The Research On Restoration Of Defocus Blurred Image Based On Circular Symmetry

Big data era has arrived,image streaming media play an increasingly importantrole in the data age.CMOS(Complementary Metal Oxide Semiconductor) andCCD(Charge Coupled Devices) as the representative of the new sensors have a morebroad application space. Universal application for CMOS and CCD provides thefoundation digital image processing technology. Including image enhancement,image restoration, image coding and image segmentation.Restoring defocus blurred images have many application needs in real life, theimage reduction technology has been one of the hot issues of image processingresearch. Restoring defocus blurred image is a diiffcult problem of imageapplications, defocus blurred image appeared degradation, so that the imageinformation is not complete. In order to obtain high-quality images. We have storedthe image, the restored image of high quality is the subject of our study.The basic theory of Restoration of Defocus Blurred Image and made the introdution, speciifcally on the traditional methods of d Restoration of Defocus Blurred Image. What is the point spread function, line spread function，a function of the blade edge, but also introduces some of the more common reduction method, Wiener filtering,blind algorithms and so on.In the final chapter, speciifcally describes two models of Restoration of Defocus Blurred Image, one is defocus blurred disc model, one is defocus blurred Gaussianmodel.Describes the traditional methods of the sharpness evaluation function, thereare gray scale function, gradient function, gray entropy function, frequency domain class functions, Then describes sharpness evaluation function based on sobel operator,On the basis of the sharpness evaluation function the based on the central weighted block ofDCT,This paper proposes improved the sharpness evaluation function based on the center block ofDCT coefifcients weighted.Finally, we made experiments with Restoration of Defocus Blurred Image Based on Circular Symmetry, Compared with traditional methods and models used previously. Restoration of Defocus Blurred Image Base d on Circular Symmetry improve the sharpness of image, Signiifcantly improved quality of an image.