海陆影像分割对于后续的海岸线提取、潮间带地形反演、海岸演化状况分析等都具有十分重要的意义。本文在分析了四叉树、测地线活动轮廓(GAC)模型和Canny边缘检测算子等在海陆影像分割中优缺点的基础上,提出了一种四叉树、Canny算子和GAC模型相结合的海陆影像分割方法。该方法综合利用上述各方法的优点,将Canny算子边缘检测结果融入到基于四叉树初分割的GAC模型中,重构边界停止函数,演化水平集方程,实现海陆影像分割。试验结果表明,该方法具有海陆影像分割速度快、精度高、可靠性强和自动化程度高等优点,对于弱边缘以及严重凹陷边缘,都能实现自动和准确分割。
Island and coastal image segmentation is of great importance for the subsequent coastline extraction, terrain inversion for intertidal zone, analysis of the situation for shore evolution, and so on. Firstly, the advantages and disadvantages of quadtree, geodesic active contour (GAC) model and Canny edge detector used in the island and coastal image segmentation are analyzed. Secondly, an island and coastal image segmentation method is proposed by integrating quadtree, GAC model and Canny edge detector. The advantages of these three kinds of method are taken in the method proposed in this paper. The method introduces the results of Canny edge detector into edge indicator function of geodesic active contour model based on quadtree segmentation, evolutes the level set equation, and realizes island and coastal image segmentation.The experimental results show that the method proposed in this paper is of high speed, precision, reliability and automation for island and coastal image segmentation, even in the weak edges and serious concave edges.
[1] LIU H, JEZEK K C. Automated Extraction of Coastline from Satellite Imagery by Integrating Canny Edge Detection and Locally Adaptive Thresholding Methods[J]. International Journal of Remote Sensing, 2004, 25(5): 937-958.
[2] ZHANG Hongwei,ZHANG Baoming,GUO Haitao,et al. An Automatic Coastline Extraction Method Based on Active Contour Model[C]//Proceedings of the 21st International Conference on Geoinformatics. Kaifeng: IEEE, 2013: 111-115.
[3] NIEDERMEIER A, ROMANEESSEN E, LEHNER S. Detection of Coastlines in SAR Images Using Wavelet Methods[J]. IEEE Transactions on Geoscience and Remote Sensing, 2000, 38(5): 2270-2281.
[4] RYU J H, WON J S. Application of Neural Networks to Waterline Extraction in Tidal Flat from Optic Satellite Images[C]//Proceedings of IEEE International Geoscience and Remote Sensing Symposium (IGARSS). Toronto: IEEE, 2002, 4: 2026-2028.
[5] DING Xianwen, NUNZIATA F, LI Xiaofeng, et al. Performance Analysis and Validation of Waterline Extraction Approaches Using Single-and Dual-polarimetric SAR Data[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2015, 8(3): 1019-1027.
[6] 沈琦, 汪承义, 赵斌. 几何活动轮廓模型用于高分辨率遥感影像海岸线自动提取. 复旦学报(自然科学版), 2012, 51(1): 77-82, 104. SHEN Qi, WANG Chengyi, ZHAO Bin. Automatic Waterline Extraction in VHR Imagery Using Geometric Active Contour Model[J]. Journal of Fudan University (Natural Science),2012, 51(1): 77-82, 104.
[7] 申家双, 郭海涛, 李海滨, 等. 基于Canny算子和GAC模型相结合的影像水边线提取方法[J]. 测绘科学技术学报, 2013, 30(3): 264-268. SHEN Jiashuang, GUO Haitao, LI Haibin, et al. A Water Edge Extraction Method from Images Based on Canny Operator and GAC Model[J]. Journal of Geomatics Science and Technology, 2013, 30(3): 264-268.
[8] 沈芳, 郜昂, 吴建平, 等. 淤泥质潮滩水边线提取的遥感研究及DEM构建——以长江口九段沙为例[J]. 测绘学报, 2008, 37(1): 102-107. SHEN Fang, GAO Ang, WU Jianping, et al.A Remotely Sensed Approach on Waterline Extraction of Silty Tidal Flat for DEM Construction: A Case Study in Jiuduansha Shoal of Yangtze River[J]. Acta Geodaetica et Cartographica Sinica, 2008, 37(1): 102-107.
[9] NOAA, Shoreline Mapping. Silver Spring, MD, USA: NOAA, 1997[EB/OL]. [2015-05-03]http://anchor.ncd.noaa.gov/psn/shoreline.html.
[10] ZHANG Suoping, ZHANG Chuntian. Image Analysis for Wave Swash Using Color Feature Extraction[C]//Proceedings of the 2nd International Congress on Image and Signal Processing (CISP). Tianjin: IEEE, 2009: 1-4.
[11] QIN Ping. Waterline Information Extraction from Radial Sand Ridge of South Yellow Sea[C]//Proceedings of the 6th International Congress on Image and Signal Processing (CISP). Hangzhou: IEEE, 2013: 459-463.
[12] LI Heng, WANG Xinyu. Automatic Recognition of Ship Types from Infrared Images Using Support Vector Machines[C]//Proceedings of International Conference on Computer Science and Software Engineering. Wuhan: IEEE, 2008, 6: 483-486.
[13] BAGLI S, SOILE P. Morphological Automatic Extraction of Pan-European Coastline from Landsat ETM+ Images[C]//Proceedings of the 5th International Symposim on GIS and Computer Cartography for Coastal Zone Management. Genova: [s.n.], 2003.
[14] 孔丁科. 几何活动轮廓图像分割模型的研究[D]. 杭州: 浙江大学, 2010. KONG Dingke. Research on Geometric Active Contour Models for Image Segmentation[D]. Hangzhou: Zhejiang University, 2010.
[15] 孙颖, 张新长, 康停军, 等. 改进GAC模型在点云和影像自动提取建筑物边界中的应用[J]. 测绘学报, 2013, 42(3): 337-340, 350. SUN Ying, ZHANG Xinchang, KANG Tingjun,et al. Improved GAC Model for Automatic Building Extraction from LiDAR Point Clouds and Aerial Image[J]. Acta Geodaetica et Cartographica Sinica, 2013, 42(3): 337-343, 350.
[16] 戚世乐, 王美清. 自适应分割弱边缘的活动轮廓模型[J]. 山东大学学报(工学版), 2013, 43(6): 17-20. QI Shile,WANG Meiqing. Adaptive Active Contour Model for Weak Boundary Extraction[J]. Journal of Shandong University (Engineering Science), 2013, 43(6): 17-20.
[17] LI Chunming, XU Chenyang, GUI Changfeng, et al. Distance Regularized Level Set Evolution and Its Application to Image Segmentation[J]. IEEE Transactions on Image Processing, 2010, 19(12): 3243-3254.
[18] CASELLES V, CATTÉF, COLL T et al. A Geometric Model for Active Contours in Image Processing[J]. Numerische Mathematik, 1993, 66(1): 1-31.
[19] 欧阳越, 种劲松. 基于改进水平集算法的SAR图像海岸线检测[J]. 遥感技术与应用, 2004, 19(6): 456-460. OUYANG Yue, CHONG Jinsong. Coastline Detection Method in SAR Images Based on an Improved Level Set Algorithm[J]. Remote Sensing Technology and Application, 2004, 19(6): 456-460.
[20] 王相海, 金弋博. 高光谱海岸带区域分割的活动轮廓模型[J]. 中国图象图形学报, 2013, 18(8): 1031-1037. WANG Xianghai, JIN Yibo. The Active Contour Model for Segmentation of Coastal Hyperspectral Remote Sensing Image[J]. Journal of Image and Graphics, 2013, 18(8): 1031-1037.
[21] 朱述龙. 四叉树结构在数字图像分割中的应用[J]. 测绘学院学报, 1994, 11(1): 21-24. ZHU Shulong. The Application of Quadtree to Digital Picture Segmentation[J]. Journal of Institute of Surveying and Mapping, 1994, 11(1): 21-24.
[22] CANNY J. A Computational Approach to Edge Detection[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1986, 8(6): 679-698.
