Theory and experiment study on low-light-level (LLL) image by topology mode filters

摘要

Abstract: Real-time low light level (LLL) image processing technology is the important developmental subject in the area of LLL night vision. But there is an essential distinction between the LLL TV image and the ordinary TV image, so the conventional digital image processing techniques are not suitable for LLL image. In this paper, on the basis of the analysis on the main noise sources of the LLL CCD TV System that our research laboratory developed, new types of theory and technique, topology mode filters, are put forward and taken to process LLL image. Topology mode filters include linear combination of mode filters, weighted-mode filter, iterated-mode filter and adaptive-mode filter. The LLL Image Processing System and the LLL TV Signal and Noise Test and Analysis System are set up specially. By using topology mode filters, the LLL image quality is improved greatly and the processing results are given out. Theory and experiment results show that topology mode filter is better than simple mode filter.!4