Multi-frame demosaicing for the Quad Bayer CFA in the color difference domain

Abstract

Recently, imaging systems with submicron image sensors have been increasingly adopting the Quad Bayer color filter array (CFA) owing to its high sensitivity under low illumination conditions when pixel binning techniques are employed. Conversely, under sufficient illumination conditions, direct demosaicing methods are required for the Quad Bayer color filter array to obtain a full-resolution color image. However, the Quad Bayer color filter array is more susceptible to aliasing artifacts because of its structural disadvantages compared to the Bayer color filter array. In this paper, we propose the multi-frame demosaicing method to address this problem. The proposed method assesses local spatial contributions within local windows at each pixel to reconstruct the lost spatial resolution caused by aliasing. Additionally, we utilize the color difference domain to exploit inter-channel correlations, aiming to alleviate color artifacts and enhance spatial resolution. The experimental results demonstrate that our proposed method outperforms other methods, both quantitatively and qualitatively, including single-frame-based demosaicing methods and another multi-frame demosaicing method with pixel binning techniques.