Using this small Win64 tool, an artist can pass in a color photo they would want to create a greyscale Roughness map for. For more info on Roughness maps please look up PBR rendering.
The maps are created from either a single channel of the image (R,G,B), or averaging the pixels together. The result will be a greyscale image.
GenerateRoughnessMap.exe input.png output.png (R,G,B,Average)
GenerateRoughnessMap.exe input.png output.png R