I would like if there is a tool useful to change an image's colors (intended for bi-dimensional game sprites) with the following criteria:
- Overall purpose: I have a specific sprite set from a website. Those sprites are good but there are no enough color alternatives for such sprites, and I would like to take a sprite and map their colors to generate other sprites, with same shape, but different colors.
- The utility must be stand-alone. Actually, it can be a software piece made of interpreted code (say: python, ruby) but this criterion stands for software which is not part of a bigger software (i.e. a plug-in of a damn-heavy software).
- The tool should be able to choose or classify image pixels by having some properties (HSV-related properties are important to me), and apply a user-defined transform to those properties (either relative or absolute). E.g. say "take the pixels with a hue near to pure red (+/- 10), and add 120 to the hue" (in this sense, red-like points would turn green-like points).
- The tool should allow me to either run it by command line or support a range of transforms (this last point would mean: generate an image with green-like points by adding 120, cyan-like points by adding 180, ... and several images as I want without having to manually restart the overall process).
- The utility has to be run on Linux, or be made on an interpreter language with multi-platform support like Python or Ruby (or even Java).