Color demosaicking via fully directional estimation.

Given a natural image from the single sensor, the key task is to properly reconstruct the full color image. This paper presents an effectively demosaicking algorithm based on fully directional estimation using Bayer color filter array pattern. The proposed method smoothly keeps access to current reconstruction implementations, and outperforms the horizontal and vertical estimating approaches in terms of the perceptual quality. To analyze the target of existing methods, the proposed algorithm use the multiscale gradients in single green channels as the diagonal information for the auxiliary interpolation. Furthermore, two group of weights (one is from the horizontal and vertical directions, another is from the diagonal and anti-diagonal directions) are built. Combinational weight is better suited for representing neighbor information. Another contribution is to better use the prior result. While calculating the same type of color difference, we divide all the color difference values into two interleaved parts. Estimated value in the first part will guide the subsequent color difference in the second part. It less brings the artifact of the interpolation procedure. Experimental results show that this adaptive algorithm is efficient both in the objective and subjective output measures.