基于互信息的高动态范围成像系统成像质量分析

为了优化高动态范围成像系统的设计,完善地评价系统性能,将信息论应用于高动态范围成像系统中,把高动态范围成像系统看作通信系统,采用端到端的互信息量来评价高动态范围成像系统的成像质量.在COMS采样成像模型的基础上引入空间光调制器反射式硅基液晶的影响,建立了基于互信息的高动态范围成像系统数学模型.利用该模型分析了反射式硅基液晶与CMOS阵列像素数比、像素开口率、相对平移、相对旋转对系统互信息量的影响及造成系统成像质量下降的原因.通过仿真计算,分别得到了像素数比例、像素开口率大小、相对平移量、相对旋转角度与互信息量的相互关系曲线,并定量分析了这些因素变化对系统互信息量的影响程度.仿真结果表明反射式硅基液晶和COMS阵列的最佳匹配条件是：反射式硅基液晶和CMOS像素的占空比尽可能大,CMOS像素尺寸尽可能小,避免相对平移和相对旋转,反射式硅基液晶像素数和CMOS像素数之比为1:1.

Image Quality Analysis of High Dynamic Range Imaging System Based on Mutual Information

 For optimizing design of the High Dynamic Range Imaging system and evaluating its performance perfectly,the information theory is applied to the High Dynamic Range Imaging system,the High Dynamic Range Imaging system is considered as a communication system,and the image quality of High Dynamic Range Imaging system is evaluated according to the end-to-end mutual information.Introducing the influence of LCoS as a spatial light modulator to CMOS sampling imaging model,mathematical model of the High Dynamic Range Imaging system based on mutual information is established.According to the model,the factors,such as the ratio of LCoS pixel number to CMOS pixel number,aperture ratio of LCoS and CMOS pixel,relative displacement and relative rotation angle,which affect the mutual information,and the reasons why the system image quality decline are analyzed.According to computer simulation,the relationships between the ratio of LCoS pixel number to CMOS pixel number and the mutual information,aperture ratio of LCoS and CMOS pixel and the mutual information,relative displacement and the mutual information,relative rotation angle and the mutual information are demonstrated,and the influence of these factors on the mutual information is analyzed.The simulation results show that the best matching condition between LCoS array and CMOS array is that one LCoS pixel corresponds to one CMOS pixel with smaller CMOS pixel,higher aperture of LCoS and CMOS pixel,no relative displacement and no relative rotation.