Space-time-domain median filtering in low-light-level noise processing

The random flicker noise is the main character of low-light- level (LLL) image, so the noise suppressing is a key technique for LLL image processing. In this paper, the noise sources and its characteristics of LLL image are studied, and varied existing noise processing techniques are analyzed. On the basis of these, a novel filtering approach, space-time domain median filter, is presented. In this approach, the time correlation of LLL TV image is utilized and the time domain median filter is combined with the space domain median filter. Therefore the LLL image noise is reduced significantly, and the quality of LLL image is improved greatly.