External forces for active contours via multi-scale vector field convolution

In this paper we present a new method to generate the external force field for the active contour. The new approach, multi-scale vector field convolution (MVFC), is based on the vector field convolution (VFC) method, and extends VFC to a multi-scale process. Via automatic scale selection, the proposed method constructs the external force field used by the active contour by varying the convolution kernel width according to local image structure. The result is an adaptive force generation method that accommodates detailed, high curvature features with a large capture range, and demonstrates improved performance in terms of local convergence and multi-target segmentation over traditional VFC. Meanwhile, the new method preserves the low computation complexity as supported by VFC and exemplifies as a more efficient force generation method than gradient vector flow (GVF). Synthetic and real experiments demonstrate the efficacy of MVFC in terms of detail preservation, capture range, noise resilience and computational cost.