为提高便携式多波段相机在宽照度环境下的拍摄需求,针对传统多区域均值加权曝光时间调节算法中图像灰度参考均值的取值范围对调光性能影响大的问题,提出了一种基于便携式多波段相机的多区域均值加权调光和图像信息熵调光相结合的调光方法。系统采用多区域均值加权调光方法,实现了过高或过低图像灰度情况下的快速调光;利用图像信息熵调光方法,解决了传统调光算法中超调振荡问题,提高了便携式多波段相机的照度环境适应性;进行了基于便携式多波段相机的调光实验,调光时间为31ms,消除振荡时间约为180ms。实验结果表明,利用多区域均值加权和图像信息熵相结合的调光算法可快速、稳定地选择合适的曝光时间,获得更好的多波段拍摄结果。
In order to meet the requirement that the portable multi-band camera can be used in largescale illumination environment, the exposure time adjustment algorithm of the multi-region mean weighted combined with the image entropy was proposed to resolve the problem that the impact of image reference mean to the performance of algorithm based on the multi-region mean weighted exposure time adjustment was heavy. The multi-region mean weighted exposure time adjustment algorithm was adopted for fast adjustment when the gray value of the image is too high or too low, and the image information entropy exposure time adjustment algorithm was used to eliminate the overshoot oscillation. Based on the portable multiband camera exposure time adjustment experiment, the exposure time was 31 ms, the eliminating oscillation time is about 180 ms. The results show that the use of the exposure time adjustment algorithm of the multi-region mean weighted combined with the image entropy can rapidly and stably choose appropriate exposure time, and the camera can get good image.