Image Buffer Arrays with transparencies become black when format is JPEG

[stuible]

Really useful package, thank you for all the work you have put in. Is there any way to make the transparencies white ⚪️ instead of black ⚫️ when outputting a JPEG image?

[dy]

Thanks! Interesting question. Now it is handled by jpeg-js package, but technically it is possible to handle transparency as a separate step beforehead.