Evaluation of Spatial Gamut Mapping Algorithms

We propose an independent evaluation of Spatial Gamut Mapping Algorithms (SGMAs) by a psychophysical experiment comparing five gamut mapping algorithms, two point-wise and three spatially adaptive applied to fifteen images. Results show that reproduction from SGMAs were rated best, and indicate that among SGMAs, observers attached more importance to the preservation of saturation and of global contrast than to the rendering of details. The results of these psychophysical experiments are then compared to selected Image Quality Metrics (IQMs) to investigate their possible utilization in the implementation and evaluation of new GMAs. The comparison demonstrates that while IQMs do not present a conclusive correlation, they are still able to extract useful information about the local distortion caused by the gamut mapping algorithms.