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运动模糊图像恢复算法的研究与实现

Research and Implementation of Algorithm for Restoration of Motion Blurred Images

【作者】 贾宝华

【导师】 李宇成;

【作者基本信息】 北方工业大学 , 检测技术与自动化装置, 2010, 硕士

【摘要】 运动模糊图像复原是图像复原技术中十分重要的一个分支,在生产生活领域、航天领域、智能交通领域都有着广泛的应用。由于匀速直线运动模糊是具有普遍意义的一种退化方式,本文针对匀速直线运动模糊图像的复原进行了系统的研究。建立恰当的退化模型和准确的辨识模糊参数是良好复原退化图像的关键。本文首先根据匀速直线运动模糊图像的特点建立了相应的退化模型,得出其点扩散函数是由模糊长度和模糊角度确定的。对于匀速直线运动模糊图像,其频谱图像中存在平行排布的暗条纹,这些暗条纹的生成与退化图像的模糊参数存在特定的关系。本文通过对匀速运动模糊图像的频谱出现平行暗条纹的原因的分析,推导了匀速运动模糊图像点扩散函数的离散域表达式,找到了退化图像频谱暗条纹方向和间距与退化图像模糊参数之间的关系式。本文使用Radon算法对暗条纹方向进行检测,使用投影法对暗条纹间距进行检测,然后根据得出的关系式确定退化图像的模糊角度和模糊长度。对于真实退化的运动模糊图像,使用维纳滤波法对其进行复原后,复原图像会出现较强的振铃效应,本文通过分析局部退化图像形成的原理,找到了一种对局部退化图像预处理的方法,使真实局部退化图像逼近仿真退化图像,这种预处理方法可以有效地改善具有简单背景的退化图像的复原质量。

【Abstract】 Motion blurred image restoration is an important branch in the digital image processing, which has been widely used in various fields as production and living, spaceflight, and intelligent transportation. The restoration of uniform linear motion blurred image, the degradation mode of which has a universal significance, is discussed in details in this paper.The key point to restore a degraded image is to establish the degradation model appropriately and identify the blur parameters accurately. Firstly, the degradation model is established according to the features of a uniform linear motion blurred image, which reveals that the point spread function of a degradation model is determined by the motion blur direction and blur length.Parallel-arranged dark strips, the generation of which has a particular relationship with the motion blur parameters; can be found in the spectrum of a uniform linear motion blurred image. The mechanism of the generation of parallel-arranged dark strips is analyzed in details in this paper, through which the point spread function (PSF) and the 2-d discrete expression of degraded images are deduced, and through which the correct relationship between linear motion blur parameters and the orientation and space of the dark stripes are found. The Radon transform and Projection transform are used respectively to detect the orientation of strips and the space between strips, and parameters blur angle and blur length of the degraded image are determined consequently.Through the analysis of degradation principle of local degraded image, an image preprocessing method for a local degraded image is presented in this paper, through which a practical degraded motion blurred image that usually has significant ringing effect after being restored by using wiener filtering can have a similar quality with stimulated image, and the effectiveness of which has been proved in improving the restoration quality of degraded image with simple background.

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