Problem with dither:diffusion-amount=20% with Firebase

[v11]

Hello

I am building a small webapp with Firebase to provide e-paper-ready images. To convert images to bitmap i am using a cloud function (node.js).

I have the following string in a Node.js Firebase Cloud Function:
await spawn('convert', [tempFilePath, '-resize', displaySize + '^', '-gravity', 'center', '-extent', displaySize, dither, ditherValue, '-define', 'dither: diffusion-amount=20%', '-remap', tempFilePath_Map, '-type', 'Palette', 'BMP3:' + tempFilePathBitmap]);

Which should be equal to this:
convert image.pngl -resize 600x448^ -gravity center -extent 600x448 -dither FloydSteinberg -define dither:diffusion-amount=20% -remap eink-7color.png -type Palette, BMP3:images.bmp

It works very well. But: The following option has no effect:
dither:diffusion-amount=20%

I think Google is still running Imagemagik V6 (ImageMagick 6.9.7-4). I read that somewhere. If yes, is the diffusion-ammount command available at all?

Or has it something to do with the %-sign? Do i need to escape it correctly?

Any help is very welcome.

Lukas

[v11]

I just realized that Google is running on ImageMagick 7.0.10-48. I open a new discussion in the corresponding repo: ImageMagick/ImageMagick#3023

This discussion can be deleted.