Chris Lilley 🏴󠁧󠁢󠁳󠁣󠁴󠁿Jun 24

The Third Edition of Portable Network Graphics (PNG) today became a W3C Standard.

It adds support for High Dynamic Range (HDR), and adds Animated PNG to the official standard.

https://www.w3.org/TR/png-3/

Portable Network Graphics (PNG) Specification (Third Edition)

This document describes PNG (Portable Network Graphics), an extensible file format for the lossless, portable, well-compressed storage of static and animated raster images. PNG provides a patent-free replacement for GIF and can also replace many common uses of TIFF. Indexed-color, greyscale, and truecolor images are supported, plus an optional alpha channel. Sample depths range from 1 to 16 bits.

Show threadGraham Sutherland / PolynomialJun 24
@svgeesus nice! looking forward to being able to store PQ quantised images losslessly this way ^^
Show threadChris Lilley 🏴󠁧󠁢󠁳󠁣󠁴󠁿

@gsuberland yes, both BT.2100 PQ and P3D65 PQ are supported

We also support Content Light Level (MaxFALL, MaxCLL) and Mastering Display Color Volume.

Jun 24 at 2:08pmWeb
Show threadGraham Sutherland / PolynomialJun 24
@svgeesus is P3D65 PQ a different transfer curve? I always thought it was mathematically identical to the BT.2100 PQ curve, although admittedly I never looked at the P3 stuff very hard.
Show threadChris Lilley 🏴󠁧󠁢󠁳󠁣󠁴󠁿Jun 24
@gsuberland Same curve, different primaries
Show threadGraham Sutherland / PolynomialJun 24
@svgeesus ah, yeah, makes sense.
Show threadChris Lilley 🏴󠁧󠁢󠁳󠁣󠁴󠁿Jun 24

@gsuberland I blogged about that, today

https://svgees.us/blog/cICP.html#introducing-cicp

cICP in PNG, explained • Chris Lilley