As an example, consider inspection of an object by a stereo head. We define the head position as the midpoint of the line connecting the optical centres of the cameras.
The stereo visibility algorithm takes as input a portion of the property sphere describing a visibility region (of a feature or set thereof), in which every viewpoint is weighted by an optimality coefficient encoding both visibility and reliability of inspection (notice that such a region may not be maximally connected).
The output of the algorithm is an ordered list of head positions
( c1 ,.....,ck ), ci = ( Vil , Vir ) ,
where ( Vil , Vir ) , are the viewpoints of the left and right cameras.
The global complexity of the stereo positioning algorithm is R(O (F) + O(RC)) = O(RF) + O(R2 C), where R is the number of viewpoints in the visibility region, C is the number of viewpoints at a fixed
distance from a given one (a function of the dome's resolution), and F is the number of viewpoints on the geodesic dome. If O(F) < O(RC), the complexity becomes O(R2 C). Figure 15, below, shows (shaded) the optimum position for
a stereo head of baseline 400mm to inspect the planar face on the bottom side of the object, nearest the viewer, having the inverted `V' bounding contour. The focal length of the cameras was 20mm, the dome radius 1376mm. The stand is about 16cm tall. This solution was found in about two seconds.
Figure 15: Example of stereo head positioning
[ Computing and using inspection-oriented VCRs |
Path planning ]
Comments to: Sarah Price at ICBL.