Gui: Add default JPEG save quality

[vernzimm]

Set jpg screenshot capture to 100% quality vs qimage defaulting to -1
Save Picture/Export PDF quality issues

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[adrianinsaval]

how much does this affect the generated file size?

[chennes]

Thanks for the PR, @vernzimm -- the code itself doesn't quite work (C++ doesn't permit named arguments like that), but I understand what you're driving at. I did a quick test, @adrianinsaval, and the two attached JPEGs are 122kb (pre-PR) and 347kb (post-PR). So in this case it's nearly a 3x size increase, for a pretty minimal quality increase. @vernzimm can you attach a test case that better illustrates what you are trying to improve?

[freecadci]

for feature branch PR_7737. Pipeline 688941178 was triggered at 7944108. All CI branches and pipelines.

[vernzimm]

Hello everyone, I appreciate all of the feedback, and I apologize if this is wasting anyone's time.

@adrianinsaval @chennes here is the discussion about this and a few other things
Save Picture/Export PDF quality issues

Basically, I'm considering 300KB to be negligible. I would guess that the vast majority of cases do not have a consideration of file size at that level, or if they do, they can downgrade. Currently I can not upgrade (I have begun exporting to .png and then converting to .jpg). As you know, many programs do include a quality option for .jpg export. I do not possess the ability to implement that :(

The compromise may be, due to the very nature of the .jpg compression, we go with something like 90%. It is 145KB with very little noticeable artifacts.

Text is also a major issue, but 90% seems to keep that well defined.

@chennes about the code, I was working from QT docs that someone looked up for me. I think I was reading the doc formatting wrong :). I'm guessing it would be simply
image.save(&buffer, "JPG", 100);?

[vernzimm]

@adrianinsaval @chennes I was just looking at the "checks" that failed. They did fail for that code. Is there a way I can run those before sending PR?

[chennes]

Yes, this is the correct code:

image.save(&buffer, "JPG", 100);

(or, as you suggest, use 90 instead of 100). Do you know how to edit your previous commit and force-push the change? If not, you can just add a new commit with the fix and I will squash when merging.

[vernzimm]

Correct previous attempt and change to 90% from 100%

[vernzimm]

@chennes I think I got it? Rebase from master, edit the file, and commit that into vernzimm-patch-1 branch. It's not really editing the original pull request though, in which case no, I don't know 😆

[freecadci]

for feature branch PR_7737. Pipeline 689248893 was triggered at 3952f73. All CI branches and pipelines.

[freecadci]

for feature branch PR_7737. Pipeline 689252408 was triggered at 549398b. All CI branches and pipelines.

[chennes]

It's not necessary for you to do anything else, I am happy to squash and merge on my end, but if you are interested in learning, the operation you want to do is an "interactive rebase" which you will use to "squash" the commits and then "force push" the resulting single commit, overwriting the original commits. On the command line, it goes like this (in the case of two commits being combined into one):

git rebase -i HEAD~2

This will pop up an editor window that lists your two commits, looking like this:

pick 3952f7393c Update SoFCOffscreenRenderer.cpp
pick 549398b340 Add default quality to JPG export 

There are some instructions in a comment section below, but what you want to do is change the second pick to squash (or just s):

pick 3952f7393c Update SoFCOffscreenRenderer.cpp
s 549398b340 Add default quality to JPG export 

Save the file and close it. Another editor will pop up offering to let you create a commit message for the new, combined commit. Set it to whatever you want (probably just the commit message you wrote for the first commit). Save and close. Finally, you have to overwrite the commits in your branch to just consist of the new commit:

git push -f

If you refresh the GitHub page for your PR, you'll see that there is now only the single commit.

[donovaly]

Can this be backported for FC 0.20.2? To me this seems like it improves the situation for average users without adding new functionality. If you agree, it fulfills the criterion for backporting.

[chennes]

Sure, should just be a simple cherry pick. I'll take care of it later today.

[donovaly]

Thanks, I backported it now.