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: Drawing the stripe for automatic contour detection.
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.
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).
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.
3: Use of the Automatic Contour Detection tool to complete a contour.
See also: Overview, Contour Edition