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A new PNG spec

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625 points bluedel | 1 comments | 24 Jun 25 13:01 UTC | HN request time: 0.4s | source
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LegionMammal978 ◴[25 Jun 25 05:06 UTC] No.44373779[source]▶
Reading the linked blog post on the new cICP chunk type [0], it looks like the "proper HDR support" isn't something that you couldn't already do with an embedded ICC profile, but instead a much-abbreviated form of the colorspace information suitable for small image files.

[0] https://svgees.us/blog/cICP.html

replies(3): >>44379489 #>>44380668 #>>44385910 #
1. cormorant ◴[25 Jun 25 16:59 UTC] No.44379489[source]▶
"common but not representable RGB spaces like Adobe 1998 RGB or ProPhoto RGB cannot use CICP and have to be identified with ICC profiles instead."

cICP is 16 bytes for identifying one out of a "list of known spaces" but they chose not to include a couple of the most common ones. Off to a great start...

I wonder if it's some kind of legal issue with Adobe. That would also explain why EXIF / DCF refer to Adobe RGB only by the euphemism "optional color space" or "option file". [1]

[1] https://en.wikipedia.org/wiki/Design_rule_for_Camera_File_sy...