关键字：图像复原 图像去模糊 运动模糊 பைடு நூலகம்纳滤波
With the development of science and technology, the requirement for image quality is higher than before. In particular condition, we cann’t get very clear image from the image acquisition device. There are many factors influencing the image quality, such as the low quality of image acquisition device. They result in the missing of image detail. Besides, the light intensity may lead to the reduction of image contrast. Our purpose is to get high quality image that contains large number of detais from the degraded image. In practical application, it’s more important to extra detail and edge information. We want to get the license information that offends vehicle, or the disease information. Thus, it’s necessary to improve image quality by restoration of the degraded image.
论文分析了运动模糊产生的原因，建立其退化模型，对该模型中的点扩散函数进行估计，具体表现为模糊角度和模糊尺度估计，最后采用维纳滤波复原，完成整个图像去模糊过程。针对图像复原中产生的振铃效应，分析其产生的原因，在获取、传输、存储图像过程中，不可避免地引入噪声，因此，在图像预处理阶段通过haar小波去噪，以抑制振铃效应的产生。
武汉理工大学
现代数字信号处理（论文）
随着科技的发展，人们对图像质量的要求也越来越高。在特定的应用场合，图像采集设备得到的图像质量比较低，造成细节信息丢失，加上光照的干扰，使得图像对比度降低。我们需要从退化图像中，得到细节信息丰富的图像。交通、医学图像领域，更关注边缘和细节信息的提取，期望获得违规车辆的车牌号，或人体病变位置的信息，因此对降质图像进行复原，就十分必要了。图像复原旨在由降质图像重建清晰图像，当被拍摄物体与相机之间存在相对运动时，就会产生运动模糊，导致图像质量下降，由于运动模糊的普遍存在性，通过算法对图像进行去模糊，以期得到清晰的图像。
Key words: digital image restoration; image deblurred; motion blur; Wiener filter
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1.1 研究背景及意义
视觉器官是人类的高级感知器官，人类通过视觉系统获取对机体生存有意义的信息，将信息直观的显示出来即图像，所以图像在人类感知中扮演着重要的角色。图像信息以其直观性、易存储、易传输等特点，成为人类分析及利用信息的重要手段。数字图像处理技术在20世纪20年代发展起来，随着CT的发明和计算机的问世，大量医学图片通过图像处理技术进行分析处理，使得该技术有了很大的发展，现在图像处理技术广泛应用于医学图像、遥感卫星、安防、交通、军事等领域。由于外界条件的影响、图像采集设备的缺陷，在图像的传输过程中会造成图像信息量的丢失，导致获取的图像呈现各种不理想的状态，图像复原技术[1]应运而生，并成为图像处理技术的重要组成部分。
Digital image restoration aims at constructing the original image from the degraded image. Motion blur is very common in various degraded pattern. When there is relative motion between the image acquisition device and the object, the motion blur occurs. It results in the degrade of image quality. We need to clear image by programming to get clear image. The thesis analyzes the causes of motion blur, and builds the degraded model. Then the estimation of motion blur parameters is introduced in the model, that contains blur angle and length estimation. At last, Wiener Filter is adopted for restoration. With the appearance of Ringing Effect, The whole image deblur process is completed. Analyze the causes of Ringing Effect in the image restoration, we conclude that noise is the main factor. In the process of obtaining、transporting and saving image, noise is inevitable. Thus, haar wavelet is used for denoising in image pre-processing stage to suppress the ringing effect.