Independence between uniques and chromatic circularity

Abstract: The colour space one uses has a bearing on the type of colour image processing tasks one does. As we approach the stage of colour processing in image processing, new colour spaces may be needed. In particular, colour spaces that model properties of our perception of colour may be useful. We propose two nonlinear, tridimensional transformations of the variables of the RGB (or LMS) colour space. In the resulting spaces pure S, or pure M input, does not imply the presence of yellow. Since there is evidence of S input to the parvocelular system, we use a dimension called violet minus green; in the resulting space, as the wavelength variable sweeps the visible spectrum, a circle is obtained, making explicit a circularity of chromaticity for spectral colours.