Dense Optical Flow Method for Intelligently Extracting Seamline of Orthophotos

  Objectives  Geometric misalignment is one of the key problems for orthophoto mosaicking. To solve this problem, this paper proposes a regional seamline detection algorithm based on dense optical flow.

  Methods  Firstly, the cost image is constructed with dense optical flow, gradient information and gray information. And the cost image is regarded as a weighted undirected graph. Secondly, the principle of maximum flow and minimum cut is used to search for seamline based on graph-cut model.

  Results  The experiment results show that the seamline cost of the sparse building area greater than 100 pixels obtained by the proposed method only accounts for 0.7% of the path length. And the search efficiency of the proposed method is increased by 17% compared with OrthoVista software.

  Conclusions  The proposed method can automatically avoid passing the building area and the areas with large projection in digital orthophoto map, greatly reduce the probability of geometric dislocation phenomenon of image mosaicking, and realize the intelligence of orthophoto seamline searching.