8x fps speedup & servo output

[DavidMCampbell]

Hey! Cool project. I've extended it to do MJPEG streaming with target drawing etc. I've also added sub-image sampling so that inference is run repeatedly over slightly overlapping 300x300 images within the original image. This is so that targets are detected much farther away. It is actually faster too because scaling down takes so long, relatively.

Anyway, with 720p as an example, I discovered that you can get a 8x+ fps speedup just by using the CAP_V4L codec. Replace: cap = cv::VideoCapture(camera_device); with: cap = cv::VideoCapture(camera_device, CAP_V4L); 👍

Do you know how to get servo/PWM output working? There are some badass things that can be done if we can get the coral dev board to do servo/PWM output.