Synthesis of high dynamic range motion blur free image from multiple captures

Advances in CMOS image sensors enable high-speed image readout, which makes it possible to capture multiple images within a normal exposure time. Earlier work has demonstrated the use of this capability to enhance sensor dynamic range. This paper presents an algorithm for synthesizing a high dynamic range, motion blur free, still image from multiple captures. The algorithm consists of two main procedures, photocurrent estimation and saturation and motion detection. Estimation is used to reduce read noise, and, thus, to enhance dynamic range at the low illumination end. Saturation detection is used to enhance dynamic range at the high illumination end as previously proposed, while motion blur detection ensures that the estimation is not corrupted by motion. Motion blur detection also makes it possible to extend exposure time and to capture more images, which can be used to further enhance dynamic range at the low illumination end. Our algorithm operates completely locally; each pixel's final value is computed using only its captured values, and recursively, requiring the storage of only a constant number of values per pixel independent of the number of images captured. Simulation and experimental results demonstrate the enhanced signal-to-noise ratio (SNR), dynamic range, and the motion blur prevention achieved using the algorithm.