ment in this case, as the optical flow computations are
never perfect. Figure 2 shows the results. The parameters of the algorithm are the same as those used in section 3.1. We see that, as before, the alteration is detected
for the compositing using two cameras whereas it is not
when the compositing was done using only one camera,
as expected. The influence of motion may particularly
be observed at edge locations, and is at the origin of the
differences between these results and those in figure 1.