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by bawolff 313 days ago
Doesn't PNG have progressive decoding? I.e. adam7 algorithm
2 comments
layer8 313 days ago
It does, using Adam7: https://en.wikipedia.org/wiki/Adam7_algorithm

The recently released PNG 3 also supports HDR and animations: https://www.w3.org/TR/png-3/

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bawolff 313 days ago
> The recently released PNG 3 also supports HDR and animations: https://www.w3.org/TR/png-3/

APNG isn't recent so much as the specs were merged together. APNG will be 21 years old in a few weeks.

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layer8 313 days ago
True, but https://news.ycombinator.com/item?id=44802079 presumably holds the opinion that APNG != PNG, so I mentioned PNG 3 to counteract that. Animated PNGs being officially PNG is recent.
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duskwuff 313 days ago
Adam7 is interlacing, not progressive decoding (i.e. it cannot be used to selectively decode a part of the image). It also interacts extremely poorly with compression; there is no good reason to ever use it.
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