CMOS图像传感器自适应动态范围调整曝光控制

Exposure algorithm for CMOS image sensor with adaptive dynamic range

介绍了一种基于CMOS图像传感器的自适应动态范围调整曝光控制方法。该方法采用有源像素多斜率积分技术,通过判别亮度直方图的分布特征,确定积分时间序列的长度和比例,实现了能够适应场景照度范围变化的可调动态范围成像系统。分析了积分参数与传感器响应曲线及动态范围扩展倍数的关系,给出了相机时序控制电路设计中的关键技术,进行了FPGA仿真验证和成像实验。该方法可应用于空间目标成像等动态范围宽,光强变化大的场合。

A novel auto exposure algorithm for CMOS image sensor was developed to build an imaging system with adaptive dynamic range extension for fluctuant scenes. Using the multiple - slope feature of photodiode pixel, the proposed method derived optimum integration time series from the luminance histogram of previous frame. The mechanism of modifying response curve and dynamic range was analyzed. The system design of control circuit was presented along with timing simulation and FPGA verification. The experiment shows that better image quality can be obtained under wide lightening conditions, and this algorithm was suitable for space applications.