An Effective Color-difference-based Demosaicking Method

This paper proposes an effective color-difference-based (ECDB) interpolation algorithm for color filter array (CFA) image demosaicking. A CFA image consists of a set of spectrally selective filters which are arranged in an interleaved pattern such that only one color component is sampled at each pixel location. To improve the quality of reconstructed fullcolor images from CFA images, the ECDB algorithm first analyzes the samples immediately around a missing green pixel to determine suitable samples for interpolating the value of this missing green pixel. After finishing the interpolation operations of all the missing green pixels, a complete green plane (i.e G plane) is obtained. The ECDB algorithm then makes use of the high correlation between the R, G, and B planes to produce the red–green and blue–green color difference planes and further reconstructs the red and blue planes in successive operations. Because the green plane provides twice the information of the red and blue planes, the algorithm uses the information of the green plane more than that of the red/blue planes so that the full color image can be reconstructed more accurately. In essence, the ECDB algorithm uses the red–green and blue–green color difference planes, and develops different conditional operations according to the horizontal, vertical, and diagonal neighboring pixel information with a suitable weighting technique. The experimental results demonstrate that the proposed algorithm performed extremely well.