The active contour interactive software

The active contour software was originally developed in a C++/Tcl-Tk environment for segmentation of 3D ultrasound data and later adapted for segmentation of MRI/CT images. This section gives a brief description of the second version.

The version for MRI/CT images can read the binary format of the VHP images directly. The following two windows constitute the main user-interface (click on any of them for a full sized version):
1. The first window shows the original image and has the following functionalities:
  • add : Add a polygon by marking a region of interest on the image, clicking the first mouse button at every point on the image upon which you wish to place a vertex. Vertices are automatically connected by lines;
  • move polygon : Move an entire polygon to another location in the image;
  • move vertex : Move a vertex of a polygon to another location in the image. The original links of the polygon remain, i.e. the neighbouring vertices of the moved vertex are still the same;
  • deform : This causes the closed polygon in the image to become active and trying to settle down in a minimum according to the calculated energy of the image;
  • delete : Delete a polygon;
  • glue : Glue a vertex. A glued vertex will not move when the deform option is activated.
2. The second window shows the energy used to drive the active contour. The energy of the image is obtained by taking the gradient of the reciprocal of the gradient of a Gaussian convolved with the image:


The standard deviation of the Gaussian kernel can be varied in the range 1.0-10.0 pixels with the slider at the bottom of the window.


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