I'm trying to port a Photoshop Action to ImageMagick, and I'm having some trouble with the step where I need to reduce the number of colors to a specific palette.
In Photoshop, it's possible to use the Indexed Color option to define a limited palette of colors (in my case, 8 precisely chosen colors and 4 wildcard colors which Photoshop gets to choose based on the specifics of each image):
Note that the total number of colors is 12, but the Forced Colors palette only defines 8 specific colors. (As mentioned above, there are 4 "wildcard colors" that Photoshop gets to choose.)
So, my two specific questions:
1. Is it possible to replicate this forced palette + wildcard color functionality with ImageMagick?
2. What is the ImageMagick equivalent of Dither: Diffusion and Amount: 30%? I've noticed the dithering results I get from Photoshop are much better than the dithering results I get from ImageMagick. I've played around with all sorts of IM dithering options, but I can't seem to get the same high quality results.