Legacy ImageMagick Discussions Archive

When converting a 16 bpp grayscale image into a 8 bpp grayscale image with -remap using a palette of 256 distinct shades of gray, the resulting image is only made up of no more than 64 distinct shades of gray. The expected behavior would be the creation of an image using the full range of shades ...

I've got a program that users can upload images. The instructions say to always make the visual, background color 256 256 256; but they don't do so. The images are simple street maps. I'd like to be able to determine if the background is grey, light green, or whatever, and convert it to white ...