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A new PNG spec

(www.programmax.net)
614 points bluedel | 2 comments | 24 Jun 25 13:01 UTC | HN request time: 0.477s | source
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razorfen ◴[25 Jun 25 16:10 UTC] No.44378903[source]▶
Can anyone explain how they maintain backwards compatibility on formats like this when adding features? I assume there are byte ranges managed in the format, but with things like compression, wouldn’t compressed images be unrenderable on clients that don’t support it? I suppose it would behoove servers to serve based on what the client would support.
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1. gmueckl ◴[25 Jun 25 16:27 UTC] No.44379105[source]▶
In mynunderstanding, the actual image data encoding isn't altered in this update. It only introduces an extended color space definition for the encoded data.

PNG is a highly structured file format internally. It borrows design ideas from formats like EA's Interchange File Format in that it contains lists of chunks with fixed headers encoding chunk type amd length. Decoders are expected to parse them and ignore chunk types they do not support.

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2. joquarky ◴[25 Jun 25 16:53 UTC] No.44379423[source]▶
The Amiga was quite a platform. Glad to know that it had some long term influence.