【作者】 赵世亮；

【导师】 桂志国；

【作者基本信息】 中北大学 ， 信号与信息处理， 2010， 硕士

【摘要】 当今社会中,X射线检测在安检、医学、工业探伤等方面发挥着不可或缺的作用,已成为推动国民经济发展的一支重要力量。然而,由于X射线检测系统固有的缺陷,输出后的图像往往要经过处理才能达到要求。本文结合项目组的新型X射线成像系统,对工业成像的增强算法做了一些研究,提出了一些改进的图像增强算法,主要工作如下:1.比较详细地介绍了常规的图像增强算法,一般可分为两大类,即空域和频域增强,针对射线图像的特点,有选择地采用了不同增强算法,进行了实验验证,结果表明,常规增强算法对射线图像是有一定增强效果的;2.系统地介绍了模糊增强算法,它已成为近年来研究的热点,在传统模糊增强的基础上,本文给出了五种改进的单层次模糊增强算法,然后介绍了多层次模糊增强算法,而且每种算法都和原算法进行了定量比较,实验结果表明,改进后的算法对图像的增强效果要优于原算法;3.设计了基于小波域的模糊增强算法,它是本文的重点,本文使用了两种不同的算法来实现小波域上的模糊增强,第一种是直接对小波分解后的低频图像采用模糊增强算法,第二种是对小波增强后的图像使用模糊增强算法,详细给出了每种算法的实现步骤,而且定量比较了两种算法的优劣,增强后的图像表明,使用此类算法要优于单纯使用模糊增强和小波增强算法;4.把反锐化掩模和形态学边缘检测结合起来,构建了一个新的算法,它弥补了各自算法的不足,而且在原算法的基础上,本文都做了进一步改进和提高,采用此算法和传统的边缘检测算法增强图像作了一个比较,实验表明,此算法可以显示更多细节,边缘检测效果更明显,达到了预期目的。更多还原

【Abstract】 Nowadays,X-ray image plays an important role in the field of secure detection,mediation and industry detection etc.It becomes an important impluse for the development of country.Because of the X-ray system inherent defect, the X-ray image must be handled in the computer.Based on the new X-ray image system,we mainly study X-ray image enhancement algorithms and gives some improved algorithms.The paper mainly include :1. It introduces the usual image enhancement theory.This kind of algorithm can be divided into two categories:airspace and frequency enhancement .Based on the X-ray image,we selectively does some experiments. These algorithms have some effects the on X-ray image enhancement.2. It systemly introduces the traditonal fuzzy enhancement and gives four improved algorithms.Else,it gives improved generalized fuzzy enhancement algorithm and multi-level fuzzy enhancement algorithm.For each algorithm,it gives quantitative comparation between the former algorithm and the improved algorithm.The experiment shows the improved algorithm better than the former algorithm.3. It creates a kind of algorithm that is how to use fuzzy sets to realize image enhancement based on wavelet transform.The first algorithm uses fuzzy enhancement for low frequency of wavelet transform imageThe second algorithm uses fuzzy enhancement for image of wavelet transform enhancment.It gives a detailed description for each algorithm.What’s more,it gives quantitative comparation between two algorithms. The experiment shows that it can produce a best result of all.4. It uses unsharpening mask and mathematical morphology edge detection to design a new algorithm to realize image enhancement.It compensates defects of each algorithm.Moreover,it improves each former algorithm .Compared with the traditional edge enhancement , this algorithm makes the X-ray image more clear. The result shows that this method is feasible and useful for X-ray image enhancement.更多还原