Acta Geodaetica et Cartographica Sinica ›› 2026, Vol. 55 ›› Issue (9): 1567-1581.doi: 10.11947/j.AGCS.2026.20260115

• Marine Surveying and Mapping • Previous Articles     Next Articles

Efficient interpretation algorithm for foreign nautical chart substrate annotations considering semantics and image features

Jian Dong1(), Chaoyu Tan1(), Lulu Tang1, Zeyuan Dai1, Tian Xie1, Changlin Chen2, Er Ni3   

  1. 1.Dalian Navy Academy, Dalian 116018, China
    2.Naval Research Institute, Tianjin 300450, China
    3.Troops 92403, Fuzhou 350000, China
  • Received:2026-04-09 Revised:2026-08-30 Online:2026-10-28 Published:2026-10-28
  • Contact: Chaoyu Tan E-mail:Navydj@163.com;19524744505@163.com
  • About author:Dong Jian (1985—), male, PhD, professor, majors in nautical chart compilation. E-mail: Navydj@163.com

Abstract:

In response to current issues in the automatic interpretation of foreign raster nautical chart substrate annotations, such as poor adaptability to complex scenarios, low efficiency, and the disconnection between semantics interpretation and image processing, this paper proposes an efficient interpretation algorithm for foreign nautical chart substrate annotations considering semantics and image features. Firstly, the algorithm constructs an image optimization strategy based on the visual representation features of substrate annotations. By applying land area masking and adaptive threshold segmentation, it effectively filters out interference from the complex background of raster charts. Subsequently, template matching technology is introduced to establish a substrate annotation template library based on Hu invariant moment features, achieving integrated interpretation for both character recognition and semantic parsing. Finally, to address the difficulty in constructing templates for composite annotations, a two-level annotation slice segmentation model considering semantic integrity is designed, solving the interpretation challenge of complex combined annotations. Experimental results show that: ①The proposed algorithm successfully achieves efficient interpretation of foreign chart substrate annotations, demonstrating high precision, recall, recognition completeness rate, and semantic accuracy during the processes of annotation recognition and semantic parsing.②Comparative experiments with existing methods under scenarios of varying complexity indicate that the proposed algorithm maintains higher recognition accuracy while further improving overall processing efficiency. Moreover, it effectively addresses issues of missed annotations and semantic parsing errors encountered by comparative methods in medium-and high-complexity scenarios, proving the superior robustness and efficiency of our approach.

Key words: nautical chart informatization, automatic extraction, substrate annotations, semantic parsing, template matching

CLC Number: