Subsampled device-independent interchange color spaces

This paper extends the authors' work on device-independent interchange color spaces. The authors add the additional requirement that a desirable interchange space exhibit good performance when two of its dimensions are encoded at lower spatial resolution than the other constituent, either by subsampling or other methods. Many important bandwidth compression algorithms use such encodings. The authors define luminance contamination, a new measure for interchange space performance under subsampling, supply a test for this property, and report results for a set of proposed device-independent color spaces. The occurrence of large, infrequently occurring errors in RGB color spaces with low luminance contamination is also reported. The authors discuss the conversion of a device-independent representation to popular device spaces by means of trilinear interpolation and find, for a given accuracy, some spaces require substantially fewer lookup table entries than do others.