Encoding/Escape in spawn (Node.js, Child-Process)

Question

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=85%', '-remap', tempFilePath_Map, '-type', 'Palette', 'BMP3:' + tempFilePathBitmap]);

The following option is not executed in the firebase backend. Everything else works fine.

dither:diffusion-amount=85%

I assume, i need to escape some characters in this string. How can i do that?

Thanks.

Answer 1

It seems, that Google is running on an older version (V.6) of Imagemagick which is not supporting dither:diffusion-amount.