US 12,340,486 B1
Method for determining seam line of orthoimages, method for generating mosaic image of orthoimages, device thereof, and medium thereof
Qingsong Wang, Guangdong (CN); Haisong Weng, Guangdong (CN); Ke Shi, Guangdong (CN); Tao Lai, Guangdong (CN); and Haifeng Huang, Guangdong (CN)
Assigned to SUN YAT-SEN UNIVERSITY, Guangzhou (CN)
Filed by SUN YAT-SEN UNIVERSITY, Guangdong (CN)
Filed on Nov. 11, 2024, as Appl. No. 18/943,847.
Application 18/943,847 is a continuation of application No. PCT/CN2024/104125, filed on Jul. 8, 2024.
Claims priority of application No. 202410642378.5 (CN), filed on May 23, 2024.
Int. Cl. G06T 5/50 (2006.01); G06T 7/13 (2017.01); G06T 7/64 (2017.01)
CPC G06T 5/50 (2013.01) [G06T 7/13 (2017.01); G06T 7/64 (2017.01); G06T 2207/20221 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for determining a seam line of orthoimages, comprising:
preprocessing orthoimages to obtain a master image and a slave image, wherein there is an overlapping area between the slave image and the master image;
extracting valid area contours of the master image and the slave image respectively through a crawling search method;
building a contour point lookup table based on a hash table and a list, and storing contour points of the valid area contours in the contour point lookup table; and
determining, through the contour point lookup table during an execution process of the crawling search method, whether a searched contour point is already located on a contour line from which the searched contour point is originated; and if yes, clipping the contour line;
determining intersection points of the respective valid area contours of the master image and the slave image;
acquiring an intersection contour of the master image and the slave image;
calculating difference values of valid pixels within the overlapping area between the master image and the slave image through a difference function, to obtain a difference map of the valid area; if there are more than two intersection points: calculating a position of a centroid of the overlapping area based on coordinates of each contour point of the intersection contour, determining a rectangular window centered on the centroid in the difference map, searching the rectangular window, and taking a position with a smallest difference value as an optimization end and the intersection points as optimization starts; and if there are two intersection points: taking the two intersection points as an optimization start and an optimization end, respectively; and
determining, based on the optimization start and the optimization end, a seam line of the master image and the slave image through an A* algorithm.