An improved watershed algorithm based on multi-scale gradient and distance transformation

Cell image segmentation is an important step in medical image processing and analysis system. The watershed algorithm is usually used to segment cells in the image. However, it is difficult to segment touched cells. Traditional watershed algorithms, based either on a distance map or on a gradient map, easily result in over-segmentation because they only consider location information or edge information of a pixel in an image. In this paper a top/bottom transformation is used to enhance an image, a combined transformation on multi-scale gradient and distance is proposed, and then the watershed algorithm is used to segment cell images. The improved algorithm can reduce the influence of noise, and give good results when segmenting cells in series and interlink because it includes both location and edge information.