Rod

_Should_ jpeg xl be allowed under the jpg graphic type? :)

> Does Jpeg XL deprecate webp? https://caniuse.com/jpegxl makes support look a touch gloomy so maybe not quite yet. Still, if we can claim jpegxl _should_ work then maybe its not...

> only finalized in Dec 2020 Oh good catch, I somehow thought it'd been done a bit longer. Nice.

The biggest catch I'm currently aware of with bitmaps is what happens when compositing a bitmap that isn't sRGB. But maybe we do two versions and in the first version...

We reference https://www.w3.org/TR/compositing-1/ for compositing. https://www.w3.org/TR/css-color-4/ references https://www.w3.org/TR/compositing-1/#simplealphacompositing which seems to presume sRGB. https://docs.microsoft.com/en-us/typography/opentype/spec/cbdt limits itself to sRGB ("Uncompressed Color Bitmaps ... are encoded colors in the sRGB colorspace" and...

jxl is the suggested file extension and media type for jpeg xl (https://en.wikipedia.org/wiki/JPEG_XL). IMHO it would be fine for an implementation to Just Work if it saw one under graphicType...

https://lists.aau.at/mailman/private/mpeg-otspec/2023-July/002939.html references https://liebefonts.com/fonts/liebeheide as a nice example of a commercial font not readily expressed in vectors.

Reminder for self: per discussion with Raph and Chad we might want a new paint to support blending many layers with alpha. Hopefully named something nicer than PaintColorLayersWithBlendAndAlpha.

Thank you for taking the time to write this up. > two temporary image pixels to be allocated Here's the current PaintComposite and pseudocode (from https://github.com/googlefonts/colr-gradients-spec): ``` struct PaintComposite {...

Raph also noted it might make sense to explicitly model (as a Paint) a blend group w/alpha (today we do PaintComposite SRC_IN w/ a color 0,0,0,alpha [in nanoemoji](https://github.com/googlefonts/nanoemoji/blob/main/src/nanoemoji/color_glyph.py#L334))