Gradual Generalizations of Nautical Chart Contours with B-Spline Snake Methods
B-spline snake methods have been used in cartographic generalization in the past decade, particularly in the generalization of nautical charts where these methods yield good results with respect to the shoal-bias rules for the generalization of chart contours. However, previous studies only show generalization results at particular generalization (or scale) levels, and show only two states of the algorithm: before and after generalization, but nothing in between. This thesis presents an improved method of using B-spline snakes and other auxiliary functions and workflows for generalization in the context of nautical charts which can generalize multiple nautical chart features from large scale to small scale without creating any invalid intermediate features that require special processing to resolve. This process allows users to generate charts at any intermediate scale without cartographic irregularities, and is capable of extension to include more specialized generalization operators.
Dandan Miao is pursuing an M.S. in Ocean Engineering: Mapping Option. Dandan graduated with a B.S. in Geographic Information System from Wuhan University in 2009. She completed her senior thesis on “The 3D-Display of seafloor feature--The application of 3DGIS in electronic chart.” She comes to CCOM directly after graduating from her undergraduate university. She is an environmentalist and she likes dancing and other aerobic exercises.