Level crossing curvature and the Laplacian

摘要

Level crossing curvature is introduced as a basic description of an image, making it possible to detect edges and measure their curvatures at the same time. The relation between level crossing curvature and the Laplacian is derived, and this reveals that the Laplacian itself contains an edge curvature component. Using this, the location errors of the Laplacian are analysed as a method of detecting curved edges. The results show that level crossing curvature can cause location errors in the Laplacian, particularly when the edges have large curvature and small gradients.