We next show the results from the computation of time-to-contact to curved surfaces. Fig. 5 (a) shows five sequential images of a head observed from a translating camera, and Fig. 5 (b) shows their contour curves extracted by B-spline fitting. The frontier points and the epipolar lines are extracted from the bi-tangency of apparent contours, and are shown in Fig. 5 (b). The time-to-contact to the frontier point (upper frontier point) is computed, and is shown in Fig. 5 (c) by small circles and solid lines. The exact time-to-contact is shown by dotted lines in (c). As shown in this figure, the computed time-to-contact is quite accurate and reliable.
Figure 5:
Results of the computation of the time-to-contact. (a) shows sequential
images of a head. (b) shows the extracted contour curves (solid lines),
frontier points (small circles) and the epipolar lines (dashed lines).
(c) shows the computed time-to-contact to the frontier point (solid
lines) together with the calibrated time-to-contact (dashed lines).
J. Sato