【作者】 张瑾；

【导师】 陈向东；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2006， 硕士

【摘要】 近年来,红外图像被广泛应用于许多领域。然而,由于红外探测器的固有特性所产生的噪声污染、边缘模糊等现象对红外图像造成了严重的影响。为了降低这类现象对红外图像的影响、改善图像质量,本论文引入了小波分析技术。小波变换将图像分解到不同分辨率尺度,这一特性非常适合于图像分析,并且通过小波变换重建后,被处理的图像质量能有效地改进。 本论文主要对红外图像的去噪技术和边缘检测技术进行了研究,完成了以下一些工作:介绍了小波变换的一些关键技术;提出了一种基于小波系数阈值处理的红外图像去噪方法,该方法针对红外图像的噪声分布特性,对红外图像中的乘性噪声进行对数变换,使乘性噪声变为加性噪声,并对变换后红外图像的小波变换系数进行阈值处理实现图像去噪;在分析小波多尺度边缘检测技术以及噪声和边缘小波变换的不同规律的基础上,提出了一种基于传统边缘检测算法的改进算法。 仿真结果表明,本文所提出的红外图像去噪算法比传统的小波变换方法对噪声有更好的抑制作用;基于传统边缘检测算法的改进算法能够有效的增强图像边缘的清晰度和连续性。综上,本文所提出的算法对红外图像的噪声平滑、细节保持、目视质量有相当程度的改善。更多还原

【Abstract】 In recent years, infrared images are applied widely to many domains. However,much noise and blurred edge is a serious problem to the infrared images because of the inherent character of infrared detectors. In order to reduce these phenomena and improve the image quality the technique of wavelet analysis is introduced.The wavelet transform decomposes an image into a finite number of resolution scales that is very suitable for image analysis. And after the wavelet reconstruction, the visual quality of the processed images can be improved effectively.The research is mainly focused on the Infrared image de-noising and edge detection based wavelet transform.The new results are as follows: introduced some key problems of wavelet transform, proposed a scheme of infrared image de-noising based wavelet threshold processing.Aimed at the characteristic of noise distribution, the multiplicative noise in infrared image is turned into additive noise using a logarithm. By thresholding the wavelet coefficients of noisy infrared image, the de-noised image can be reconstructed. By the analysis of wavelet multi-scale edge detection principle, and different regulation of wavelet transformation to the noise and edge, we developed traditional-based improvement edge detection algorithm.The simulation results show that the image denoising effect of our scheme has obvious superiority compared with general wavelet transform method. And our improvement edge detection algorithm can increase the edge clearness and continuity. In a word, such schemes can achieve a considerable improvement in noise smoothing, details-preserving and the visual quality of infrared images.更多还原