高动态调光成像系统畸变的自校正

Self-distortion correction of high dynamic dimming imaging system

针对基于数字微镜器件(DMD)的高动态成像系统在光学设计过程中由二次倾斜造成的畸变,建立了一套基于区域的系统畸变自校正模型。首先,根据像素级区域调光高动态系统中光路设计的特点,分析了畸变产生的原因。考虑不同种类畸变模型产生的原因及特点,结合系统自身的优势,建立了一种基于区域的畸变校正函数模型。为了解决在校正过程中某一点存在多次赋值或者未赋值的情况,采用逆推校正的方法逆向求解畸变参数,进行畸变校正。最后,利用数字微镜器件(DMD)自身投影标定模板的方法,实现了系统畸变的自校正设计。实验结果表明:校正后的系统像元误差为0.87pixel。与传统的畸变校正模型相比,该模型可以有效解决系统中的倾斜畸变、径向畸变以及偏心畸变,且畸变校正过程不依赖外部环境,校正过程快、可靠性高,满足了DMD高动态系统像素级调光的要求。

For the distortion caused by a secondary incline in optical design for a high dynamic dimming imaging system based on Digital Micromirror Device（DMD）,this paper establishes a self-distortion correction model based on regioning.According to the optical path design characteristics of the high dynamic dimming imaging system,the reasons of distortion were analyzed.By taking the causes and features of different types of distortion models into account,a model was established based on distortion correction function region by combination with the characteristics of the system itself.To solve the problems of over-assignment or un-assignment in correction processing,a reverse correction method was used to solve the distortion parameters and to complement the distortion correction.Finally,the self-projection by DMD was used to calibrate the displaying template and to realize the design of self-distortion correction system.The experimental results show that the pixel error of system aftercorrection is 0.87 pixel.As compared with the traditional correction model,the model overcomes the slope distortion,radial distortion and the eccentric distortion and the distortion correction process does not depend on external environment,so it has fast and reliable correction procedure and meets the requirements of high dynamic dimming imaging systems.