Sequential RGB color imaging with a millimeter-scale monochrome camera with a rolling shutter

Abstract

Applications are growing for ultracompact millimeter-scale cameras. For color images, these sensors commonly utilize a Bayer mask, which can negatively and perceptibly have an impact on image resolution and quality, especially for low pixel-count submillimeter sensors. To alleviate this, we built a time-multiplexed RGB LED illumination system synchronized to the rolling shutter of a monochrome camera. The sequential images are processed and displayed as near real-time color video. Experimental comparison with an identical sensor with a Bayer color mask showed significant improvement in the MTF curves and to perceived image clarity. Trade-offs with respect to system complexity and color motion artifacts are discussed.