A changeable moving step method based on level set algorithm

Level set algorithm (LSA) is one of the efficient tools of edge detection and contour extraction, which has been applied to medical radar and other images processing successfully. However, the process procedure using LSA will cost a lot of time when applied to high-resolution images. This paper provides a novel approach that can enhance the detection speed by changing the moving step of the contour in LSA dynamically. The moving step enlarges when the contour is far from the real boundary of specific targets, while the moving step reduces when the contour is near the real boundary in the image. Experimental results using Radarsat ScanSAR images show the effectiveness of this new method and verify the improved velocity in contour detection compared with the standard LSA.