Similarity-based demosaicing algorithm using unified high-frequency map

This paper introduces an innovative demosaicing algorithm for color filter array (CFA). Conventional demosaicing algorithms usually detect edges in horizontal-, vertical- or omni-direction, and apply a directional filtering along the edge direction. It is found that these algorithms do not properly work for diagonal edges. We, then, invent a similarity based filtering using unified high-frequency (UHF) map. This new technique enables flexible filtering masks so as to be able to deal with edges of any direction. It is confirmed through experiments that the proposed algorithm outperforms state-of-the-art algorithms in terms of PSNR and subjective quality. In addition, the proposed algorithm requires fewer resources than the state-of-the-art algorithms.