File Question about Elements Digital Software

[jadin]

I already did. Oops fixed it.

Wrong file. 4212 please.

 

[Ysarex]

But even if you are right, which you seem to be before I test myself - this is still true:

"Compression from the JPEG to the tiff has the original loss saved already. Nothing can be done about that."

Continuing to edit and have "further issues" is just extended results of the original compression. There's no NEW compression being done, so for Marc's question, as long as he gets out of JPEG right away (or skips JPEG completely if he has RAW files), then no, there is no continued degradation just from using the software.

Yes there is. Just because it's the original compression grid biting you from the original camera save doesn't mean you're not experiencing degradation in the image from using the software editing tools. In fact this is the more severe and damaging degradation.

At least not in the sense people are referring to when they ask about lossy compression.

People don't understand. They think they can convert a JPEG to a TIFF and not experience further degradation due to the JPEG compression. They are mistaken.

 

[Ysarex]

Wrong file. 4212 please.

fixed it.

Dropbox

www.dropbox.com

 

[jadin]

Yes there is. Just because it's the original compression grid biting you from the original camera save doesn't mean you're not experiencing degradation in the image from using the software editing tools. In fact this is the more severe and damaging degradation.

People don't understand. They think they can convert a JPEG to a TIFF and not experience further degradation due to the JPEG compression. They are mistaken.

That's fine. But if the only file they have access to is a JPEG, then there's nothing left for them to do but get out of JPEG as soon as possible. It's that or not edit the file ever again. So again, just for people like Marc, I think the original answers are best. There is no additional degradation due to further compression.

And I'm pretty sure that's all that anyone like Marc cares about. Although he can certainly correct me if I'm putting words in his mouth.

 

[Ysarex]

That's fine. But if the only file they have access to is a JPEG, then there's nothing left for them to do but get out of JPEG as soon as possible. It's that or not edit the file ever again. So again, just for people like Marc, I think the original answers are best. There is no additional degradation due to further compression.

The question wasn't about further compression. This was the question: "then when you are using the various tools in say Elements, does your picture continue to lose detail as you use the program?" And the answer is yes.

And I'm pretty sure that's all that anyone like Marc cares about. Although he can certainly correct me if I'm putting words in his mouth.

 

[jadin]

I'm still not convinced.

Are the artifacts more noticeable? Sure.

But is there more degradation? Like at all? Not that I'm seeing.

The same artifacts are in both. No difference.

These are the changes I made if you are curious.

But no matter what, I'm done with this. What a waste of time.

 

[Ysarex]

I'm still not convinced.

Are the artifacts more noticeable? Sure.

That is degradation. JPEG works by hiding the compression grid. Edit changes to tone and color after the original lossy compression make the grid visible in the form of mottling noise and banding in the image.

But is there more degradation?

If you didn't see it before and you do see it now as you say, "more noticeable" then of course.

Like at all? Not that I'm seeing.

The same artifacts are in both. No difference.

Big difference: JPEG has effectively rendered the artifacts nearly invisible. Editing makes them more visible -- that's degradation.

These are the changes I made if you are curious.

The edit changes you made have degraded the image by adding mottling artifacts to the sky. It is clearly visible. Continued editing of tone/color will cause continued degradation.

But no matter what, I'm done with this. What a waste of time.

At least you learned something ;-)

 

[jadin]

At least you learned something ;-)

Nope.

 

[Marc Hildebrant]

This discussion has been very useful to me, and I have learned quite a bit from the deep technical dive.

Marc

 

[RacePhoto]

This discussion has been very useful to me, and I have learned quite a bit from the deep technical dive.

Marc

Me too. Always room to learn more and enjoying that.

"JPEG Compression and recompression cause loss."

Ysarex​

There's the shortest version of what happens and the cause.

The original question asked, "while editing" I took that literally as while editing.

ps I shoot JPG, I edit, everything I save is second generation, because I opened it once and saved it. Anything someone does from RAW is first generation JPG compression. It's that simple.

 

[Ysarex]

Me too. Always room to learn more and enjoying that.

"JPEG Compression and recompression cause loss."

Yes, I said the same but additionally noted that recompression causes minimal harm.

Ysarex​

There's the shortest version of what happens and the cause.

The original question asked, "while editing" I took that literally as while editing.

And you were wrong when you answered "NO" to the OP's original question. You are wrong saying this: "Editing doesn't destroy any data."
While editing, changes to the tone/color of the image will interact with the JPEG compression grid embedded in the image and degrade the image -- right then and there while editing. And it's worth noting that this degradation is often more substantial and more harmful than the result of recompression.

ps I shoot JPG, I edit, everything I save is second generation, because I opened it once and saved it. Anything someone does from RAW is first generation JPG compression. It's that simple.

 

[RacePhoto]

Yes, I said the same but additionally noted that recompression causes minimal harm.

And you were wrong when you answered "NO" to the OP's original question. You are wrong saying this: "Editing doesn't destroy any data."
While editing, changes to the tone/color of the image will interact with the JPEG compression grid embedded in the image and degrade the image -- right then and there while editing. And it's worth noting that this degradation is often more substantial and more harmful than the result of recompression.

"while editing"

So you mean, "while editing" if you have a RAW image, you are also degrading the image, because you are editing it, and by saving it, you further degrade it? At some point an image has to be saved at least one time.

No I don't understand the JPEG compression grid.

Assuming someone has a RAW image and opens it and edits for three hours, vs someone who opens an image and edits for 5 minutes, and in both cases, saves the image only once. You are telling me that the one that was edited for a longer time, is different from one that is edited in 5 minutes?

Nope I don't understand. You're right.

 

[Ysarex]

"while editing"

So you mean, "while editing" if you have a RAW image, you are also degrading the image, because you are editing it, and by saving it, you further degrade it?

No, not raw data. Specifically an image that has undergone JPEG compression -- for example a camera generated JPEG.

At some point an image has to be saved at least one time.

No I don't understand the JPEG compression grid.

You need to -- that's the source of image degradation that occurs "while editing."
JPEG works by placing a grid of 8x8 pixels over the entire image. Photographic data is generally pretty dense such that in one of those grid cells of 64 pixels odds are all or most of the pixels are unique. To get the levels of compression that JPEG achieves redundancy is needed. So instead of 64 unique pixels in an 8x8 cell we need to have for example only 36 unique pixels with a lot of the remaining 28 pixels the same. For more compression we need less unique pixels and more pixels the same. JPEG goes into those grid cells and starts changing pixels making more and more pixels the same in order to achieve more compression. That 8x8 pixel grid is the structure that JPEG uses to achieve high compression rates. That grid and the changes made using it become a permanent part of the image. When you start editing, that grid is there in the image. If you convert the image to a TIFF file before editing, that grid is still there in the image. If you then make changes to the tone/color of the image your changes "while editing" -- as you make them -- interact with the embedded compression grid and degrade the image right then and there "while editing."

There is no compression grid embedded in raw data. This is strictly a JPEG issue.

Assuming someone has a RAW image and opens it and edits for three hours, vs someone who opens an image and edits for 5 minutes, and in both cases, saves the image only once. You are telling me that the one that was edited for a longer time, is different from one that is edited in 5 minutes?

Nope, never said that. From the OP's original question: "If the JPEG file is a "loss type", then when you are using the various tools in say Elements, does your picture continue to lose detail as you use the program?" This is a uniquely JPEG problem.

Nope I don't understand. You're right.

 

[Ysarex]

"while editing"

So you mean, "while editing" if you have a RAW image, you are also degrading the image, because you are editing it, and by saving it, you further degrade it? At some point an image has to be saved at least one time.

No I don't understand the JPEG compression grid.

Assuming someone has a RAW image and opens it and edits for three hours, vs someone who opens an image and edits for 5 minutes, and in both cases, saves the image only once. You are telling me that the one that was edited for a longer time, is different from one that is edited in 5 minutes?

Nope I don't understand. You're right.

Download these two files:

Dropbox

www.dropbox.com

Dropbox

www.dropbox.com

Open them and compare the sky between them. Zoom in to 100% and more while comparing the sky between these two files. There is a mottling degradation apparent in the sky of the edited JPEG. That degradation was produced "while editing" as the edit changes to darken, increase saturation and change the hue of the sky interacted with the JPEG compression grid. If you zoom in enough you can make out compression grid cells becoming visible.

Here's the original camera JPEG: _DSC4212.JPG

 

[Marc Hildebrant]

Ysarex,

Thanks for the info on the JPEG compression grid.

Marc