改进的基于弦切变换的目标检测方法  

Improved method of object detection based on chord-tangent transformation

作　　者：何莲[1,2] 蔡敬菊[1] 张启衡[1] 

机构地区：[1]中国科学院光电技术研究所,四川成都610209 [2]中国科学院研究生院,北京100049

出　　处：《红外与激光工程》2012年第1期239-247,共9页Infrared and Laser Engineering

基　　金：国家863计划(2002AA2Z9999;2004AA99)

摘　　要：在计算机视觉中形状是目标识别和检测的重要特征,针对目前许多基于形状特征的检测方法信息不够丰富,容易受边缘缺损变形等方面的影响,不具有局部特性,尤其是在许多复杂环境下很难实现对目标的正确检测等不足,提出了一种基于弦切变换理论在有限的目标边缘点信息基础上提取几何形状特征及相应的目标检测方法。该特征具有平移、旋转以及缩放不变性,基于此特征进行的目标检测能有效的得到目标的中心位置以及相关的二维运动参数,即使在一些复杂环境以及目标边缘部分失真或缺损的情况下也具有一定的鲁棒性。但由于边缘本身容易受到图像质量、对比度以及量化误差等影响,从而影响算法的精度。因此,文中通过融合丰富的灰度信息,使表征目标的特征更加丰富和完善,在形状和灰度的共同约束下提高检测的正确率和精确性。通过对多组图像序列进行仿真实验,结果表明了算法的有效性,及其在准确性和精确性上的提高,改进后待测目标与模板之间的匹配率可达90%以上。Shape is a kind of important feature to detect or recognize objects in computer vision.However,some disadvantages still exist in many methods based on shape feature at present,such as having no abundant information,easily affected by the default and distortion of edge,or having no local property.Especially,it is very difficult to detect object correctly under some complicated environments.In order to overcome these defects,a kind of shape feature extracted by using the chord-tangent transformation and corresponding algorithm of target detection was presented in this paper,which was obtained according to the finite edge point.This geometric feature had the invariant character of translation,rotation and scale.Some important parameters about movement including the location of object could be obtained through this method,even under some complicated environments.However,because the edge extraction is usually affected by the quality of image,contrast between the object and background and quantized error,the precision can be decreased.Therefore,some gray information was added to the feature in order to improve the algorithm.Finally,experimental results indicate the effectivity of the algorithm.The matching rate between the object and model can be extended to more than 90% after improving.

关 键 词：弦切变换 几何特征 特征匹配 参数估计 目标检测 

分 类 号：TP317.4[自动化与计算机技术—计算机软件与理论]