I'm trying to train a dog face detector with dlib's hog pyramid detector. I used Columbia dogs dataset: ftp://ftp.umiacs.umd.edu/pub/kanazawa/CU_Dogs.zip
At first I would get a recall of 0%, but by increasing C value I managed to increase it to 65% on training set and 45% on testing set. After certain point increasing C value stopped helping (1000+) and would only slow down training.
Could you give any advice on how I could improve recall to a descent recall quality?