基于控制点和RGB向量差联合梯度Census变换的立体匹配算法  

Stereo Matching Algorithm Based on Control Points,RGB Vector Difference and Gradient Census Transform

作　　者：王森 危辉[1,2] 孟令江 WANG Sen;WEI Hui;MENG Lingjiang(Laboratory of Algorithms for Cognitive Modeling,School of Computer Science,Fudan University,Shanghai 200438;Shanghai Key Laboratory of Data Science,School of Computer Science,Fudan University,Shanghai 200438)

机构地区：[1]复旦大学计算机科学技术学院,认知算法模型实验室,上海200438 [2]复旦大学计算机科学技术学院,上海市数据科学重点实验室,上海200438

出　　处：《模式识别与人工智能》2022年第1期37-50,共14页Pattern Recognition and Artificial Intelligence

基　　金：国家自然科学基金项目(No.61771146)资助。

摘　　要：为了解决立体匹配算法在弱纹理区域及边界区域匹配精度较低的问题,文中提出基于控制点和RGB向量差联合梯度Census变换的立体匹配算法.首先,使用基于动态时间归整的行匹配算法,寻找最优匹配路径,经过扭曲对齐选取匹配特征点作为控制点.再使用基于RGB向量差代价联合基于梯度Census变换代价作为非控制点的匹配代价,基于梯度Census变换增加像素点的鲁棒性,RGB三向量保留图像三维色彩信息,使求得的代价精度更高.然后,融合求得的控制点与非控制点的匹配代价,作为初始匹配代价,基于RGB三向量差求得针对不同纹理区域的自适应窗口,在该窗口内以一次水平方向和竖直方向代价聚合的方式进行初始代价优化,同时使用多步骤优化减少视差错误率.最后,在Middlebury数据集上对不同区域测试视差错误率和在真实机器人场景上求取视差,将求得的视差利用三维成像原理进行三维重建测试.理论分析和实验表明,文中算法明显降低弱纹理区域和边界的误匹配率.Aiming at the low matching precision of weak texture region and boundary in traditional stereo matching algorithms,a stereo matching algorithm based on control points,RGB vector difference and gradient census transform is proposed.Firstly,a row matching algorithm based on dynamic time warping(DTW)is exploited to find the optimal matching path.The path is distorted and aligned to select matching control points.Then,RGB vector difference cost is combined with gradient Census transform cost as the matching cost of non-control points.The robustness of pixels is enhanced by gradient Census transform,and the three-dimensional color information of the image is retained by the RGB vector.Thus the higher matching precision is achieved.The combination of the matching cost of control points and non-control points is regarded as the initial matching cost.The RGB vector difference is utilized to acquire the adaptive window of different texture areas.The cost aggregation is calculated by the algorithm in a horizontal and vertical directions of an adaptive window.The cost aggregation is employed to optimize the initial cost.Multi-step optimization is employed to reduce the disparity error rate.Finally,the proposed algorithm is validated on Middlebury dataset for different regions and the disparity is calculated in the real scene of robot.The calculated disparity is verified for three-dimensional reconstruction based on the principle of 3D imaging.Both theoretical analysis and experimental results show that the proposed algorithm reduces the matching error rate of weak texture region and boundary significantly.

关 键 词：控制点 动态时间归整(DTW) 梯度Census变换 立体匹配 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]