Automatic contour detection

This feature detects the contour of an object in a semi-automatic way. To use this tool, open the desired slice and then select the Automatic Contour Detection tool  from the Toolbar. If this have not been done yet, create a new contour in the Object Explorer (see Add Contour) and make sure it is selected in the Object Explorer. A partially defined contour can be selected and extended using this tool. Then, click on the image and keep the left button pressed while moving the mouse to draw a stripe that covers the contour to be detected as shown in Figure 1.

Figure 1: Drawing the stripe for automatic contour detection.

Once the stripe is drawn on the desired contour, release the mouse and the contour will be detected automatically. BioVis3D searches for the best contour fit within the region delimited by the stripe, if the default stripe width is not appropriate for the user, a different width can be selected from the Toolbar (see Stripe width). It is important to be aware that the contour detection process is only affected by the region covered by the stripe and not by the way it is drawn, i.e., the speed and smoothness of the mouse movements do not affect the result.

Figure 2: Example of a contour detected automatically.

The result of this operation is a contour, defined by several nodes as shown in Figure 2. If necessary, these nodes can be manually adjusted to better fit the image  (see Contour Edition for details).

If the starting and closing ends of the drawn stripe overlap, the resulting contour will be automatically tagged as closed (see Closed property in Contour Properties). Otherwise, close the contour manually by selecting the value True in the property named Close in the Property Panel or repeat the automatic detection procedure previously described to extend the contour until there is a closed contour as sown in Figure 3. Make sure every contour is closed before attempting to build a 3D reconstruction of the object.

Figure 3: Use of the Automatic Contour Detection tool to complete a contour.

See also: Overview, Contour Edition