Seamline Determination for High Resolution Orthoimage Mosaicking Using Watershed Segmentation

Image mosaicking is a process during which multiple orthoimages are combined into a single seamless composite orthoimage. One of the most difficult steps in the automatic mosaicking of orthoimages is the seamline determination. This paper presents a novel algorithm that selects seamlines based on marker-based watershed segmentation. A representative seamline is extracted at the object level and the pixel level as follows. First, a watershed segmentation is performed to obtain the objects. To avoid over-segmentation, a regional adaptive marker-based watershed segmentation is proposed. Second, the object difference estimated by the correlation coefficient of each object is calculated, and the region adjacency matrix is built. Third, a technique for minimizing the maximum object cost is adopted to determine the objects through which the seamlines pass. Finally, pixel-level optimization is performed using Dijkstra's algorithm with a binary min-heap to determine the final seamlines. The experimental results on digital aerial orthoimages in different areas demonstrate the feasibility and effectiveness of the proposed method compared with other algorithms.