Rotation binocular stereo rectification algorithm based on hierarchical spatial consistency
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摘要:
在旋转双目立体视觉系统中,转台机械间隙导致的左右相机旋转平移偏差,造成立体校正图像的严重畸变。针对该问题,提出一种基于分层空间一致性的旋转双目立体校正算法。采用ORB特征在原始左右图像中进行快速全局立体匹配,设计一种新的特征点全局双层约束,实现匹配点的优选。提出基于内点邻域空间一致性的局部校验方法,实现二次匹配优化,并利用质量排序的优化匹配点集,由八点法基础矩阵估计算法计算左右相机的精确位姿关系,以此完成图像的立体校正。在Oxford和SYNTIM数据集上的典型算法对比实验,验证了所提算法的性能。多角度立体校正实验表明:所提算法可适应光轴夹角变化,在双目最大45°夹角时保证立体校正的质量,匹配点偏差小于0.2像素。
Abstract:The mechanical gap of the turntable in the rotating binocular stereo vision system causes the left and right cameras to rotate and deviate in translation, severely distorting the stereo rectification image. To solve this problem, a rotating binocular stereo rectification algorithm based on hierarchical spatial consensus is proposed. Firstly, oriented FAST and rotated BRIEF (ORB) features are used for the fast global stereo matching in the original images, and a new global double-layer constraint of feature points is defined to realize the preferred selection of the matching points. Then, a local verification method based on the consensus of the neighborhood space of the inliers is proposed to realize the secondary matching optimizations and the matching points are optimized by quality sorting. To finish the stereo rectification of the pictures, the eight-point method-based fundamental matrix estimation algorithm determines the precise pose relationship between the left and right cameras. The comparison experiments of typical algorithms on Oxford and SYNTIM datasets verify the proposed algorithm's performance. The multi-angle stereo rectification experiment shows that the proposed algorithm can adapt to the change of optical axis angle, and ensure the quality of stereo rectification when the maximum angle of binocular is 45°. The deviation of the matching point is less than 0.2 pixels.
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Key words:
- stereo rectification /
- rotating camera /
- fundamental matrix /
- spatial consensus /
- pose estimation
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表 1 匹配点分层优选和优化
Table 1. Hierarchical selection and optimization of matching points
图像 初始匹配点数 匹配点优选点数 二次匹配优化点数 Graf 400 175 125 表 2 立体校正精度统计
Table 2. Stereo rectification accuracy statistics
像素 校正
图像EH EM EV BF LM-RANSAC GC-RANSAC 本文 BF LM-RANSAC GC-RANSAC 本文 BF LM-RANSAC GC-RANSAC 本文 Building 7.4649 3.4254 3.1222 0.72 1.4629 0.4515 0.50001 0.1546 2.1609 1.2011 1.22001 0.4501 Baballe 24.4806 5.3412 5.9917 1.20001 3.2711 0.7122 0.6215 0.2056 4.4922 1.5522 1.3271 0.5132 Graf 4.728 2.5999 3.3781 0.7991 1.5077 0.4512 0.3189 0.1921 2.32 0.6801 0.6674 0.2312 Sport 212.004 12.1162 14.5999 3.33 89.3941 3.2433 2.6485 0.4975 86.458 4.1167 3.7247 1.2898 NBuste 234.3337 25.1242 22.5441 18.5327 111.9321 4.2311 2.0577 2.2262 139.2001 5.6822 3.8501 4.1999 -
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