The Neven Vision face detector from Android
And some very messy code from about 10 years ago to call it and output the bounding boxes of the faces
./neven-face-detect file.jpg file2.jpg ...
Writes lines like
0 482x482+1004+400 1358,520 1358,520 1132,520 1132,520 1245,761 -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 file.jpg
with the bounding box and landmarks of the detected faces.