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A comment on Shannon’s Source Coding Theorem (Foundations of Information Theory: Part 3). Parent comment

Re:Shannon’s Source Coding Theorem (Foundations of Informati... by CorrectHorseBat on Sunday June 18, 2023 @01:36PM (#36382378)
JPEG XL supports reversible JPEGs transcoding in ~20% less space, which wouldn't be possible if JPEG was very close to the Shannon entropy limit.
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Re:Shannon’s Source Coding Theorem (Foundations of Informati... by Panzer04 on Sunday June 18, 2023 @08:13PM (#36385861)
JPEG is lossy though - I'm pretty sure these theorems only really apply to lossless compression, because if you allow lossy compression you can do all kinds of things to different t types of data (pictures being the classic case of permitting pretty lossy compression without much noticeable quality degradation)
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Re:Shannon’s Source Coding Theorem (Foundations of Informati... by CorrectHorseBat on Sunday June 18, 2023 @11:14PM (#36386936)
Maybe I wasn't clear enough: JPEG -> JPEG XL -> JPEG is not lossy, you get exactly the same bits back, but the JPEG XL file is 20% smaller.
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Re:Shannon’s Source Coding Theorem (Foundations of Informati... by Panzer04 on Monday June 19, 2023 @10:27PM (#36399009)
Oh, very interesting. I'll have to look into it.
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