Minimized-Laplacian residual interpolation for color image demosaicking

A color difference interpolation technique is widely used for color image demosaicking. In this paper, we propose a minimized-laplacian residual interpolation (MLRI) as an alternative to the color difference interpolation, where the residuals are the differences between observed and tentatively estimated pixel values. In the MLRI, we estimate the tentative pixel values by minimizing the Laplacian energies of the residuals. This residual image transformation makes the interpolation process more precise than the standard color difference transformation. We incorporate the proposed MLRI into the gradient based threshold free (GBTF) algorithm, which is one of current state-of-the-art Bayer demosaicking algorithms. Experimental results demonstrate that our proposed demosaicking algorithm can outperform the state-of-the-art algorithms for the 30 images of the IMAX and the Kodak datasets.