A Stereovision Measurement Method Using Epipolar Constraint to Correct Digital Image Correlation Matching

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.