Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (6): 1180-1194.doi: 10.11947/j.AGCS.2024.20230287

• Smart Surveying and Mapping • Previous Articles     Next Articles

Local clarity estimation and adaptive segmentation of line features based on positive and negative kernel density curves

Xiaoqiang CHENG1,2(), Na LIU1()   

  1. 1.Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
    2.Hubei Key Laboratory of Regional Development and Environmental Response, Wuhan 430062, China
  • Received:2023-07-14 Published:2024-07-22
  • Contact: Na LIU E-mail:carto@hubu.edu.cn;2983046051@qq.com
  • About author:CHENG Xiaoqing (1985—), male, PhD, associate professor, majors in geographic information visualization. E-mail: carto@hubu.edu.cn
  • Supported by:
    Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation, Ministry of Natural Resources(KF-2021-06-109)

Abstract:

In line simplification, segmentation of map line features according to differences in morphological features is the key to rational use of simplification methods. The existing segmentation methods are mainly based on vertices to analyze the morphological heterogeneity of line features and ignore the morphological changes of line features expressed at different scales. The fuzzy parts that cannot be clearly identified in the heterogeneous line features will change with the different scales. Based on this, a method for segmenting line features based on clarity changes is proposed in this paper. Firstly, the raster pattern of line features is generated at a specific scale, and the raster line pixels are classified into three types of pixels: single-boundary pixels, double-boundary pixels, and internal pixels; single-boundary pixels and internal pixels, which affect visual discrimination; the mapping relationship between the three types of pixels and the original vector line is established, and two groups of data points are obtained: adhesive vertices, which correspond to the blurred parts of the line features, and normal vertices, which correspond to the clear parts of the line features; and the aggregation analysis of the two groups of data points based on the kernel density, and the clustering analysis is generated, and generate the positive kernel density curve which indicates the change of line feature clarity and the negative kernel density curve which indicates the change of line feature blurring degree under this scale; finally, analyze the characteristics of the intersection of two kernel density curves to get the segmentation point which divides the clarity and blurred parts of the line feature and complete the segmentation of the line. By comparing the segmentation results with manually segmented results, it is evident that the segmentation results of this paper are generally consistent with the human eye's identification of fuzzy and blurred parts of the line features.

Key words: multiscale, heterogeneous line features, local clarify, kernel density estimation, line features segmentation

CLC Number: