• B0rax@feddit.org
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    4 个月前

    JPEG for graphics like screenshots is not very efficient. For stuff like that, png is simply superior. (But not with compression 0)

    PNG is not good for photos though.

    • tetris11@lemmy.ml
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      4 个月前

      why though? The graphics represented in the screen are already squashed and scaled, so you wouldn’t be preserving their quality in any case. If you’re worried about text, JPEG should still be able to handle it under high quality settings

      • B0rax@feddit.org
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        4 个月前

        We can ask the same the other way around: why do you want to use jpg if it results in a bigger size and worse quality than png?

        • tetris11@lemmy.ml
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          4 个月前

          But that’s patently untrue: take this 10 MB example TIFF file as an example.

          • PNG Compression, max compress (=quality 9):

            convert file_example_TIFF_10MB.tiff -quality 9 test.png
            
          • JPG Encoding, 99% quality (=quality 99):

            convert file_example_TIFF_10MB.tiff -quality 99 test.jpg
            

          Final file size comparison:

          9.7M Sep  5 13:21 file_example_TIFF_10MB.tiff
          1.7M Sep  5 13:22 test.jpg
          2.5M Sep  5 13:22 test.png
          

          PNG is significantly larger, and difference in quality between them is negligible

          • B0rax@feddit.org
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            4 个月前

            Dude. Did you even read what I wrote? PNG is bad for photos. Your example is a photo. Go ahead and try the same with a screenshot with text and menus showing.

          • ms.lane@lemmy.world
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            4 个月前

            png - jpg

            156K Sep  5 23:06 Screenshot_20240905_230459.jpg
            137K Sep  5 23:05 Screenshot_20240905_230459.png
            

            jpg with 80% compression, via krita.

            As B0rax said, for screenshots, png is better - it can represent line graphics and text more efficiently.

            • tetris11@lemmy.ml
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              4 个月前

              Thanks for this. Still, I would be curious to see this for a 4K level image. Also I wonder if your screenshot tool did a bitmap copy of the screen or intrinsically converted it to PNG first before pasting it into your paint editor.