Face morphing

In Chapter 1, Getting Started with Image Processing, we discussed a naive face morphing technique based on simple α-blending, which looks terrible if the faces to be morphed are not aligned.

 

Let's conclude the last chapter by discussing a sophisticated face morphing technique, namely Beier-Neely morphing, which visually looks way smoother and better than α-blending for non-aligned faces. Here is the algorithm:

1. Read in two image files, A and B.
2. Specify the correspondence between source image and destination image interactively (by computing facial key points with PyStasm) using a set of line segment pairs. Save the line segment pair to lines file.
3. Read the lines file. The lines file contains the line segment pairs S_i^A, S_i^B. 
4. Compute destination line segments by linearly interpolating between S_i^A and S_i^B by warp fraction. These line segments define the destination shape.
5. Warp image A to its destination shape, computing a new image A'. 
6. Warp picture B to its destination shape, computing...