With finer spatial scale, high-resolution images provide complex, spatial, and massive information on the earth's surface, which brings new challenges to remote sensing segmentation methods. In view of these challenges, finding a more effective segmentation model and parallel processing method is crucial to improve the segmentation accuracy and process efficiency of large-scale high-resolution images. To this end, this study proposed a minimum spanning tree (MST) model integrated into a regional-based parallel segmentation method. First, an image was decomposed into several blocks by regular tessellation. The corresponding homogeneous regions were obtained using the minimum heterogeneity rule (MHR) partitioning technique in a multicore parallel processing mode, and the initial segmentation results were obtained by the parallel block merging method. On this basis, a regionalized fuzzy c-means (FCM) method based on master-slave parallel mode was proposed to achieve fast and optimal segmentation. The proposed segmentation approach was tested on high-resolution images. The results from the qualitative assessment, quantitative evaluation, and parallel analysis verified the feasibility and validity of the proposed method.Remote Sens. 2020, 12, 783 2 of 29 high-resolution images. The abundant spatial and geometric information, which determines the spatial and geometric models, must be taken into account in building the segmentation model.Having massive data makes data the decomposition-based parallel algorithm a realistic choice to solve the complexity of computing time, and this approach has become one of the most effective ways to expand and optimize existing segmentation methods to address the massive remote sensing image processing requirements [11]. Many researchers have proposed various parallel image segmentation methods for large-scale high-resolution images [12][13][14]. For example, Xing et al. [15] proposed a parallel remote sensing image segmentation method combined with decomposition/merging mode and k-means algorithms based on geospatial cyberinfrastructure (GCI). Under this mode, the large-scale image is decomposed into several blocks, which are parallel-divided into regions. The merging process restores the block segmentation outcome to the whole image segmentation result and considers the merging of boundary region between blocks, which solves the problem of over-segmentation caused by decomposition. However, the k-means segmentation algorithm only considers spectral information and not the spatial and geometric information, resulting in difficulties in solving the complexity of high-resolution images.As a branch of mathematics, graph theory uses the graph as the primary study object and has the ability to describe the internal relations of vertex sets [16][17][18][19]. The remote sensing image representation model is built by mapping the coordinates and spectral information of the pixels into vertices. The adjacency relationship of the pixels is regarded as the connected edges between the vertices, whi...