【作者】 祁俊；

【导师】 李明；

【作者基本信息】 兰州理工大学 ， 通信与信息系统， 2012， 硕士

【摘要】 人脸识别是计算机视觉研究领域的一个热点问题,并广泛应用于视频监控、门禁系统以及公安系统等领域。本文把混沌理论和人工鱼群算法引入进来,对由LDA变换后的特征空间进行优化搜索,选择出高效低维的人脸鉴别特征,并在此基础上利用MATLAB软件进行仿真实验,验证该方法的正确性和有效性。主要研究工作总结为以下两点：(1)针对人工鱼群算法易陷入局部最优的问题,提出了一种基于双混沌映射的人工鱼群算法。该方法利用混沌的随机性、遍历性和规律性对人工鱼算法进行改进：一是初始化人工鱼群,增加搜索的多样性；二是在人工鱼陷入局部最优时,对其产生扰动,使其跳出局部最优值,向全局最优值靠近。仿真实验表明：改进后的算法比基本人工鱼群算法的全局寻优能力更强,搜索效率更高。(2)针对LDA算法无法找到最优分类特征子空间的问题,提出一种基于混沌人工鱼群的LDA算法。该方法把经过LDA算法变换后的特征子空间作为搜索空间,充分利用混沌人工鱼群算法的全局寻优能力,在特征子空间进行优化选择,获得最有利于分类的特征了空间。仿真实验结果表明：混沌人工鱼群与LDA算法的结合,有效地改善了LDA算法在特征向量选择中的局限性,从而提高了识别率。综上所述,混沌理论、人工鱼群与LDA相结合的方法,对人脸识别中的特征提取与选择具有正确性和高效性,为人脸识别的后续研究奠定了良好的研究基础。更多还原

【Abstract】 Face recognition technology has been the active field of computer vision, image processing and patern recogniton. After serval decades rapid development, it has been widely applied to surveillance and security, human-computer intelligent interaction, video meeting and so on.This paper persents the method of the feature extraction and selection of face image based on Linear Discriminate Analysis(LDA). The task is the optimization combination of the feature vectors in the feature space after LDA transform by the improved artificial fish school algorithm(AFSA) based on chaos theory. The main task is as follows:Firstly, a CAFSA algorithm based on chaos theory is presented to resolve the problems of AFSA, such as poor performance of precision and low rate of convergence. Initializing population of fish with the chaos increases the diversity of fish and the chaos search makes fish to get rid of local minima and improve the efficiency. The simulation experiments show that the proposed method has more effective perfomances and robustness.Secondly, LDA fails to find the optimalest feature subspace for face classification in certain circumstances. Aiming at this problem, an improved LDA algorithm based on CAFSA is proposed in this paper. The novel method LDA-CAFSA selects the best feature from the feature subspace transformed by LDA through the stochastic global optimization ability of the CAFSA. The simulation experiments show that the proposed method is stronger than the basic LDA.As is stated, the chaos theory and AFSA algorithm with a combination of LDA method is accuracy and credibility algorithm in the extraction and selection of feature space. And this laids a good foundation for the follow study on the face recognition.更多还原