Display Pixel Format Differences Between PNGs

[MrCowKing]

While PNG is a lossless format, there are multiple pixel formats that can be used to reduce the size of the image with a minimal loss in quality. The duplicate filter, as of v566, does not display the pixel format differences between PNG files; it will only display the size difference. Some images are compressed well and the only indication that the pixel format is different is one will have a (sometimes hard to notice) paletted dither pattern.

[bbappserver]

I think I've seen this problem manifest, since you can have two different sized pngs that look the same. But the duplicate filter is for detecting perceptual dups. In this case the perceptual answer is "they are same quality duplicates". The policy for which file should be kept in this case is another mater. The duplicate filter isn't really fleshed out well enough to do much beyond detecting a duplicate, and is really much beter at detecting alternate sets, although if you've got duplicate alternates lord help you.

[Mengmoshu]

@bbappserver This is about displaying relevant metadata and file format information, something that the duplicate filter UI already does for things like color profiles and JPEG compression rates. This request is very much about providing users with the sort of information that lets them make those policy decisions, it isn't about duplicate detection doing anything with that pixel format information. You can tell this by the use of words like "display" and "indication".