After the previous 4 exercises, we can start to work on with the OpenCV face swap example in Processing. With the two images, we first compute the face landmark for each of them. We then prepare the Delaunay triangulation for the 2nd image. Based on the triangles in the 2nd image, we find corresponding vertices in the 1st image. For each triangle pair, we perform the warp affine transform from the 1st image to the 2nd image. It will create the face swap effect.
Note the skin tone discrepancy in the 3rd image for the face swap.
Full source code is now available at the GitHub repository ml20180820a.