Phantogram of a kitten
by JackDesBwa 2020-11-05 22:03
This semi-wild kitten was looking at me, feeling fairly safe with a barrier and a large security distance between us. I found the angle of view pretty funny and quickly realized that it was a good situation to try to do a second test of phantogram making. The camera first scared the feline, but it came back later and I had a second chance.
The result is pretty good. I aligned the views with hugin, by having horizontality constraints on some homologous points, plus three exact-matching constraints to define the ground plane at zero disparity. The optimization found that the cameras were not parallel by a few degrees and deduced a pitch of around 47°. Among all valid solutions, this was exactly the one I wanted, although I realized it only later when I analyzed why this image works far better than my previous test.
The computed projection matrix creates a trapezoidal shaped image with elongated parts, but this is exactly the projection needed for the phantogram. I cut my final image inside this trapeze. When we look at the result laying flat, with an angle of 45°, the kitten seems to sit on the screen/paper — exactly what is awaited in a phantogram.
-- 2020-11-05, LX15 manual sync