为了提高立体视觉方法的测量精度, 提出一种极线约束修正数字图像相关(DIC)匹配的立体视觉测量方法。该方法通过DIC方法获得立体匹配的初值, 应用极线约束对匹配计算结果进行修正, 取位于右极线上距DIC匹配结果最近的点作为新的匹配点, 并将该种匹配修正方法推广到右图像时序匹配。在材料实验机上完成304不锈钢试件单向拉伸实验, 以引伸计的测量结果为真值, 对比极线约束修正前后的双目立体视觉的测量误差。实验结果表明, 极线约束修正以后, 双目立体视觉测量误差的最大值、平均值及均方值均减小, 说明极线约束修正后的匹配方法可以提高立体视觉方法的测量精度。

To improve the measurement accuracy of stereovision method, a correction method based on epipolar constraint for digital image correlation (DIC) stereo matching is proposed. The initial stereo matching result is obtained by DIC method, and then the initial results are corrected by epipolar constraint. The point on the right pole line, which is the nearest to the initial result of DIC method, is selected as the new matching point on right image. In addition, this method is also used to match the sequential images. The tensile test of 304 stainless steel specimen is conducted on a material testing machine. Compared the measurement error of the proposed method with that of stereovision method without correction, the experimental results show that the maximum error, the average error and the root mean square value of the proposed method decrease through correction by epipolar constraint, which testifies that the proposed method can improve the measurement accuracy of stereovision method.