Old Film Image Vertical Scratch Restoration Algorithm Based On Anisotropic Diffusion

Old film restoration is one of key technology and has drawn tremendous attention in research of computer vision, digital image processing, digital video processing and digital program non-linear editing technology. Because of the shortcoming of the old file production equipment and some injury caused in the process of copying, playing and storage repeatedly for film prints, the preserved films exist a lot of problem, such as flashing, spots, scratch, shaking, fade, frame lost and so on, and their visual effect is very poor. The vertical scratc is a kind of more common injury, and this paper describes the common vertical scratch of film prints detection and restoration program, which has a high application value, and the research of this field is booming in abroad and it is still in its infancy in domestic.There are two major typical algorithms about the old film vertical scratch detecting and restoration which are vertical scratch detection and restoration based on spatial characteristics and vertical scratch detection and restoration based on the Hough transform. But in recent years, with the application in image processing of partial differential equations, which become a new type of image processing tools, it attracted people’s attention gradually. Its development experiences from linear to nonlinear, and spreads from isotropic diffusion to anisotropic diffusion process. Perona and Maiik proposed P-M model based on anisotropic diffusion, mainly using a directional anisotropic diffusion, which has the effect of maintaining border, to replace Gaussian smoothing filter. This paper is mainly researches P-M nonlinear diffusion and its development model, and proposed old film vertical scratch detection and restoration algorithm based on two new anisotropic diffusion, and these two diffusion equations are introduced in detail. Anisotropic diffusion in old films vertical scratch detection acts on smoothing. Firstly, processing the image with vertical scratch through anisotropic diffusion, and get a new image, namely smoothed image. Secondly, original image and smoothed image process difference operator, and obtain difference image. Thirdly, use the single mean filtering to extract the module information of difference image, and abtain the vertical scratches module information image. Finally, according to the vertical scratches module information image, utilize the original image to subtract scratches module information image, and get the difference image which is the restored image.This paper make a lot of experiment in Matlab simulation condition, and make a lot of analyze. The results are satisfactory, and old film vertical scratch restoration algorithm based on anisotropic diffusion has some advantages of simple calculation method, spending less time and effective restoration.