Applications to Industrial Quality Inspection - 3D Computer Vision: Efficient Methods and Applications - page 266

Fig. 6.24 Three-dimensional reconstruction results for ( a ) the connection rod, ( b ) the star pattern,
and ( c ) the ring-shaped flange. The images in the left column display the results obtained based
on intensity and polarisation angle as photometric information, while for the images in the right
column the polarisation information was neglected
the two images that initially only one single stereo point can be determined. 1 In the
flange example, the brightness distribution across the surface is also fairly different
for the stereo images, but the appearance of the surface is sufficiently similar to
obtain initial three-dimensional points for about 10 % of the image pixels situated
on the ring section.
Figure 6.24 shows the final three-dimensional reconstruction results for the three
regarded examples. In each case, the three-dimensional profile obtained using po-
1 In all experiments, the same blockmatching threshold was used. Slightly decreasing this threshold
for the star pattern example would have resulted in more than one initial three-dimensional point.
However, this somewhat extreme configuration was used intentionally in order to illustrate that this
information is sufficient to obtain convergence of the specular stereo scheme.