Journal cover Journal topic
Proceedings of the ICA
Journal topic
Volume 1
Proc. Int. Cartogr. Assoc., 1, 121, 2018
https://doi.org/10.5194/ica-proc-1-121-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Proc. Int. Cartogr. Assoc., 1, 121, 2018
https://doi.org/10.5194/ica-proc-1-121-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

  16 May 2018

16 May 2018

A Novel Method for Reconstructing Broken Contour Lines Extracted from Scanned Topographic Maps

Feng Wang1, Pingzhi Liu1, Yun Yang1, Haiping Wei2, and Xiaoya An1 Feng Wang et al.
  • 1Xi’an Research Institute of Surveying and Mapping, Xi’an, Shan’xi, China, China
  • 2Zhengzhou Institute of Surveying and Mapping, Xi’an, Shan’xi, China

Keywords: scanned topographic maps, broken contour lines, reconstruction, points’ auto-matching

Abstract. It is known that after segmentation and morphological operations on scanned topographic maps, gaps occur in contour lines. It is also well known that filling these gaps and reconstruction of contour lines with high accuracy and completeness is not an easy problem. In this paper, a novel method is proposed dedicated in automatic or semiautomatic filling up caps and reconstructing broken contour lines in binary images. The key part of end points’ auto-matching and reconnecting is deeply discussed after introducing the procedure of reconstruction, in which some key algorithms and mechanisms are presented and realized, including multiple incremental backing trace to get weighted average direction angle of end points, the max constraint angle control mechanism based on the multiple gradient ranks, combination of weighted Euclidean distance and deviation angle to determine the optimum matching end point, bidirectional parabola control, etc. Lastly, experimental comparisons based on typically samples are complemented between proposed method and the other representative method, the results indicate that the former holds higher accuracy and completeness, better stability and applicability.

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