A Two-stage Segmentation Algorithm Using Robust Anisotropic Region Growing

Region growing is a widely used image-segmentation techniques. However, oversegmentation and dependency on the starting point (seed) pose difficulties. We propose au algorithm using the robust homogeneous criteria consisting of (1) intensity and (2) no edge in-between criterion. The region is grown into pixels that satisfy both criteria. The intensity criterion ensures that no abrupt. change occurs in the image intensity inside a region. It is calculated based on the local average image intensity after rejecting outliers. The no edge in-between criterion prevents the growing across the boundaries. The segmentation algorithm consists of a (1) coarse and a (2) fine scaled segmentation. In the first stage, large regions are segmented, which include both uniform regions and regions containing a small area of intensity fluctuation. In the second stage, the remaining regions are segmented. Our experiments showed good segmentation results for both gray-scale and color images.