基于像素编码的大F数高分辨成像技术研究

High-Resolution Imaging Technology for Large F-Numbers Based on Pixel Coding

为了使小口径相机具有与大口径相机同等的分辨能力,提出一种基于像素编码的高分辨成像技术。为了降低图像高、低频信息的混叠,提出基于以系统点扩展函数为运算核的像素编码算法。首先在空间域中直接构建系统的编码矩阵;然后采用求逆的方法实现对输出图像的解码,以达到提高图像质量的目的;最后利用焦距为100 mm和像元尺寸为9μm的成像系统在F数分别为11(F11)和25(F25)下进行室内实验验证,采用像素编码算法对F25系统所成的鉴别率板像进行校正,校正后的调制传递函数值(0.18)与F11系统(0.24)相当,图像对比度得到提高,验证像素编码算法的合理性和可行性,使得小口径相机具备高分辨率的成像能力成为可能。

To realize small-aperture cameras with the same resolving power as large-aperture cameras,a high-resolution imaging technology based on pixel coding is proposed.To reduce image aliasing at high and low frequencies,a pixel coding algorithm based on the system point spread function as the computing core is proposed.First,the encoding matrix of the system is directly constructed in the spatial domain.Then,the inversion method is used to decode the output image for enhanced image quality.Finally,the imaging system with a focal length of 100 mm and a pixel size of 9μm is developed.The F-numbers of 11(F11)and 25(F25)are used for indoor experimental verification.The pixel coding algorithm is used to correct the image of distinguish plate obtained using the F25 system.The value of the corrected modulation transfer function(0.18)is equivalent to that obtained using the F11 system(0.24),and high image contrast is obtained.The experimental results verify the feasibility and effectiveness of the pixel coding algorithm,thereby allowing small-aperture cameras to achieve high-resolution imaging.