CCD geometric superresolution method based on subpixel
Geng Wen-bao · Optics and Precision Engineering · 2008
In order to enhance the resolution of CCD pixel while keeping pixel dimension,the problem of CCD geometric superresolution is researched.Beginning with the actuality of superresolution,the existing methods and their shortcomings are presented,and a mathematical model of the subpixel superresolution is established.A method to improve the geometric resolution of CCD based on subpixel is presented,in which two linear CCDs staggered by half dimension of the pixel in the line direction are integrated in one component.When operated,the reading out time is reduced to half;At last,the image data is interweaved to synthesize a high resolution image.Two methods,bilinear interpolation and sub-pixel imaging,are simulated with the software MATLAB7.0.1.The qualitative and quantitative analysis are given.The simulation results show that with sub pixel imaging method,the resolution of synthesized image is twice as large as that of low resolution image,and the PSNRs in the two groups of simulating images are enhanced by 1.486 4 dB and 2.207 0 dB compared with that in bilinear interpolated image.Sub-pixel imaging method could mitigate greatly the image blur induced by under sampling,and the elapsed time is less than the bilinear interpolation method.