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Examples

As an example a rectified image pair from the Arenberg castle is shown for both the standard rectification and the new approach. Figure 7.8 shows the original image pair and Figure 7.9 shows the rectified image pair for both methods.

Figure 7.8: Image pair from an Arenberg castle in Leuven scene.
\begin{figure}\centerline{
\psfig{figure=stereo/kasteel.026.ps,width=4cm}
\psfig{figure=stereo/kasteel.027.ps,width=4cm}
} \end{figure}
Figure 7.9: Rectified image pair for both methods: standard homography based method (top), new method (bottom).
\begin{figure}\centerline{
\psfig{figure=stereo/kasteel.26.rectold.ps,width=4cm...
...s,width=4cm}
\psfig{figure=stereo/kasteel.27.rect.ps,width=4cm}
} \end{figure}

Figure 7.10: Image pair of the author's desk a few days before a deadline. The epipole is indicated by a white dot (top-right of 'Y' in 'VOLLEYBALL').
\begin{figure}\centerline{
\psfig{figure=stereo/MPdesk.1.epi.ps, width=4cm}
\psfig{figure=stereo/MPdesk.2.epi.ps,width=4cm}
} \end{figure}
Figure 7.11: Rectified pair of images of the desk. It can be verified visually that corresponding points are located on corresponding image rows. The right side of the images corresponds to the epipole.
\begin{figure}\centerline{
\psfig{figure=stereo/MPdesk.1t.rect.ps, height=10cm}
\psfig{figure=stereo/MPdesk.2t.rect.ps, height=10cm}
} \end{figure}
Figure 7.12: Raw and interpolated disparity estimates for the far image of the desk image pair.
\begin{figure}\centerline{
\psfig{figure=stereo/MPdesk.rawdisp.ps, width=3.2cm,...
...}
\psfig{figure=stereo/MPdesk.disp.ps, width=3.2cm, height=8cm}
} \end{figure}
A second example shows that the method works properly when the epipole is in the image. Figure 7.10 shows the two original images while Figure 7.11 shows the two rectified images. In this case the standard rectification procedure can not deliver rectified images.

A stereo matching algorithm was used on this image pair to compute the disparities. The raw and interpolated disparity maps can be seen in Figure 7.12. Figure 7.13 shows the depth map that was obtained. Note from these images that there is an important depth uncertainty around the epipole. In fact the epipole forms a singularity for the depth estimation. In the depth map of Figure 7.13 an artifact can be seen around the position of the epipole. The extend is much longer in one specific direction due to the matching ambiguity in this direction (see the original image or the middle-right part of the rectified image).

Figure 7.13: Depth map for the far image of the desk image pair.
\begin{figure}\centerline{
\psfig{figure=stereo/MPdesk.depth.ps, width=6cm}
} \end{figure}


next up previous contents
Next: Stereo matching Up: Image pair rectification Previous: Transferring information back   Contents
Marc Pollefeys 2002-11-22