Automatic Tie Points Extraction with Uniform Distribution and High Precision

• Main Authors: YU Ying, ZHANG Yongsheng, XUE Wu, LI Lei
• Format: Article
• Language: zho
• Published: Surveying and Mapping Press 2017-01-01
• Series: Acta Geodaetica et Cartographica Sinica
• Subjects: tie points extraction; SIFT; block; union-find set; least squares matching
• Online Access: http://html.rhhz.net/CHXB/html/2017-1-90.htm
• ISSN: 1001-1595; 1001-1595

To solve the problem of matching errors, redundant points with bad distribution,and low points position precision in photogrammetry aerial triangulation,an automatic tie points extraction with uniform distribution and high precision is presented. Firstly, Block SIFT technology is conducted on every image, then an unordered feature tracking method based on union-find set is adopted to detect the multi-view correspondences. Secondly, by using the proposed algorithm of points selection in object block space, the relatively balanced points are obtained. Finally, the precision of the image coordinates are improved by least square matching.In the experiment part,Songshan images and desert images are used to test the proposed method. Through the examination and analysis of three indicators, the visual inspection, back projection errors in image space,and the precision of check points, the results show that the proposed method can effectively overcome the difficulties in extracting and matching tie points caused by weak texture and repeated texture, enhance the uniformity of tie points distribution, and improve the position precision of tie points.