Enlarge small file

"My View" <no spam > wrote in message

I have a 280kB jpeg file that a friend wants me to manipulate (ie remove a couple of people from a group shot).

This was as big a file as I could get.

The size of the file is determined by the amount of compression. What counts is the size in memory of the image. In particular the number of pixels. You can’t determine number of pixels merely by looking at the disk space that the file requires.

The file size will reduce even further after I remove parts of the image.

Probably not much since you are going to replace the people with something else.

Is there a way to increase the file size to say 2 to 3Mb so I have a bit more meat to deal with?

regards

PeterH

After you get the image in memory, decide what, if any, exptrapolation may be in order. I only use a very moderate extrapolation.
Jim

In article <kN_cf.14737$>, My View wrote:

I have a 280kB jpeg file that a friend wants me to manipulate (ie remove a couple of people from a group shot).

You’ve not much to work with, so I’d first save it as a PSD or Tiff. That way, any saves you make along the way won’t degrade it further. If you need to revert to jpeg, do so at the very end.

I’d use image/image size to get the file size up; bicubic is best. Others here might have some better ways of enlarging the file.

—

Roger

In article <kN_cf.14737$>,
"My View" <no spam > wrote:

couple of people from a group shot).

This was as big a file as I could get.

The file size will reduce even further after I remove parts of the image.
Is there a way to increase the file size to say 2 to 3Mb so I have a bit more meat to deal with?

Nothing–no program, no technique, nothing whatsoever–can enlarge a pixel-based image and create detail that does not exist in the original. It cannot be done.

You can use the Image Size command to enlarge the image, but the quality will decrease.

—
Art, photography, shareware, polyamory, literature, kink: all at http://www.xeromag.com/franklin.html

tacit wrote:

Nothing–no program, no technique, nothing whatsoever–can enlarge a pixel-based image and create detail that does not exist in the original. It cannot be done.

sure.

You can use the Image Size command to enlarge the image, but the quality will decrease.

No. The quality will stay the same. Yo neither gain nor lose anything.

BUT:

Enlarging a picture before doing image surgery is often a good idea. It makes exact, clean masking, copying, patching so much easier.

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

On Fri, 11 Nov 2005 20:36:45 +0100, "Greg N." wrote:

tacit wrote:

Nothing–no program, no technique, nothing whatsoever–can enlarge a pixel-based image and create detail that does not exist in the original. It cannot be done.

sure.

You can use the Image Size command to enlarge the image, but the quality will decrease.

No. The quality will stay the same. Yo neither gain nor lose anything.

thanx for the good news, Greg, wonder why we buy 6 & 8 mp cameras if we can get along with 1’s and only enlarge the pictures:-) Or is it for the other features?

Dave

DD wrote:

thanx for the good news, Greg, wonder why we buy 6 & 8 mp cameras if we can get along with 1’s and only enlarge the pictures:-) Or is it for the other features?

either you play stupid, or you are. I said you don’t gain any quality by enlarging the picture.

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

Greg N. wrote:

DD wrote:

thanx for the good news, Greg, wonder why we buy 6 & 8 mp cameras if we can get along with 1’s and only enlarge the pictures:-) Or is it for the other features?

either you play stupid, or you are. I said you don’t gain any quality by enlarging the picture.

Seeing that you are a smart arse, giving incorrect advise, I will tell you that YOU are the stupid one Greg. Enlarging an image in the way you suggest does degrade quality. A medium sized sharp detailed image will become a large blocky (pixellated) image if you go adding pixels that were not already there.

Brian.

On Fri, 11 Nov 2005 21:29:54 +0100, "Greg N." wrote:

DD wrote:

thanx for the good news, Greg, wonder why we buy 6 & 8 mp cameras if we can get along with 1’s and only enlarge the pictures:-) Or is it for the other features?

either you play stupid, or you are. I said you don’t gain any quality by enlarging the picture.

uh uh, you are the stupid one. You said when enlarging the picture you do not gain *or lose* quality. Now suddenly you only said you do not gain? I mean what you said is still there for anybody to see; you said you do NOT lose quality when enlarging:-(

Dave

You can use the Image Size command to enlarge the image, but the quality will decrease.

No. The quality will stay the same. Yo neither gain nor lose anything.

Brian wrote:

Greg N. wrote:

Seeing that you are a smart arse, giving incorrect advise, I will tell you that YOU are the stupid one Greg. Enlarging an image in the way you suggest does degrade quality. A medium sized sharp detailed image will become a large blocky (pixellated) image if you go adding pixels that were not already there.

Sure, no question about that. Let me rephrase my post, so even the home bodies can understand it.

First, we need to define "image quality" with respect to image detail. There are two ways to see it.

1. the amount of detail shown within a given number of pixels.

The amount of detail shown in any, say, 100×100 pixel section of an image will _decrease_ badly if you enlage the image. That’s what you’re referring to, and you’re right.

2. the amount of detail contained in the whole image.

Looking at the image as a whole, the amount of detail it contains will not change if you enlarge the picture. That is what I referred to when I said you’ll neither gain nor lose anything.

You’re with me so far?

My point was, if you want to do picture surgery on a relatively small picture, like removing some people, enlarging it first can be a good idea. It lets you do more precise masking, coping, pasting, stamping, dodging, burning, feathering, blending, and what have you.

When you’re done, you can shrink the picture back to the original dimensions, and you’ll end up with the same image "quality" as you started with.

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

Greg N. wrote:

Brian wrote:

Greg N. wrote:

Seeing that you are a smart arse, giving incorrect advise, I will tell you that YOU are the stupid one Greg. Enlarging an image in the way you suggest does degrade quality. A medium sized sharp detailed image will become a large blocky (pixellated) image if you go adding pixels that were not already there.

Sure, no question about that. Let me rephrase my post, so even the home bodies can understand it.

First, we need to define "image quality" with respect to image detail. There are two ways to see it.

1. the amount of detail shown within a given number of pixels.
The amount of detail shown in any, say, 100×100 pixel section of an image will _decrease_ badly if you enlage the image. That’s what you’re referring to, and you’re right.

2. the amount of detail contained in the whole image.

Looking at the image as a whole, the amount of detail it contains will not change if you enlarge the picture. That is what I referred to when I said you’ll neither gain nor lose anything.

You’re with me so far?

My point was, if you want to do picture surgery on a relatively small picture, like removing some people, enlarging it first can be a good idea. It lets you do more precise masking, coping, pasting, stamping, dodging, burning, feathering, blending, and what have you.
When you’re done, you can shrink the picture back to the original dimensions, and you’ll end up with the same image "quality" as you started with.

Hi again Greg,

ok, now you have explained in a little more detail what you meant, that sounds reasonable. Just one thing there though, there is no need to physically alter the image size. Simply zooming in beyond 100% (to say 200%/300% or more) will have exactly the same effect and you don’t have to resize the image at the beginning or end of processing. I used to do that often when I was manipulating avatars for people in a chat room (in my good old chat room days).

Have a good day Greg,
Brian.

Brian wrote:

Just one thing there though, there is no need to
physically alter the image size. Simply zooming in beyond 100% (to say 200%/300% or more) will have exactly the same effect and you don’t have to resize the image at the beginning or end of processing.

Well, NO! If you work on a zoomed image, your masking will still work on pixel boundaries. But If you first physically double the image dimension, you can indeed cut through the original pixels, so to speak, OK?

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

Thanks for your replies.
So far I have saved as tiff which increased size from 220kB to 2.6 Mb (amazing increase) then I tried a trial version of Genuine Fractals and got it up to 6Mb which I have also saved as a tiff. Image quality is not great but at least I now have some meat to work with.
I think even image enlarging within PS increased size significantly – it was late at night so I was trying a few options.
thanks again
PeterH

"My View" <no spam > wrote in message

I have a 280kB jpeg file that a friend wants me to manipulate (ie remove a couple of people from a group shot).

This was as big a file as I could get.

The file size will reduce even further after I remove parts of the image.
Is there a way to increase the file size to say 2 to 3Mb so I have a bit more meat to deal with?

regards

PeterH

On Fri, 11 Nov 2005 23:01:43 GMT, "My View" <no spam > scribbled:

Thanks for your replies.
So far I have saved as tiff which increased size from 220kB to 2.6 Mb (amazing increase) then I tried a trial version of Genuine Fractals and got it up to 6Mb which I have also saved as a tiff. Image quality is not great but at least I now have some meat to work with.
I think even image enlarging within PS increased size significantly – it was late at night so I was trying a few options.
thanks again

The byte size if an image is utterly irrelevant. Especially since you’re comparing a compressed, lossy format with a lossless format. You have no more ‘meat’ to work with than when you started. All you’ve managed to do is ruin the quality of an image by overly upsizing it.

"My View" <no spam > wrote in message

I have a 280kB jpeg file that a friend wants me to manipulate (ie remove a couple of people from a group shot).

This was as big a file as I could get.

The file size will reduce even further after I remove parts of the image.
Is there a way to increase the file size to say 2 to 3Mb so I have a bit more meat to deal with?

regards

PeterH

On Fri, 11 Nov 2005 22:28:52 +0100, "Greg N." scribbled:

When you’re done, you can shrink the picture back to the original dimensions, and you’ll end up with the same image "quality" as you started with.

Bullshit. Once you’ve ‘added’ pixels to an image by stupidly upsizing it the program won’t magically remove JUST those added pixels if you downsize it when you’re done editing. All you’ll have is a smaller version of a crappy picture you ruined earlier in the process.

Voivod wrote:

Bullshit. Once you’ve ‘added’ pixels to an image by stupidly upsizing it the program won’t magically remove JUST those added pixels if you downsize it when you’re done editing. All you’ll have is a smaller version of a crappy picture you ruined earlier in the process.

Well, if you’re stupid enough to enlarge it by an non-integer factor and then downsize it by another queer divider, yes, you may ruin the image thoroughly.

But if you double the dimensions, then halve them, you’ll end up with the same picture.

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

Greg N. wrote:

Voivod wrote:

Bullshit. Once you’ve ‘added’ pixels to an image by stupidly upsizing it the program won’t magically remove JUST those added pixels if you downsize it when you’re done editing. All you’ll have is a smaller version of a crappy picture you ruined earlier in the process.

Well, if you’re stupid enough to enlarge it by an non-integer factor and then downsize it by another queer divider, yes, you may ruin the image thoroughly.

But if you double the dimensions, then halve them, you’ll end up with the same picture.

I forgot to mention:

And of course, you’ll need to chose the right Interpolation option, namely "Nearest Neighbor". It basically means, there will be no interpolation.

When you double the image dimensions using "nearest neighbor", it will take each pixel and turn it into a square of four identical pixels. When you scale down to 50% later, it will turn each block of 4 pixels into one pixel again.

So while you’re manipulating the picture, you have 4 times more pixels to work with. It does not mean the image has more details, but your marquees (and consequently, the details you create in your manipulations) can be more precise.

And after you scale down ithe image (again by a factor of 2 and by using "nearest neighbor" interpolation, you’ll end up with the initial picture quality unchanged.

—
Gregor’s Motorradreisen:
http://hothaus.de/greg-tour/

"Greg N." wrote in message

No. The quality will stay the same. Yo neither gain nor lose anything.

If the viewer moves far enough away.

"DD" wrote in message

On Fri, 11 Nov 2005 21:29:54 +0100, "Greg N."

either you play stupid, or you are. I said you don’t gain any quality by enlarging the picture.

uh uh, you are the stupid one.

Hey. This is going nowhere. Why we don’t just bash Beemers instead.