Let's talk about face alignment

Hi guys,

In Bob we have a 10 years old standard for face-alignment; in short we geometrically normalize the face using a set of affine transformations using the eyes as reference.

Some packages (like the face zoo and the deep-insight) does a very similar job, but with an automatic landmark detector on front. As far as I could see, they have a code to find the best affine transformation to match the automatically detected landmarks to 25 reference points of the face.

https://github.com/JDAI-CV/FaceX-Zoo/blob/5b63794ba7649fe78a29d2ce0d0216c7773f6174/face_sdk/core/image_cropper/arcface_cropper/FaceRecImageCropper.py#L101

Any thoughts on that?

Shall we put this in place?

I think this analysis of alignment makes at least a small report (if not a conference paper).

ping @mguenther @amohammadi @ageorge