Suggestion: Make a factory method where you can put in a pre-existing array of pixel data previously obtained (like from a file)

[janerivi]

something like PNG.makeFromRgbaData(width,height,arrayRGBA); and it will return a PNG instance from your pre-existing data. I was about to try to implement it myself.. but I was confused about how the buffer was set up in your code.

The usecase is for the typical PNG data with 8 bits channels for r,g,b and alpha (wich is what people use 99.99 percent of the time I would assume.

[IjzerenHein]

Hi. So this library currently only supports 8-bit indexed colors. The library is a port of an an older version of pnglib, but then modernized and faster. 32 bit colors are not yet supported though. Once that is supported, creating such a factory function would be trivial. I currently don't have any time to add it though, any PRs in this space would be welcome.
Cheers Hein

[IjzerenHein]

Hi, I just stumbled upon this. This may exactly be what you need:
https://github.com/photopea/UPNG.js

cheers