The face-api.js JavaScript module implements convolutional neural networks to solve for face detection and recognition of faces and face landmarks. The face-api.js leverages TensorFlow.js and is optimized for the desktop and mobile web.
Dr Mike Pound on the Viola/Jones algorithm, a face detection algorithm that does not use deep learning, but is so good that it’s still in use today.
The original Viola/Jones Paper: http://bit.ly/C_RapidObjectDetectPaper