Color Remap / dithering composer node

I've used ImageMagick recently to do some 256 colors graphics, particularly this command:

magick.exe .\test0.png -dither FloydSteinberg -define dither:diffusion-amount=30% -remap .\WTRCYAN.bmp .\test1.png

It would be nice to have a node that takes those parameters:

Inputs:

• Image to remap the colors/apply dithering
• Image that contains the color map

Outputs:

• Image remapped

Parameters:

• Dithering method (Floyd-Steinberg, Positioned, No dithering)
• Dithering diffusion amount in %

I've tried to do it in C++ as I have some experience in development, but I failed to read the image colors and somehow pass it to the operator that does the color conversion.