A demosaicing algorithm based on adaptive edge sensitive and fuzzy assignment in CMOS image sensor

In order to ensure the PSNRs of the demosaiced images of CMOS image sensor and reduce the computational cost at the same time, the proposed demosaicing algorithm in this paper improves on adaptive edge sensitive algorithm and fuzzy assignment algorithm. In order to estimate the direction of edges more accurately, it adds two adjacent pixels of the current pixel as the judgment condition and classifies the edges into strong edges and weak edges. The proposed algorithm adopts fuzzy assignment algorithm to estimate the missing green value at red/blue pixels and assigns different weighting factors according to the results of edge detection. Our comparison on PSNRs and computational cost with several other typical algorithms is performed on Kodak photo CD data sets. The results show that the PSNR value of the G channel improves 1.99dB more than the adaptive fuzzy assignment algorithm and improves about 0.66dB more than the complex algorithm based on variance of color differences and weighing based algorithm. However, the addition operation of the proposed algorithm is only one-fifth of the algorithm based on variance of color differences with nearly the same multiplication and bit-shift operations. The proposed algorithm can get similar PSNRs without affecting the quality of the image and at the same time reduce the computational cost.