This paper proposes a hierarchical method of image segmentation with topological adaptability

called B spline active contour based on edge detector. Unlike traditional method of active contour

our method takes region homogenous property into account and designs a new external force regional force

which is very robust to noise contamination. Also

internal force is integrated into the B spline. Our method is composed of two steps. First step is a kind of low level image segmentation. In this step

a local edge detector is used for detecting all edge points of the image. Second step is a kind of high level image segmentation. In this step

our B spline active contour based on the global image statistic is used for refining the region boundary. Also

we propose a new topology adaptability method

which is based on the change of region Euler number. Our method requires less interactive operation and is insensitive to initial condition. The experiments reported in the paper

performed on real images

confirm that the method can offer a good segmentation result and it has a very good topological adaptability.