app: improved fix to commit 036ccc70.
After discussion with Sébastien Fourey and David Tschumperlé, it was decided that a better fix for the edge case raised in #2785 was to add a keypoint anyway, even if the point and none of its neigbours have a positive smoothed curvature, yet they have a positive raw curvature. In such case, we use the local maximum raw curvature instead of the local maximum smoothed curvature. (cherry picked from commit aa042586)
Showing with 30 additions and 10 deletions