This sample project shows how to implement own face tracking app from google sample apps.  Base of the project is from Google Mobile Vision sample apps.  The original sample source code could be found at https://github.com/googlesamples/android-vision.
This demo project have few my own implementation addition to original source codes.

• Take camera preview images using TextureView class on the CameraSourcePreview class.
• Save the camera preview images overlaid with face detection details.
• Switch the front and back facing camera option.
• Change the face detection detail overlay options.