As any conscientious uploader knows, third-party edits that significantly alter the image are against the uploading rules, but some of these kinds of edits may be permitted if the original can't be found. However, the problem I'm having here is basically the opposite.
I want to upload a collection of 1koma used for the loading screen of the mobile game Alternative Girls. They're supposed to be images with a landscape orientation, but their aspect ratios were changed to 512x512 sometime before they were added to the game files (the cards are also saved as square images). They are only seen with the correct aspect ratio when playing the game.
The least destructive edit to correct the aspect ratio is to increase the width without changing the height. I determined that to correct the aspect ratio while keeping the height at 512 pixels, the width would need to be increased to 722 pixels. I used Python's PIL library to resize the image with different filters and found that the bilinear filter results in an appearance closest to how it's rendered in-game (I didn't just trust my eyes; I also checked the pixel differences in GIMP).
Here is the unmodified image:
asset #22583460
Here is the image after correcting the aspect ratio with a bilinear filter:
asset #22584593
And here is an in-game screenshot taken with BlueStacks with a custom screen resolution set to keep the comic at its original height:
asset #22584826
At least some of these comics can be found online, but they seem to be taken from game screenshots of various sizes. You can tell because they include the frame and title, which are created from other game assets and are not part of the comic image itself. These screenshots should also be based on the 512x512 images, but the comics would be altered further because they are scaled in both directions instead of just one. Also, the screenshots tend to be blurrier and sometimes even have incorrect aspect ratios (about 655 pixels in width instead of 722). I believe in this specific case, uploading the asset after increasing just the width would be closer in spirit to the uploading rules than uploading a game screenshot in which more than just the width is changed.
So what do I do here? Should I post the corrected image? Should I post only the unmodified image and tag it with bad aspect ratio? Should I upload both and make the unmodified one the parent? Or is there nothing I can do?
And if it's acceptable to post the modified image in this case, would tagging it upscaled be sufficient, or would we need a new metatag for this (something like upscaled width or changed aspect ratio)?