The parameter calculation and frequency spectrum analysis of the defocus blurring image

It is inevitable to defocus in aerial cameras' photographing for various factors. The calculation of focus shift, i.e. the detecting of focus, is the absolutely necessary segment in order to improve the quality of imaging and to enhance the resolution of the camera in photographing. So, it can be accomplished to focus for the cameras. An effective method to evaluate the defocus parameter to the camera utilizing the way of power spectrum calculation is given by analyzing the course of imaging to the defocus blurring. It's intuitionistic and easy to carry out, which also can be expanded to other kind of calculation of motion blurring parameter.