Sub-pixel matching with consideration of lens distortion

As a crucial part of active three dimensional(3D) vision system based on fringe projection technique, correspondence search between two adjacent range images would directly influence on the accuracy of matching and fusion procedure of the depth data. The conventional sub-pixel matching method by means of phase correlation can achieve a high level of accuracy while it would also be associated with a time consuming procedure due to the requirement of capturing two orthogonal series of sinusoidal fringes. Another technique utilizing linear interpolation algorithm based on the fringe projection with single direction might cause accuracy declination as a result of the simplification in imaging model. A novel method under the framework of linear interpolation was proposed. This approach makes use of absolute phase values and parameters of epipolar line as two kinds of feature points for correspondence search, leading to a significant improvement on the measurement accuracy of the depth data. Theoretical analysis and experiment results demonstrate the validity of presented approach.