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Discarding jpegs due to multiple edits?
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Apr 4, 2019 23:45:19   #
Insp Gadget
 
Dragonophile wrote:
PLEASE, I DO NOT WANT A RAW VRS JPEG DISCUSSION. I have seen enough of those. You don't like jpeg, fine. But this is NOT the thread to explain to me and others why we should avoid jpeg.

My question is about real world experiences of those WHO DO USE JPEG in the area of degradation. I am asking if jpeg users have ever had to discard formerly good photos because they saw too much degradation after multiple edits. If so, how many edits? Were they saved at highest quality or compressed more each time?
PLEASE, I DO NOT WANT A RAW VRS JPEG DISCUSSION. I... (show quote)




Your question has been answered. Don't ever save over the original image. Always save a copy after editing. You'll lose nothing that way.

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Apr 5, 2019 00:36:05   #
Blenheim Orange (a regular here)
 
AndyH wrote:
Here's a test, so you can see for yourself. It's a simple JPEG, opened and lightly edited (Exposure, color, and clarity) three times using Windows photos, and saved over itself. The original is SOOC, the second image has been resaved three times. Download and compare. If the IQ is satisfactory for you, you don't need to worry about editing in JPEG format. If you don't like it, well, you now know how to avoid it.

Focus isn't perfect in the either one. Lossy elements are in the darker areas and the details, as in the grass. These are small images, so
you do need to zoom in to see the difference. In my judgement it would be visible, although not a complete deal killer, at about 8x10 or larger.

You be the judge. Remember, this is only the third generation. Under no circumstances do you want to go more than about double that.

Andy
Here's a test, so you can see for yourself. It's a... (show quote)


Both of those files are 318 kb. I did one save at a very moderate compression factor, the one I routinely use for JPEGs that I post online, and that dropped the file size to 62 kb. At the highest quality setting, the file size still dropped to 225 kb. Hard to imagine how three saves could be done with no change to the file size whatsoever.

Mike

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Apr 5, 2019 01:17:51   #
nikonuser750
 
Dragonophile wrote:
PLEASE, I DO NOT WANT A RAW VRS JPEG DISCUSSION. I have seen enough of those. You don't like jpeg, fine. But this is NOT the thread to explain to me and others why we should avoid jpeg.

My question is about real world experiences of those WHO DO USE JPEG in the area of degradation. I am asking if jpeg users have ever had to discard formerly good photos because they saw too much degradation after multiple edits. If so, how many edits? Were they saved at highest quality or compressed more each time?
PLEASE, I DO NOT WANT A RAW VRS JPEG DISCUSSION. I... (show quote)


Edit a jpeg repeatedly and you will see degredarion. I hope that answers your question.

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Apr 5, 2019 08:30:59   #
dsmeltz (a regular here)
 
Just a thought. A habit some people have from other computer programs that is NOT useful when directly editing JPEGs. Saving your edits every five minutes. If you are editing a jpeg in an app that overwrites your file and you save frequently you will start to see real deterioration fairly quickly. If you can hold off and just do it once, you not see noticeable deterioration.

One of the advantages of non-destructive editors (most of the major editors use this path now) is the ability to save your editing instructions frequently without overwriting the file as you would with a word processor or spreadsheet.

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Apr 5, 2019 08:55:29   #
AndyH (a regular here)
 
Blenheim Orange wrote:
Both of those files are 318 kb. I did one save at a very moderate compression factor, the one I routinely use for JPEGs that I post online, and that dropped the file size to 62 kb. At the highest quality setting, the file size still dropped to 225 kb. Hard to imagine how three saves could be done with no change to the file size whatsoever.

Mike


Small files to begin with, maybe?

So I did it again with fine JPEGs. Original image is 2.53 MB on my computer. Second shot, the flipped image, is 2.02 MB. Very minor edits for exposure, clarity, and flipping the image.

You be the judge, but be sure to download the original images to look.

Andy
Original version unedited
Original version unedited...
(Download)
After 3 saves
After 3 saves...
(Download)

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Apr 5, 2019 08:57:19   #
dsmeltz (a regular here)
 
AndyH wrote:
Small files to begin with, maybe?

So I did it again with fine JPEGs. Original image is 2.53 MB on my computer. Second shot, the flipped image, is 2.02 MB. Very minor edits for exposure, clarity, and flipping the image.

You be the judge, but be sure to download the original images to look.

Andy


You should not see significant deterioration in a single save.

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Apr 5, 2019 09:53:23   #
AndyH (a regular here)
 
dsmeltz wrote:
You should not see significant deterioration in a single save.


True. This second cut was three saves and approximately a 20% reduction in file size, from 2.52 to 2.02 MB. Each save involved different changes, although I don't know what difference that makes. One was in exposure, one in clarity, and one was the flip.

This was just an ordinary JPEG snapshot that my wife took of me with her old Canon Powershot. I can see data loss in the ocean and sky textures, and some on my clothing as well, but that's just me.

In any event, I thought this would provide a good illustration of why you need to shift back and forth into a lossless format if you're doing multiple edits working off of a JPEG original. If it's visible in spots, and you've lost 20% of your image data in just three saves, why chance it?

Or, as I do, work off the RAW image and save in JPEG format.

Andy

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Apr 5, 2019 11:46:09   #
RV
 
All these so-called great photographers on here who imply their images are so good they never have to edit their images.............. My response.....Ansel Adams.

Have a Nice Day!

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Apr 5, 2019 11:55:22   #
Blurryeyed (a regular here)
 
Dragonophile wrote:
I have read/been told that every time you edit a jpeg file you lose some information. I am not questioning this fact. However, some people imply this is a problem; others say no big deal. When I save my jpegs, I do so at the highest quality the program allows.

My question: are there Hoggers who have discarded formerly good jpeg pictures because they became degraded over time with multiple edits? I am curious if this is a real world problem or more a theoretical concern. If you have lost pictures, can you estimate the number of discrete editing sessions they underwent.

I assume the degradation becomes more noticeable as the print size increases, correct?
I have read/been told that every time you edit a j... (show quote)


I always used to rename my jpeg files so as to always have the original to go back to, you can't undo saved edits on a jpeg file and sometimes you realize that you have over baked that image and have no remedy. Now I only shoot RAW and with my files that come off of my Canon cameras all I have to do is throw away the changes that are stored in a separate file, for some reason Photoshop saves the changes to my Fuji files to the RAW image however those images can be reset manually.

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Apr 5, 2019 12:07:33   #
davyboy
 
AndyH wrote:
Here's a test, so you can see for yourself. It's a simple JPEG, opened and lightly edited (Exposure, color, and clarity) three times using Windows photos, and saved over itself. The original is SOOC, the second image has been resaved three times. Download and compare. If the IQ is satisfactory for you, you don't need to worry about editing in JPEG format. If you don't like it, well, you now know how to avoid it.

Focus isn't perfect in the either one. Lossy elements are in the darker areas and the details, as in the grass. These are small images, so
you do need to zoom in to see the difference. In my judgement it would be visible, although not a complete deal killer, at about 8x10 or larger.

You be the judge. Remember, this is only the third generation. Under no circumstances do you want to go more than about double that.

Andy
Here's a test, so you can see for yourself. It's a... (show quote)


Sorry can’t see any difference

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Apr 5, 2019 12:10:39   #
davyboy
 
nikonuser750 wrote:
Edit a jpeg repeatedly and you will see degredarion. I hope that answers your question.


Wish I could see it

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Apr 5, 2019 12:38:40   #
AndyH (a regular here)
 
davyboy wrote:
Sorry can’t see any difference


This is why we use different shooting methods and formats to achieve different goals. I agree that it's barely apparent on a computer screen at this resolution, but try printing it 16x20 and you'll see the difference. If you're not going to do that, and not "save over" more than three times, you'll be fine.

I have no problem with people shooting native JPEG. It's certainly faster to process and the IQ is far better than it used to be.

I think the summary of this thread would go something like this:

1) If you're going to edit in native JPEG format (without going back to the original version each time you edit), either do repeated "save as" saves, or only do one set of edits at a time.

2) If you're starting with JPEG and want to do a longer series of edits, it's best to convert the working copy to TIFF, PNG, PSD, or some other lossless format, and make the edits within that format - using JPEG as an export only.

3) If you ignore those two options you'll eventually run out of IQ, depending on your intended use. I see discernible data loss after 3-5 saves in many images, others may differ.

No complaints here that you have to shoot in RAW to be a real photographer. It affords, in my opinion, MUCH greater control over colors, exposure, saturation, and white balance, but if you don't need it, why put in the time?

Andy

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Apr 5, 2019 20:51:21   #
burkphoto (a regular here)
 
nikonuser750 wrote:
Edit a jpeg repeatedly and you will see degredarion. I hope that answers your question.


Is degredarion an alien puppy or something? (Sorry, funny typo there!)

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Apr 5, 2019 21:03:35   #
burkphoto (a regular here)
 
AndyH wrote:
This is why we use different shooting methods and formats to achieve different goals. I agree that it's barely apparent on a computer screen at this resolution, but try printing it 16x20 and you'll see the difference. If you're not going to do that, and not "save over" more than three times, you'll be fine.

I have no problem with people shooting native JPEG. It's certainly faster to process and the IQ is far better than it used to be.

I think the summary of this thread would go something like this:

1) If you're going to edit in native JPEG format (without going back to the original version each time you edit), either do repeated "save as" saves, or only do one set of edits at a time.

2) If you're starting with JPEG and want to do a longer series of edits, it's best to convert the working copy to TIFF, PNG, PSD, or some other lossless format, and make the edits within that format - using JPEG as an export only.

3) If you ignore those two options you'll eventually run out of IQ, depending on your intended use. I see discernible data loss after 3-5 saves in many images, others may differ.

No complaints here that you have to shoot in RAW to be a real photographer. It affords, in my opinion, MUCH greater control over colors, exposure, saturation, and white balance, but if you don't need it, why put in the time?

Andy
This is why we use different shooting methods and ... (show quote)


Good stuff, Andy.

Here’s a safe workflow:

> Open 8-bit JPEG in sRGB
> Convert to and save as a 16 bit TIFF or PSD
> Convert profile from sRGB to ProPhoto RGB
> Edit and save as needed
> Convert profile from ProPhoto to sRGB
> Convert to 8-bits
> Save as a high quality full size JPEG in sRGB

This is a lab-proven method for adjusting JPEGs that need more than slight adjustment. It isn’t a miracle worker, but it does minimize banding, out-of-gamut colors, JPEG compression artifacts, etc. It’s especially good for files that will be retouched, layered, and composited.

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Apr 5, 2019 21:09:02   #
AndyH (a regular here)
 
burkphoto wrote:
Good stuff, Andy.

Here’s a safe workflow:

> Open 8-bit JPEG in sRGB
> Convert to and save as a 16 bit TIFF or PSD
> Convert profile from sRGB to ProPhoto RGB
> Edit and save as needed
> Convert profile from ProPhoto to sRGB
> Convert to 8-bits
> Save as a high quality full size JPEG in sRGB

This is a lab-proven method for adjusting JPEGs that need more than slight adjustment. It isn’t a miracle worker, but it does minimize banding, out-of-gamut colors, JPEG compression artifacts, etc. It’s especially good for files that will be retouched, layered, and composited.
Good stuff, Andy. br br Here’s a safe workflow: ... (show quote)




Good advice from a real pro.

Andy

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