OTSU method is considered to be the best algorithm for image segmentation of threshold selection. It's very simple and it's regardless of image brightness and contrast effects. Therefore it has been widely used in digital image processing. However, in the actual image, because of the influence of noise etc., traditional OTSU algorithm cannot be obtained an accurate segmentation results. In this paper, we divide the CT images of the liver by the combination of the PM filter and local gray stretch. Then we get binary images of vascular. Finally we reconstruct the venous system in liver by the use of Visualization Toolkit (VTK) and 2D segmentation results.
