Line Matching Algorithm Based on Pair-wise Geometric Features and Individual Line Descriptor Constraints

  Objectives  In the field of line matching and checking, the geometric attributes of the individual line are weakly stable, and the non one-to-one matching results are difficult to be checked. To address the problems above, a line matching algorithm based on pair-wise geometric features and individual line descriptor constraints was proposed.

  Methods  For matching process, first, two line segments which satisfied certain geometric constraints in the neighborhood were grouped into a line pair and matched as a whole. Second, the epipolar constraint of the intersection in the line pair was used to determine the matching range. And characteristic angles within line pairs, distance ratio between line segments and the radiation information of the neighborhood of line pairs were used to narrow the range of the matching candidates. Finally, the final matching pairs was obtained by calculating the gray similarity of triangle region. For checking process, initially according to the angle of line with epipolar and the slope of line, the corresponding relation between individual lines was established. Moreover, each corresponding line pair was split into two groups of corresponding individual lines. Then, descriptors were established for two single lines in each group and the similarity between the two line descriptors was calculated. Eventually, collinear geometry and descriptor similarity were combined to check the matching results, eliminate the false matches. Collinear lines in the results were merged and one-to-one matching results were obtained.

  Results  Aerial images with typical texture features and close-range images of different transformation types were selected for experiments. The results demonstrate that the proposed algorithm has a high matching accuracy. The matching accuracy rate is higher than 95% in complex scenes with similar texture, perspective change, rotation change, scale change and illumination change.

  Conclusions  The proposed algorithm has good robustness to different types of images, and also has advantages for complex line matching check.