Phase-based stereo matching using epipolar line rectification

Projected grating phase method with two-camera setups uses phase values to set up the corresponding points between the left and right images. For solving the problem of a lower speed in the traditional phase-based stereo matching method, a new phase-based stereo matching method using epipolar line rectification is presented to improve the speed of phase-based stereo matching. Firstly, the epipolar line rectification algorithm is used to transform the bi-stereo geometry into the epipolar standard geometry. That is, the epipolar line for a certain point on the left image is simply the horizon line with the same row coordinate on the right image. Then, based on the epipolar line rectifications of left and right phase maps, procedures of improved phase-based stereo matching method are presented. Finally, through three-dimensional reconstruction of certain objects, this paper analyses and compares the performances of original and improved phase-based stereo matching methods. The experimental results show that the improved method has shortened the matching time by 63 percent as compared with that of traditional method. The method can meet the requirements of high speed for industrial measurements.