Optimal Noise-Aware Imaging with Switchable Prefilters

Abstract

Most consumer digital cameras employ a single-chip image sensor with a color filter array (CFA), where the purpose of an in-camera imaging pipeline is to generate a noise-free and color-corrected standard RGB image from mosaic CFA RAW data. The joint design of camera spectral sensitivity (CSS) and the imaging pipeline has great potential to derive better imaging quality. However, since there is a trade-off between the robustness to noise and the accuracy of color reproduction, one fixed CSS cannot realize optimal imaging in terms of both aspects under various noise levels. Thus, in this paper, we propose noise-aware imaging using camera prefilters for each noise level, where we jointly design the spectral sensitivity of the prefilters, that of CFA, and imaging networks to realize optimal imaging in all noise levels. Experimental results under various noise levels demonstrate that our imaging method using the prefilters outperforms existing methods based on a fixed CSS.