To use in an image:
$ python detect_faces.py --image group.jpg --prototxt deploy.prototxt.txt --model \
res10_300x300_ssd_iter_140000.caffemodel
To use in webcam:
$ python detect_faces_video.py --prototxt deploy.prototxt.txt --model \
res10_300x300_ssd_iter_140000.caffemodel