【作者】 高彦平；

【导师】 郑永果；

【作者基本信息】 山东科技大学 ， 计算机软件与理论， 2005， 硕士

【摘要】 在图像处理中,图像增强技术对于提高图像的质量起着重要的作用。它通过有选择地强调图像中某些信息而抑制掉另一些信息,以改善图像的视觉效果,将原图像转换成一种更适合于人眼观察和计算机进行分析处理的形式。 本文着重对图像增强方法中的灰度变换、直方图均衡化、模糊增强进行了深入的研究,针对增强过程中遇到的一些问题,提出了相应的解决方法。 对于分段线性变换方法中如何划分灰度区间进行变换这一关键问题,给出了基于区域分割的分段线性变换方法,加快了调整灰度区间的过程,提高了算法的执行效率。 为了适应图像的局部亮度特性,给出了基于抛物线调整的直方图均衡化方法,可以调节图像的明暗程度,增强区域的对比度,同时给出了一种选择最优参数的方法。 通过调整直方图均衡化后像素的灰度值,给出了保留灰度级的直方图均衡化方法,丰富了图像的灰度层次,一定程度上消除了灰阶合并现象对图像带来的影响。 对传统的模糊增强方法加以改进,利用正弦隶属度函数进行模糊增强,从而避免增强后大量灰阶信息的丢失,同时加快了最优参数的选择。在模糊增强的基础上进行灰度线性变换,进一步改善图像的增强效果。 实验表明,本文给出的图像增强方法对于一些图像取得了比现有的一些增强方法更好的增强效果。更多还原

【Abstract】 Image enhancement technology plays a very important role to improve image quality in image processing. By enhancing some information and restraining other information selectively it can improve image visual effect and transform an image to another form which adapts to human observation or computer analysis and processing better.This paper makes an exhaustive study of some enhancement methods such as gray scale transformation, histogram equalization and fuzzy enhancement. It puts forwards correspondence methods to solve some defects during the course of image enhancement.Aiming to the key problem of how to divide gray scale intervals, this paper puts forward a method called segmental linear transformation based on region segmentation. It accelerates the process of adjusting gray intervals and is an efficient method.In order to adapt to image local regional brightness characteristic, this paper puts forward a method called histogram equalization based on parabola modification. It can adjust the brightness and enhance the contrast of local region. At the same time it puts forward a method of how to select optimum parameters.By adjusting gray level values of pixels after equalization this paper puts forward a method called histogram equalization of preserving gray levels. It can make gray level layers more abundant and dispel the amalgamation of gray levels to some extent.This paper improves traditional fuzzy enhancement method. It uses sine membership function for fuzzy enhancement. So it avoids a large amount of the missing of gray scale information. At the same time it accelerates the selection of the optimum parameters. On the basis of fuzzy enhancement gray scale linear transformation is used to improve image enhancement result further.Experiences show that the methods of this paper obtain better enhancement更多还原