Real-time edge adaptive color interpolation for an ultra small HD-grade video sensor in mobile devices

To render a full-color image using a single image sensor, a color interpolation process is required to estimate the two missing color values at each pixel. In this paper, we present a real-time edge adaptive color interpolation method and hardware implementation for camera in mobile devices. The proposed method first calculates the edge indicators which consider horizontal, vertical and diagonal directions. At the same time, it modifies the inputted threshold values compares them with the edge indicators. Then, the proposed method decides the edge region and selects filter coefficients. Finally, the missing two color values are interpolated by using filter processing. The proposed system was implemented experimentally by using Xilinx Virtex4 FPGA and was successfully demonstrated with a CMOS sensor capturing a 720P (1280pixelstimes720lines pixels, 30fps) HD-grade video movie and a still image simultaneously.