A fast minimal path active contour model
A new minimal path active contour model for boundary extraction is presented. Implementing the new approach requires four steps (1) users place some initial end points on or near the desired boundary through an interactive interface; (2) a potential searching window is defined between two end points; (3) a graph search method based on conic curves is used to search the boundary; and (4) a "wriggling" procedure is used to calibrate the contour and reduce sensitivity of the search results on the selected initial end points. The last three steps are performed automatically. In the proposed approach, the potential window systematically provides a new node connection for the later graph search, which is different from the row-by-row and column-by-column methods used in the classical graph search. Furthermore, this graph search also suggests ways to design a "wriggling" procedure to evolve the contour in the direction nearly perpendicular to itself by creating a list of displacement vectors in the potential window. The proposed minimal path active contour model speeds up the search and reduces the "metrication error" frequently encountered in the classical graph search methods e.g., the dynamic programming minimal path (DPMP) method.