【作者】 杨鸿波；

【导师】 于明；

【作者基本信息】 河北工业大学 ， 微电子学与固体电子学， 2002， 硕士

【摘要】 视觉描述中的对称性特征检测的研究涉及到图像处理、模式识别、计算机视觉、生物生理学、心理学等学科。对称性分析一直是图像理解、计算机视觉研究的重要内容。对称性可以影响人的注意机制，从而指导后期视觉的物体检测、特征提取与识别过程，而且对称性也可以作为进行物理、化学研究和医学诊断方面的重要的指导参数。随着基于内容的图像检索技术的飞速发展，对称性检测技术不断完善，于是在更多的领域内得到了广泛地应用。 本论文针对视觉描述中的对称性特征检测的重要问题：图像中的具有对称性特征的点集提取，镜像对称图像的对称轴的定位等问题进行了深入研究。首先利用图像的相位信息，模仿人类大脑中视觉特性，计算图像的相位一致函数，找到一个基于小波变换的对称性度量；并且根据这个度量，提取图像中对称的区域。其次计算图像的局部能量的梯度方向直方图，寻找图像的对称轴位置，最后利用此算法对一组具有对称目标的图像进行处理，实验表明该算法能够自动寻找对称轴的位置和数目，高效地对硅藻图像进行检索，方法快速且具有实用性。 本课题的软件在Matlab5．2环境下编写生成，在IBM PC586(主频400M)上调试通过。实验所用的图像为8位灰度值图像。本文方法对利用图像的对称性特征进行基于内容的图像检测方面有比较乐观的应用前景。更多还原

【Abstract】 The detection of symmetry feature in visual feature description is emerging as an active research area involving several subjects such as image processing, pattern recognition, computer vision, physiology, psychology, and so on. The detection of symmetry is always the important content of understanding of the image, and computer vision. Symmetry feature can influence the mechanism of human’s notice so that can instruct the detecting, selection and recognition of the object in human’s evening vision. Symmetry feature is also treated as important parameter in physical, chemical research and medical diagnoses. With the fast development of the retrieval of the image based on content, the technology of the detection of the symmetry becomes perfect step by step, so that it can be applied in sweeping areas.This paper focuses on the principal problems in symmetry detection such as the selection of the symmetric points in image and the location of reflectional symmetry axes and deeply research in them. Firstly, by imitating human brains’ visual characteristic and applying the information of the phase, we find a measure of symmetry base on wavelet transform computed by phase congruency function, based on which we can choose the areas of symmetry in images. Secondly, in order to find the location of symmetry axes in the images, we compute the orientation histogram of the local energy gradient. Lastly, we extend the method to deal with an order of images with symmetric object. The results of the experiment can find different diatoms images with different orientation and number symmetry axes, and retrieve them by symmetry detection. We estimate detection of symmetry has a broad practicability.The software in the paper is programmed with Matlab 5.2,debugged successfully on IBM PC 586(400MHZ). The used images in the paper are 8 bit gray images. The method in this paper could be well applied in the application of retrieval of the images based on content.更多还原