OpenCV face detector FP16 weights 31fc22bfdd907567a04bb45b7cfad29966caddc1 https://raw.githubusercontent.com/opencv/opencv_3rdparty/dnn_samples_face_detector_20180205_fp16/res10_300x300_ssd_iter_140000_fp16.caffemodel OpenCV face detector UINT8 weights 4f2fdf6f231d759d7bbdb94353c5a68690f3d2ae https://raw.githubusercontent.com/opencv/opencv_3rdparty/dnn_samples_face_detector_20180220_uint8/opencv_face_detector_uint8.pb