Mastering OpenCV 3 - Second Edition

Triangulation

As the shape we are looking for might be distorted, such as an open mouth for instance, we are required to map our texture back to a mean shape and then apply PCA to this normalized texture. In order to do this, we will use triangulation. The concept is very simple: we will create triangles including our annotated points and then map from one triangle to another. OpenCV comes with a handy class called Subdiv2D, which deals with Delaunay Triangulation. You can just consider this a good triangulation that will avoid skinny triangles.

In mathematics and computational geometry, a Delaunay Triangulation for a set P of points in a plane is a triangulation DT(P) such that no point in P is inside the circumcircle of any triangle in ...