为了对高动态范围场景进行实时有效的观测,设计了一种采用数字微镜器件作为空间光调制器的成像系统.通过改进数字微镜器件的驱动时序,提高数字微镜扩展成像系统动态范围能力.针对光学系统存在畸变,采用多项式拟合法获得数字微镜器件到图像传感器的精确映射关系.针对一般调光算法导致调光后图像可视性差的问题,引入色阶映射算子生成调光模板,获得符合人眼视觉特性的调光结果.实验结果表明,在10帧/s的条件下采用数字微镜器件可提高传统成像系统动态范围66 dB,成像系统总的动态范围达到126 dB,图像传感器控制准确度达到0.69个像素级别,调光后场景高亮目标与暗背景可同时观测到,调光后采集图像的信息熵得到提高,系统满足对高动态范围场景实时成像观测的需求.

In order to observe high dynamic scene effectively and in real time,an imaging system based on digital micromirror device as a spatial light modulator was designed.The capability of digital micromirror device was improved in increasing the dynamic range of imaging system by improving the driving timing of digital micromirror device.To tackle the distortion error of the optical system,polynomial fitting was employed to acquire the mapping relationship between digital micromirror device and imaging sensor.Finally,in order to resolve the problem of poor visuality when using ordinary light adjusting algorithm,tone mapping operator was introduced to generate a light adjusting template and image with better visuality was acquired.The results indicate that the dynamic range of traditional imaging system can be increased by 66 dB under the condition of 10 frames per second and the total dynamic range of the imaging system reachs 126 dB.Morever,the precision of using digital micromirror device to control imaging sensor is up to 0.69 pixel,bright part and dark part in a high dynamic range scene can be displayed simultaneously in one image after light adjusting and the entropy of image collected after light adjusting inreased.The imaging system meet the requirement of real time observation in high dynamic range scene.