Scale an image to actual size?

I often use the Crop Tool to get part of an image to print at actual size. For example, Crop: Width 7cm @ Resolution 600 pixels/inch (same as my printer), then select a known width of 7cm then crop and print.

I figure there must be a way without actually cropping the image, perhaps by selecting the known dimension.

I could do the math myself, but I figure Photoshop CS4 can do it for me.

Any suggestions?
--

Nigel M

If I'm discussing apples, please don't suggest bananas

Nigel Molesworth wrote:

I often use the Crop Tool to get part of an image to print at actual size. For example, Crop: Width 7cm @ Resolution 600 pixels/inch (same as my printer), then select a known width of 7cm then crop and print.
I figure there must be a way without actually cropping the image, perhaps by selecting the known dimension.

I could do the math myself, but I figure Photoshop CS4 can do it for me.
Any suggestions?

My suggestion is FORGET stuffs you do but do the basic standard cropping should do.

1. Select the CROP TOOL

2. Set the RATIO then crop to the RATIO you wanna print. Example if you

- want to print 4x6 then crop to 4x6

- want to print to 8x10 then crop to 8x10

That's it! no need to mess with 7cm 8cm 300PPI or 3000PPI which doesn't do any good but may cause problem.

On Wed, 28 Jan 2009 19:22:42 -0600, Joe wrote:

the basic standard cropping should do.

no need to mess with 7cm 8cm 300PPI or 3000PPI which doesn't do any good

[1] As stated, I want to do this without cropping - to keep the whole image
[2] The method I used works, but see [1]

Nigel Molesworth wrote:

On Wed, 28 Jan 2009 19:22:42 -0600, Joe wrote:

the basic standard cropping should do.

no need to mess with 7cm 8cm 300PPI or 3000PPI which doesn't do any good

[1] As stated, I want to do this without cropping - to keep the whole image [2] The method I used works, but see [1]

Select the area you want to print, use Print... and tick the "Selected area" checkbox. It may not change the preview, but it should print only the selection. Well, that's how it works with CS3..

Andrew

On Thu, 29 Jan 2009 11:41:09 -0000, "Andrew Morton" wrote:

Select the area you want to print, use Print... and tick the "Selected area"

Thanks, but this will only print the selected area. I want to SCALE the selected area to the actual size (as per OP).

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 11:41:09 -0000, "Andrew Morton" wrote:

Select the area you want to print, use Print... and tick the "Selected area"

Thanks, but this will only print the selected area. I want to SCALE the selected area to the actual size (as per OP).

I think you may be stuck with using your method, unless the "Scaled print size" box in conjunction with "Selected area" does what you'd expect it to do, despite the unhelpfulness of the preview (in CS3 - maybe it works in CS4).

When you write "the actual size", do you actually mean an arbitrarily specified size and resolution as opposed to the actual size and resolution of the image?

Andrew

Nigel Molesworth wrote:

On Wed, 28 Jan 2009 19:22:42 -0600, Joe wrote:

the basic standard cropping should do.

no need to mess with 7cm 8cm 300PPI or 3000PPI which doesn't do any good

[1] As stated, I want to do this without cropping - to keep the whole image

That's the RATIO is for.

- If ya wanna keep the whole image then need not to do anything to begin with.

[2] The method I used works, but see [1]

- If you change anything then it's either "doing something for nothing" or "messing thing up"

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 11:41:09 -0000, "Andrew Morton" wrote:

Select the area you want to print, use Print... and tick the "Selected area"

Thanks, but this will only print the selected area. I want to SCALE the selected area to the actual size (as per OP).

Again,

1. Learn to understand the meaning of the word "RATIO"

2. After you understand the meaning of "RATIO" then learn to take advantage of the CROP TOOL

3. You DO NOT want to use SCALE on any print cuz it isn't the right tool, cuz you either

- won't change anything

- or mess up the image (distortion)

Yes, I do read in other message you said it WORKS for you, and I still don't believe it.

Or

- Scale an Image to Actual Size = doing NOTHING or just leave it alone

- Scale an Image to Actual Ratio = doing NOTHING or leave it alone

- Scale an Image to *different* Size or Ratio = then Scale to whatever you want (you will end up with a messed up image).

On Thu, 29 Jan 2009 13:14:31 -0000, "Andrew Morton" wrote:

When you write "the actual size", do you actually mean an arbitrarily specified size and resolution as opposed to the actual size and resolution of the image?

Perhaps I didn't explain properly.

I have an image which is an arbitrary number of pixels wide. In the image is an object of know size, say a coin. I wish to print this image at 600dpi such that the coin comes out life-size, and the rest of the image is at this same scale.

Any clearer?

On Thu, 29 Jan 2009 10:12:52 -0600, Joe wrote:

[1] As stated, I want to do this without cropping - to keep the whole image

That's the RATIO is for.

Are you talking about aspect ratio? Nothing to do with what I mean.

Do you guys need to see an example? See below:

http://www.mercier.org.uk/temp/penny.jpg

This is an image of a penny, and a lid. You see it has been cropped to the sides of the penny, which has a width of 20.3mm. This was done by selecting Crop: Width 20.3mm @ Resolution 600 pixels/inch. If I print this on my 600dpi Laser printer, it comes out actual size. With me so far?

However, I don't want to crop the image, as I have now lost the subject of the image (the lid). I just want to automatically resize it so it prints at the same scale.

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 13:14:31 -0000, "Andrew Morton" wrote:

When you write "the actual size", do you actually mean an arbitrarily specified size and resolution as opposed to the actual size and resolution of the image?

Perhaps I didn't explain properly.

I have an image which is an arbitrary number of pixels wide. In the image is an object of know size, say a coin. I wish to print this image at 600dpi such that the coin comes out life-size, and the rest of the image is at this same scale.

Any clearer?

It seems like YOU are the one who needs to get clearer understanding of the whole thing.

- OK, lets say you wish to print the image at 600dpi, and the image is big enough. Then all you need to do is printing it as *smaller* scale.

Example if you have 1x1x600dpi (or ppi) then the MAX size of the print for 600-dpi (or PPI) should be *no* larger than 1"x1". Or if you want to print to 2x2" then the "DPI" (or PPI) should be lesser than 600dpi.

The same rule will apply to the "coin", "paper", "plastic", "regular
paper", "glossy photo paper" etc. cuz it doesn't matter. Or the MAIN thing is the total of W x H x R (or PPI).

- YES, you can sample the 1x1x600ppi to 1000x1000x6000-PPI (if you wish) but it won't be same as *original* and you won't get any better quality.

Example, you have 1 Dollar Bill, then you can have these limited combination.

- 100 cents

- 2 50-cents

- 4 25-cents

- 10 10-cents

- 20 5-cents

or combination like (1) 1-cents with (9) 10cents and so on. BUT you can't have (11) 10 cents or (21) 5-cents.

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 10:12:52 -0600, Joe wrote:

[1] As stated, I want to do this without cropping - to keep the whole image

That's the RATIO is for.

Are you talking about aspect ratio? Nothing to do with what I mean.
Do you guys need to see an example? See below:

http://www.mercier.org.uk/temp/penny.jpg

This is an image of a penny, and a lid. You see it has been cropped to the sides of the penny, which has a width of 20.3mm. This was done by selecting Crop: Width 20.3mm @ Resolution 600 pixels/inch. If I print this on my 600dpi Laser printer, it comes out actual size. With me so far?
However, I don't want to crop the image, as I have now lost the subject of the image (the lid). I just want to automatically resize it so it prints at the same scale.

As I said it doesn't matter if it's a round coin or rectangle dollar bill.

1. If you want the COIN only then you will have to CROP which give you 100% of the original resolution

2. The MAX resultion you can get will be the MAX of the original. IOW, if the PENNY.JPG has enough 20.3mm x 20.3mm x 600-ppi then sure you can, but it's less then whatever MAX is what you will get.

3. YES, you can tell Photoshop to resample to W x H x 600-ppi but it won't give you any better quality (see other message).

4. If you want to print the ROUND penny from rectangle photo then you will have to CROP.

5. If you try to turn (resample) the Rectangle Photo to Square (there is no round) then you will end up with OVAL penny.

Your sample is 480x1,460 x 100-ppi so if you want to print the *whole* image then you can print at

4.8" x 14.6" at 100-PPI

If you wanna print the *whole* thing at 600-ppi then you will get around

.5" x 2.4" x 600-ppi

And if you want to print the PENNY only at 600-ppi then you should have lesser than <.5" x .5" x 600-ppi

Also, printing at 600-ppi or even 6000-ppi using laser printer won't give you any better print .. cuz laser printer can only print to its MAX.

In article , Nigel
Molesworth wrote:

Do you guys need to see an example? See below:

http://www.mercier.org.uk/temp/penny.jpg

This is an image of a penny, and a lid. You see it has been cropped to the sides of the penny, which has a width of 20.3mm. This was done by selecting Crop: Width 20.3mm @ Resolution 600 pixels/inch. If I print this on my 600dpi Laser printer, it comes out actual size. With me so far?
However, I don't want to crop the image, as I have now lost the subject of the image (the lid). I just want to automatically resize it so it prints at the same scale.

I think the easiest thing to do would be to include a ruler in the scene. Since it's larger than the object you want, you can crop to any convenient increment on the ruler and have your 100% image. Keep in mind that perspective will change the relative sizes of the ruler and the object, sometimes dramatically.
Tom Nelson
Tom Nelson Photography

On Thu, 29 Jan 2009 15:26:44 -0600, Joe wrote:

1. If you want the COIN only then you will have to CROP which give you 100% of the original resolution

[rest snipped]

I fear you have not understood my requirement.

On Thu, 29 Jan 2009 22:45:43 +0000 (UTC), Tom Nelson
wrote:

I think the easiest thing to do would be to include a ruler in the scene. Since it's larger than the object you want, you can crop to any convenient increment on the ruler and have your 100% image.

Yes, sometimes I now include a ruler for this very reason. A lot of these photos were taken 5 years ago, before the idea to use them for size purposes came to me.

In article ,
Nigel Molesworth wrote:

On Thu, 29 Jan 2009 13:14:31 -0000, "Andrew Morton" wrote:

When you write "the actual size", do you actually mean an arbitrarily specified size and resolution as opposed to the actual size and resolution of the image?

Perhaps I didn't explain properly.

I have an image which is an arbitrary number of pixels wide. In the image is an object of know size, say a coin. I wish to print this image at 600dpi such that the coin comes out life-size, and the rest of the image is at this same scale.

Any clearer?

OK, you do _not_ want to take a portion of a 600 dpi image and print it at a specified size, say 4 x 6, correct? This was a bit confusing since there has been some discussion of what "100% crops" means.

You _do_ want to take an image of arbitrary scale and resolution and print it so that a known object in the image is 1:1 (life sized) _and_ the entire image is 600 dpi, correct?

I believe this would have to be done under "Image Size", you have to calculate the scale difference between the known object's current size (1:?) and the desired size (1:1), with "Resample Image" and "Constrain Proportions" checked and "600 dpi" as the final resolution.

If you want to preserve the original you can use "Save a copy as..." before resizing. Note that this may give you a larger or smaller final image than your desired print size. There are too many variables involved, specifically the difference in sizes of the known object, for it to be done automatically, but I certainly could be wrong, and there might be a plugin available that does exactly this.

If I got it completely wrong, I apologize. I haven't been following this thread closely.

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 10:12:52 -0600, Joe wrote:

[1] As stated, I want to do this without cropping - to keep the whole image

That's the RATIO is for.

Are you talking about aspect ratio? Nothing to do with what I mean.
Do you guys need to see an example? See below:

http://www.mercier.org.uk/temp/penny.jpg

This is an image of a penny, and a lid. You see it has been cropped to the sides of the penny, which has a width of 20.3mm. This was done by selecting Crop: Width 20.3mm @ Resolution 600 pixels/inch. If I print this on my 600dpi Laser printer, it comes out actual size. With me so far?
However, I don't want to crop the image, as I have now lost the subject of the image (the lid). I just want to automatically resize it so it prints at the same scale.

As I said it doesn't matter if it's a round coin or rectangle dollar bill.
1. If you want the COIN only then you will have to CROP which give you 100% of the original resolution

2. The MAX resultion you can get will be the MAX of the original. IOW, if the PENNY.JPG has enough 20.3mm x 20.3mm x 600-ppi then sure you can, but it's less then whatever MAX is what you will get.

3. YES, you can tell Photoshop to resample to W x H x 600-ppi but it won't give you any better quality (see other message).

4. If you want to print the ROUND penny from rectangle photo then you will have to CROP.

5. If you try to turn (resample) the Rectangle Photo to Square (there is no round) then you will end up with OVAL penny.

Your sample is 480x1,460 x 100-ppi so if you want to print the *whole* image then you can print at

4.8" x 14.6" at 100-PPI

If you wanna print the *whole* thing at 600-ppi then you will get around
.5" x 2.4" x 600-ppi

And if you want to print the PENNY only at 600-ppi then you should have lesser than <.5" x .5" x 600-ppi

Also, printing at 600-ppi or even 6000-ppi using laser printer won't give you any better print .. cuz laser printer can only print to its MAX.

I fear you have not understood my requirement.

Believe it or not, I know what your requirement more than you even think. And that's why I give more detail than what you really be able to take.

But it's sad that you are not only not at the level to get the point, you seem not happy to get the answer you want to hear. Sorry, I know it's disapointed you, but that is the way it goes and that's how I tell the real story.

Yup! I even give you another chance to RE-READ what you refused to read.

Nigel Molesworth wrote:

On Thu, 29 Jan 2009 22:45:43 +0000 (UTC), Tom Nelson
wrote:

I think the easiest thing to do would be to include a ruler in the scene. Since it's larger than the object you want, you can crop to any convenient increment on the ruler and have your 100% image.

Yes, sometimes I now include a ruler for this very reason. A lot of these photos were taken 5 years ago, before the idea to use them for size purposes came to me.

SIZE and RE-SIZE (and lot more) has always been available, so making an excuse about the photo was taken 5 years ago is a very sad and bad excuse. Reason

- You can always have the penny retaken not only at any moment but also using a higher resolution camera. And you can even use the real Macro Lens to take a stunning photo too.

- It's even sadder because that isn't the right excuse.

The man give you all the tools you need but you refuse to accept. Point your browser to www.google.com then search for

- "100% crop" which the man and I have been telling you

- You can search for "Cropping", "Resize", "Reasample" etc..

Inside the "resize" has quite a few advanced option, but I won't mention because you are not realy for it/them yet.

On Fri, 30 Jan 2009 12:41:06 -0600, Joe wrote:

You can always have the penny retaken

Oh dear me. You really have missed the point.

OK, I have the solution, many thanks to Steve Sprengel:

1) Convert your background image to a Layer if not already.

2) Select the Crop tool icon.

3) Before defining the crop area, in the crop-options up top, type in the dimensions of the object you are going to measure (the penny) specifying both the number and the units (like 4 in or 10 cm or something). If your object is round then you can specify one dimension accurately and make the other one very small, like 4 in x 1 mm.

4) Blank out the resolution field in the options if there is any number and/or units in it.

5) Click-drag your crop-marquee to encompass or span the object you entered the dimensions of (the lid). If you specified one dimension very small compared to the accurate one (like 80mm x 1mm) then you will have a long thin ruler you can drag across the object from one side to the other which may be easier than trying to guess a corner of a round object. Adjust the crop tool corners as needed to exactly match the object that you know the size of.

6) Make sure the crop tool option is set to Hide not Delete. This option won't be available if your image is not a layer so it needs to be a layer.

7) Click the Apply checkbox up top or just hit Enter.

8) Select Image / Reveal All from the menu.

9) Clear crop dimensions, then re-crop just the part of the image you want to print.

There you are, your image has the right scale for printing.

Nigel Molesworth wrote:

On Fri, 30 Jan 2009 12:41:06 -0600, Joe wrote:

You can always have the penny retaken

Oh dear me. You really have missed the point.

OK, I have the solution, many thanks to Steve Sprengel:

1) Convert your background image to a Layer if not already.
2) Select the Crop tool icon.

3) Before defining the crop area, in the crop-options up top, type in the dimensions of the object you are going to measure (the penny) specifying both the number and the units (like 4 in or 10 cm or something). If your object is round then you can specify one dimension accurately and make the other one very small, like 4 in x 1 mm.

4) Blank out the resolution field in the options if there is any number and/or units in it.

5) Click-drag your crop-marquee to encompass or span the object you entered the dimensions of (the lid). If you specified one dimension very small compared to the accurate one (like 80mm x 1mm) then you will have a long thin ruler you can drag across the object from one side to the other which may be easier than trying to guess a corner of a round object. Adjust the crop tool corners as needed to exactly match the object that you know the size of.

6) Make sure the crop tool option is set to Hide not Delete. This option won't be available if your image is not a layer so it needs to be a layer.
7) Click the Apply checkbox up top or just hit Enter.

8) Select Image / Reveal All from the menu.

9) Clear crop dimensions, then re-crop just the part of the image you want to print.

There you are, your image has the right scale for printing.

Hehehehehe with that many steps I don't think you will miss anything. But to make thing easier to remember, you need no more than ONE SINLE STEP

1. Select the CROP TOOL then CROP to the PENNY which will gve you 100% crop

That's it! no need to Hide/Show, no need to Delete or anything. And don't tell me I miss 8 points because I show you only single point.

On Sat, 31 Jan 2009 11:43:58 -0600, Joe wrote:

1. Select the CROP TOOL then CROP to the PENNY which will gve you 100% crop

Just how will this get the result I want?

Joe is consistently failing to see that his method crops away the image to the sides of the coin. You want the entire photo resized so the coin is actual size.

Nigel, your 8-step process didn't work for me in PSCS3. I got no Hide option, and cropping removed the edges of the image. In any case, it's more laborious than simply calculating the resize:

1. Use the Ruler tool (keyboard shortcut I) and measure the coin's size in pixels. Use the Info palette to read that number (we'll call it X).

2. Calculate the desired size (width x resolution). We'll call that Y.

3. Using a calculator, divide Y/X. That is your resize ratio.

3. In the Image>Image Size dialog click the triangle next to Document Size (inches/centimeters/pixels or whatever) and select Percent. Put in the desired percentage.

4. Hit Enter.

Example:
1. Coin is 825 pixels wide. You desire it to be 3 cm at 236 pixels/cm (that's 600 pixels/inch but it's easier to use a consistent measure).
2. 3x236=708 pixels wide. That's Y.
3. 708/825= 86%. Put that into the Image Size dialog.
4. Hit Enter.

Tom Nelson
Tom Nelson Photography

Nigel Molesworth wrote:

On Sat, 31 Jan 2009 11:43:58 -0600, Joe wrote:

1. Select the CROP TOOL then CROP to the PENNY which will gve you 100% crop

Just how will this get the result I want?

You DO NOT get thing you don't have. Do you get this far?

Or what you can get it the MAX of what the IMAGE has to offer, and that's it! do you get this far?

Or you won't be able to get what you want *until* you start worshipping me <bg>.

The problem that Tom doesn't know how Crop Tool work either. It's sad that someone is trying to correct other but doesn't understand the whole thing.

Joe wrote:

Nigel Molesworth wrote:

On Sat, 31 Jan 2009 11:43:58 -0600, Joe wrote:

1. Select the CROP TOOL then CROP to the PENNY which will gve you 100% crop

Just how will this get the result I want?

You DO NOT get thing you don't have. Do you get this far?
Or what you can get it the MAX of what the IMAGE has to offer, and that's it! do you get this far?

Or you won't be able to get what you want *until* you start worshipping me <bg>.

And since you are thinking of worshipping me so I give you a little more hint (someone else and I already several times before but you don't seem to get it).

- Since you want to print the ROUND shape (penny) and in the photoshop world "ROUND" = "SQUARE"

- And in the RATIO aspect world, it doesn't matter if you want 1:1 or 2:2 or 3:3 or 4:4 or 1000000:1000000 or more.

Cuz 1:1 will give you the *perfect* circle or *perfect* square

Cuz the 1:1 will give you the *exact* value of the 5000:5000 or 6000:6000 and so on

And you won't get more than 100% of whatever the MAX of the image. So just make 100% Crop of that sucker then print to whatever size you wish. IOW, with the 1:1 Ratio you can print to

1cm x 1cm
1" x 1"
10" x 10"
5 km x 5km
500mile x 500mile

and so on because they are the exact same RATIO. And if the image is capable of printing 500mile x 500mile x 600-ppi then sure you will get the 600-dpi quality (as someone has mentioned your laser printer ain't capable of doing 600-dpi).

IOW, you don't fullu understand the meaning of RATIO and what CROP Tool can or can't not do.

On Sat, 31 Jan 2009 20:37:24 +0000 (UTC), Tom Nelson
wrote:

Joe is consistently failing...

He's in my kill-file now.

Nigel, your 8-step process didn't work for me in PSCS3...

Did you see the bit that says: "This option won't be available if your image is not a layer so it needs to be a layer".

Nigel Molesworth wrote:

On Sat, 31 Jan 2009 20:37:24 +0000 (UTC), Tom Nelson
wrote:

Joe is consistently failing...

He's in my kill-file now.

Hahahah you have better cuz stupid like you just won't get very far.

Nigel, your 8-step process didn't work for me in PSCS3...

Did you see the bit that says: "This option won't be available if your image is not a layer so it needs to be a layer".