues and therefore eliminate the confusion.
B
Brian
Jun 4, 2004
Wouldn’t you just add another element to existing confusion?

As long as the terminology was clearly understood and used properly, not at all. The PPI vs DPI issue is confusing solely because far too many people insist on using the two terms interchangeably, refusing to understand the difference and to use each in its proper context.
U
Uni
Jun 5, 2004
Voivod wrote:
On Sat, 29 May 2004 06:04:19 GMT, "Wilder and Wilder" scribbled:

Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description.

Ladies and gentlemen – In this corner, wearing polka dots, weighing in at 98 lbs it’s the DPI Warrior! And in the other corner, weighing in at several ounces (brain included) it’s…. me, Void..

🙂

Uni

U
Uni
Jun 5, 2004
jjs wrote:
Would it be appropriate, or even feasible for an ISO, ANSI, ASA, DIN, LSMFT or _someone_ to specify, for example, _exactly_ what Samples Per Inch (_not_ "SPI" which is taken) means for scanners, digicams and other image capture devices? Or have they? (Of course, I’d rather Samples Per Centimeter, but I’ll take what we can get.)

It’s a concern of no one. Who cares if you state DPI, LPI, PPI, Dogs Per Inch, Lambs Per Inch or Parakeets Per Inch? That MAIN thing, they’re all Per Inch!

🙂

Uni

It would be a start.
V
Voivod
Jun 5, 2004
On Sat, 05 Jun 2004 13:02:57 -0400, Uni
scribbled:

Voivod wrote:
On Sat, 29 May 2004 06:04:19 GMT, "Wilder and Wilder" scribbled:

Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description.

Ladies and gentlemen – In this corner, wearing polka dots, weighing in at 98 lbs it’s the DPI Warrior! And in the other corner, weighing in at several ounces (brain included) it’s…. me, Void..

And you’re back to having to edit people’s posts to get anyone to pay attention to you. Did you start off trying to be the most ridiculed, pathetic troll on usenet or did that just happen as you realized you have no social skills whatsoever?
U
Uni
Jun 6, 2004
Voivod wrote:
On Sat, 05 Jun 2004 13:02:57 -0400, Uni
scribbled:

Voivod wrote:

On Sat, 29 May 2004 06:04:19 GMT, "Wilder and Wilder" scribbled:

Your argument is flawed in that "widespread" industry usage invariably leads to industry adoption of that description.

Ladies and gentlemen – In this corner, wearing polka dots, weighing in at 98 lbs it’s the DPI Warrior! And in the other corner, weighing in at several ounces (brain included) it’s…. me, Void..

And you’re back to having to edit people’s posts to get anyone to pay attention to you. Did you start off trying to be the most ridiculed, pathetic troll on usenet or did that just happen as you realized you have no social skills whatsoever?

Excuse me, don’t you have a bone to chew on?

🙂

Uni
GP
Geri Panties
Jun 6, 2004
in article , Voivod at
wrote on 06/05/2004 1:00 PM:

Did you start off trying to be the most ridiculed,
pathetic troll on usenet or did that just happen as you realized you have no social skills whatsoever?

You really have no self control, do you.
MV
Matti Vuori
Jun 6, 2004
Uni wrote in
news::
It’s a concern of no one. Who cares if you state DPI, LPI, PPI, Dogs Per Inch, Lambs Per Inch or Parakeets Per Inch?

Those do, who understand the difference between dogs and lambs.


Matti Vuori, <http://sivut.koti.soon.fi/mvuori/index-e.htm>
U
Uni
Jun 6, 2004
Geri Panties wrote:
in article , Voivod at
wrote on 06/05/2004 1:00 PM:

Did you start off trying to be the most ridiculed,
pathetic troll on usenet or did that just happen as you realized you have no social skills whatsoever?

You really have no self control, do you.

Void lives in a fantasy world.

🙂

Uni

V
Voivod
Jun 6, 2004
On Sun, 06 Jun 2004 17:33:07 -0400, Uni
scribbled:

Geri Panties wrote:
in article , Voivod at
wrote on 06/05/2004 1:00 PM:

Did you start off trying to be the most ridiculed,
pathetic troll on usenet or did that just happen as you realized you have no social skills whatsoever?

You really have no self control, do you.

Void lives in a fantasy world.

Coming from someone who proclaims himself to be a ‘graphics guru’, a ‘professional engineer’ and a ‘usenet manager’ that’s really rich.
-xiray-
Jun 9, 2004
On Sat, 05 Jun 2004 13:08:46 -0400, Uni
wrote:

It’s a concern of no one. Who cares if you state DPI, LPI, PPI, Dogs Per Inch, Lambs Per Inch or Parakeets Per Inch? That MAIN thing, they’re all Per Inch!

Point taken. Agreed.

Also, can’t we all agree that dpi and ppi are sometimes synonyms?
-xiray-
Jun 9, 2004
On 03 Jun 2004 20:37:19 GMT, (Tacit) wrote:

It’s come up since people with little formal training or education have begun entering the design business, bringing their errors and their misconceptions with them.

In addition to their misconceptions… they’re bringing their Macs. Probably part of the problem. <grins>
-xiray-
Jun 9, 2004
On Thu, 03 Jun 2004 16:49:38 -0400, Brian wrote:

A digital image is constructed of pixels

Technically… not true. Only the screen display of the digital file is actually pixels.
-xiray-
Jun 9, 2004
On Fri, 04 Jun 2004 16:45:30 -0400, Brian wrote:

Wouldn’t you just add another element to existing confusion?

As long as the terminology was clearly understood and used properly, not at all. The PPI vs DPI issue is confusing solely because far too many people insist on using the two terms interchangeably, refusing to understand the difference and to use each in its proper context.

On that I totally agree.

But I do so enjoy those designers that hand in 1440 ppi images because their inkjet is rated to print high quality images at 1440 dpi.
B
Brian
Jun 9, 2004
Also, can’t we all agree that dpi and ppi are sometimes synonyms?

Absolutely not, they are *never* synonyms regardless of common (mis)usage.
B
Brian
Jun 9, 2004
Technically… not true. Only the screen display of the digital file is actually pixels.

Sorry, you are wrong on this. What do you propose a digital image is composed of then?
XT
xalinai_Two
Jun 10, 2004
On Wed, 09 Jun 2004 19:45:10 GMT, -xiray- wrote:

On Sat, 05 Jun 2004 13:08:46 -0400, Uni
wrote:

It’s a concern of no one. Who cares if you state DPI, LPI, PPI, Dogs Per Inch, Lambs Per Inch or Parakeets Per Inch? That MAIN thing, they’re all Per Inch!

Point taken. Agreed.

Also, can’t we all agree that dpi and ppi are sometimes synonyms?

The only application where you can use both is thermo sublimation printing, where the color for each pixel is mixed independent from adjacent pixels, but only if you print one image pixel as one device pixel.

For the resolution of input devices (scanners) you should use "samples per inch" and in cases of resolutions lower than the devices technical ability you could specify whether only one sample is used for the final pixel or several CCD-cell-readings are interpolated for the pixel value.

For the resolution of printed matter you have DPI or LPI for the print technology used and PPI (usually a lower number) to express the relation between digital image size and the image size on the paper.

Michael
XT
xalinai_Two
Jun 10, 2004
On Wed, 09 Jun 2004 16:43:21 -0400, Brian wrote:

Technically… not true. Only the screen display of the digital file is actually pixels.

Sorry, you are wrong on this. What do you propose a digital image is composed of then?

Bytes. Between one Bit and several bytes per pixel and the rules for arranging them.

But I agree that this is a kind if nitpicking. The abstraction level most people work at is one higher: Pixels.

Michael
-xiray-
Jun 10, 2004
On Wed, 09 Jun 2004 16:42:51 -0400, Brian wrote:

Also, can’t we all agree that dpi and ppi are sometimes synonyms?

Absolutely not, they are *never* synonyms regardless of common (mis)usage.

Interestingly enough, the academics that compile dictionaries would disagree. You should see what you get when you look up "dpi."
-xiray-
Jun 10, 2004
On Thu, 10 Jun 2004 08:08:44 GMT, (Xalinai)
wrote:

But I agree that this is a kind if nitpicking. The abstraction level most people work at is one higher: Pixels.

Michael

Agreed. It is nitpicking. But that does seem to be what this thread is all about… nitpicking.
B
Brian
Jun 10, 2004
Interestingly enough, the academics that compile dictionaries would disagree.

And they would be wrong, regardless of their academic credentials.
-xiray-
Jun 11, 2004
On Thu, 10 Jun 2004 15:14:51 -0400, Brian wrote:

Interestingly enough, the academics that compile dictionaries would disagree.

And they would be wrong, regardless of their academic credentials.

Oh, Ok. You’re right then I guess. People don’t use the terms as synonyms. My mistake.

While we’re at it let’s also nitpick about how a pixel has 3 subpixel elements and discuss how that relates to the code in the digital file and the number of discrete and independent "dots" found in the linear measure of your screen.
B
Brian
Jun 11, 2004
Oh, Ok. You’re right then I guess. People don’t use the terms as synonyms. My mistake.

Oh no, people *do* use them as synonyms, yes indeed, but that doesn’t make it right just because they do.

While we’re at it let’s also nitpick…

You know, I fail to see how using the correct terminology is nitpicking in the slightest. There are NO dots in a digital image, period, therefore dots per inch is an invalid unit of measurement. Why this is so hard to understand and accept is beyond me…

Using DPI to describe the resolution of a digital image is about as correct as using horsepower to describe the gas mileage of your car.

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