Random Noise Filtering And Motion Blur Image Restoration Technology Research

Image restoration is an important branch in the digital image processing. It also is a difficulty. Its major purpose is improving the image quality, using certain prior knowledge of image degeneration to rebuild or restore the original image. The image that may be interfered by imaging system will be of poor quality. Many valued algorithms have been proposed for various degraded images. The de-noising algorithms and a restoring technique for motion-blurred image have been presented and discussed in this thesis.Different from the linear filter, the non-linear filter can not only remove noise effectively but also keep the details of the digital images, so images can be clearer and more vivid. As an effective processing technology, the non-linear filter is widely used in the digital image processing. Median filters are representative. The typical median filter can remove the impulse noise, but it also corrupts some very important details of the images. There are some improved median filters suggested to overcome the problems. One is an image de-noising algorithm based on detection of impulse noise, It first detects impulse noise in an image by multiplex scale window, and the threshold can be modified adaptively according to the brightness value of different regions. Modified median filtering on the basis of the noise detection results is adopted to remove the impulse noise. The other is an algorithm based on threshold. A threshold is set to compare with the mean value of the pixel. If the difference between the two values is bigger than the threshold, the pixel gets value of the mean value, otherwise its value keeps invariable. The tests on many kinds of images of different noise ratios show that two methods can effectively remove the impulse noise and successfully preserve the image edge details. The first method is very worthy in bad noise. The other is very worthy of those images which have much detail, and its speed is much faster.Restoration of photographs blurred by image motion is introduced by photographic apparatus relative motion with object in exposal moment. Having universalism, the blurring image had brought trouble for people. Therefore, many persons research it, blurring by image motion become a research focus in the world now. A blur model due to uniform velocity motion is established in this thesis. Basedon result of blurring imaging pixel motion, I introduce a restoring model of blurring imaging from reverse process of degrading-process and conclude a restoring technique of motion blurring imaging from it. Then I models a blurring process for uniform velocity motion and restores it again. The example conforms the technique is available.