Frequency selection and merging with universal matrices for color filter array demosaicking

In most digital cameras, color filter array (CFA) is used for sampling only one color value for each pixel on CCD. So the other two color values need to be interpolated. The interpolation process is commonly known as demosaicking. In this paper, we discuss the relationship among the down sampled CFA images in frequency domain. According to the correlation, we propose an interpolation method that select specified parts from every down sampled frequency CFA image and merge them together. For more accurate selection, we calculate the minimum error of points in frequency images, and produce some universal matrices to record the source of every point in merging. And then, interpolation is based on the universal matrices. This algorithm is a non-adaptive method and regular in hardware implementation.