Description

I'd like a way to programmatically generate PNGs inside typst from raw pixel values.

While this would technically already be possible using https://typst.app/docs/reference/visualize/image/#definitions-decode it would either 1) involve a plugin or 2) generating a PNG string in pure typst

Use Case

One good example of a place where this would be useful is for the heatmap feature in cetz

cetz-package/cetz#295

This has very poor performance, since it's literally drawing rectangles for each "pixel".