PNG transparent color becoming black in JPG format

[ralphilius]

Here is my code:

image.format = targetFormat as MagickFormat;
image.backgroundColor = new MagickColor(255,255,255);
const blob = await image.write(async (data) => {
  return new Blob([data], { type: `image/${targetFormat}` });
});

How do I get the transparent part of PNG images to white?

[dlemstra]

You can use image.colorAlpha(MagickColors.White) to do that.

[ralphilius]

Thanks. It's working.