User talk:CanvasK/Archive 3: Difference between revisions

::"Though there is some advantage to converting jpegs to pngs when downscaled for articles, as this won't produce further compression artifacts", hypothetically yes, in practice it barely matters. JPG's artifacts are almost always in 8x8 pixel blocks (sometimes 16x16 but much less often). The article image was scaled down to 500x250 px with the source being 4000x2000 px. This is an 1/8x scale, meaning the source artifacts would be scaled down to single pixels and thus have little to no influence on the discrete cosine transform (DCT, the part of JPG that causes the artifacts) when resaving. Even at 1/4x scale any resulting artifacts would be unnoticeable except to someone like me who scrutinizes this kind of stuff, but even then that kind of person would directly open the image to see it raw instead of an inferior copy. 1/4x is pretty common on the wiki with most game screenshots being 1280x720 and scaling down to a reasonable 300xWhatever size.

::In short, better to keep JPGs as JPGs and PNGs as PNGs. It is extra disk space for the wiki, extra bandwidth for the wiki, probably longer load times (because of the larger file size and the more convoluted rendering sequence), and extra disk space for whomever downloads the image for whatever they need—which will probably be turned in to another lossy format, so double artifacts. If the source is a video then artifacts are inevitable and a PNG is preferred to prevent double artifacting, though the highest quality available should be used if possible. --[[User:CanvasK|CanvasK]] ([[User talk:CanvasK|talk]]) 16:15, June 14, 2022 (EDT)