The VB implementation of contour detection and extraction for CT images of knee joint

In clinical medicine, CT (Computerized Tomography) scanning is often carried out on parts of the human body with pathological changes, in order to diagnose and treat disease. When it is needed to establish a model of different parts for human body, related data of establishing model could be obtained through the scanned images. In this paper, the contour detection and extraction for CT images of knee joint are implemented through the designed VB (Visual Basic 6.0) program. The detective algorithms for contour include: first-order and second-order differential operators. The image processing effects of the differential operators with horizontal and vertical direction are better than operators with single direction. The chain code method is adopted for contour extraction, and pixels information on the image contour is saved. Through this designed program it provides the foundation for independent development of digital image processing program and from 3d medical images to the three dimensional geometric model building.