I wonder what the dnn module is doing internally? If the first layer is expecting 300x300 and you send it more does it crop? resize? analyze multiple overlapped 300x300 "tiles"? (which it seems should slow it down a lot). If you send it less, does it interpolate or zero pad? I'm going to see if searching comes up with some info on what is going on internally. I'm kind of surprised it doesn't give errors if the size is not 300x300 or whatever it was trained on. I'm pretty sure the NCS version chokes if the input is not 300x300, although if I recall the NCS SDK v2 api would do an automatic resize if necessary (I didn't pursue it as I only saw different, not better)
I've got some mp4 files (from a real crime at an industrial site) that are particularly hard to detect, I do get some detections but most of the time that the perp is in the frame its not detected. I plan to add the CLAHE to the pre-processing to see if it helps.
Doh! my object oriented stupidity, I searched on Timer not the tmrs objects created.