Influence of automatic brightness control on the adaptation of low-light-level TV to high light

The influence of automatic brightness control on the adaptation of low-light-level TV to high light is quantitatively analyzed. First, combined with signal response characteristics, the relationship between the high light energy and the system imaging contrast is established. Then, simultaneously considering dynamic range, gain characteristic and gray level quantization, a feature quantitative model of low-light-level TV imaging after automatic brightness control operation is built. Finally, the digital simulation model of the imaging of the system which is disturbed by high light with automatic brightness control circuit, is established on the basis of the model aforementioned. Furthermore, an analysis of the effect of high light with different energy on the investigation ability of the system is deduced based on the analog output image. The theoretical analysis and experimental simulation results show that, the automatic brightness control expands the dynamic range and enhances the usability of the system, but it results in the declination of imaging quality and reconnaissance performance of the system.