 Training data  The present model was trained on [the CMU Multi-PIE Face Database that is available commercially](https://www.cs.cmu.edu/afs/cs/project/PIE/MultiPie/Multi-Pie/Home.html). The input images were closely cropped to include the face of a person photographed at an angle between -90 and 90 degrees. The target frontal images were cropped and aligned so that the center of the person's left eye was at the same relative position in all of them. Having a precise alignment for the target images turned out to play a key role in the training of the model.  