[Shotwell] Enhance face detection

[Narendra Acharya <narendra_m_a yahoo com>]

Hi,

I was looking at the current face detection code in shotwell 0.29.2 and feel that it can be enhanced.

So I pulled the code from https://gitlab.gnome.org/GNOME/shotwell.git and started making some changes.

1. Do not run another process for face detection (shotwell-facedetect) but integrate the OpenCV calls into shotwell and link to OpenCV libraries

2. Ability to use OpenCL when available on the platform using T-API in OpenCV 3.x

3. Eventually add face recognition on photos using a trained model based on faces labelled by the user - this would need a few faces to be tagged by the user before the OpenCV face recognition calls can be used (https://docs.opencv.org/2.4/modules/contrib/doc/facerec/facerec_tutorial.html).

Is there anyone else working on this area? 

Thanks,

Narendra