Figure 6.

The contribution of the ground plane to the distribution of the physical sources of differently oriented intervals. (A) Physical intervals on the ground plane (colored lines) that extend further and further away from the image plane will project more and more vertically (see corresponding colored lines). (B) Intervals were sampled from two distinct subsets of the image database, one without the ground plane and the other with the ground plane being the predominant component. The mean φ of the physical intervals in each of these samples is plotted as a function of θ. The function obtained from the entire image database (Fig. 5B) is included for comparison. (C) The mean of the physical length-to-projected length ratio (λ) of the intervals in each of the samples plotted as a function of θ.