Random CFAs are better than regular ones

International audienceMost of digital cameras today use a color filter array and a single sensor to acquire color information of the scene. In this paper, we ask which arrangement of colors in the mosaic of the color filter array provides the best encoding of the scene. As a solution of the inverse problem of demosaicing, we consider a linear minimum mean squared error model. We used redundancy given by the neighborhood on the sampled image to ensure the stability of the solution. For some CFAs, LMMSE with neighborhood provides equivalent reconstruction results and less variability among the image content compared to edge directed demosaicing on the Bayer. LMMSE allows comparing CFAs of regular pattern with random ones. We show that mosaics with random arrangement of colors and quasi equal proportion of RGB provide best reconstruction performance