Spatial Colour Gamut Mapping by Means of Anisotropic Diffusion

We present a computationally efficient, artifact-free, spatial colour gamut mapping algorithm. The proposed algorithm offers a compromise between the colorimetrically optimal gamut clipping and an ideal spatial gamut mapping. It exploits anisotropic diffusion to reduce the introduction of halos often appearing in spatially gamut mapped images. It is implemented as an iterative method. At iteration level zero, the result is identical to gamut clipping. The more we iterate the more we approach an optimal, spatial gamut mapping result. Our results show that a low number of iterations, 10-20, is sufficient to produce an output that is as good or better than that achieved in previous, computationally more expensive, methods. The computational complexity for one iteration is O(N), N being the number of pixels. Results based on a challenging small destination gamut supports our claims that it is indeed efficient.