Improved External Force Field for Snakes and Accurate Segmentation of Left Ventricle MRI
Shi Cheng-xian, Wang Ping-an · Journal of Nanjing University of Science and Technology · 2006
Parametric active contour model(Snakes) manifests two limitations: an initial contour must be set near the feature of the image and such a model cannot deal properly with the concave regions in the image.By replacing the gradient field with the gradient vector flow(GVF),Snakes can segment concave region edges effectively and has a large capture range.GVF Snakes has poor performances at high curvature boundaries(such as corners) due to the smoothness of the intrinsic force and the gradient vector flow.The image is smoothed by an anisotropic diffusion equation.The combination of the gradient vector force field with the potential force field is proposed for Snakes.Experiments demonstrate that the model curve is driven accurately to the object boundary by the new forces even if the initial estimate curve is not close,the object is nonconvex or the edge has a high local curvature on the left ventricle MRI.