In order to enhance the resolution of CCD pixel while keeping the pixel dimension

the problem of CCD geometric superresolution is researched. Beginning with the actuality of superresolution

the existing methods and correlative shortcomings are given

and the mathematic model of the subpixel superresolution is constituted. The method for improving the geometric resolution of CCD based on subpixel is presented. Two linear CCDs

which are shifted by half dimension of the pixel in the line direction

are integrated in one component. In operation

the reading_out time is reduced by half. At last

the image data is interweaved to synthesize the high resolution image. Two methods

bilinear interpolation and sub_pixel imaging

are simulated with the software MATLAB7.0.1. The qualitative and quantitative analysis is given. The simulation show that in sub_pixel imaging method

the resolution of synthesized image

compared with low resolution image

is enhanced by about one times

and the PSNR

compared with bilinear interpolated image

is enhanced by 0.2 dB. Sub_pixel imaging method could synthesize high resolution image in real time

and the image blur

which is induced by under sampling

is mitigated greatly in this method.