I've played a bit with CLAHE and pre-processing the images with it before sending to the AI can definitely help. Unfortunately I've found little guidance on how to set its parameters with my googlefu.
Here is an ~10 second clip of that security camera footage I mentioned of an actual crime where the people paid to monitor the cameras totally missed it, the entire event lasted ~30 minutes, the thefts were discovered the next day.
CLAHE enhanced AI performance comparrison
Dual frame view "normally" processed by the MobileNet-SSD AI on the left. On the right is the result of images pre-processed with CLAHE before going to the AI sub-system. The images certainly look better to the naked eye, but I doubt it would have been enough to make a difference to the people who were obviously not paying attention.
If you want to play with this, I'll share my Python code, if requested. It reads from a video file or a "live" camera on /dev/video0 using OpenCV cv2.VideoCapture(). This code uses the Movidius NCS, so as far as I know it will not run on Windows. Analyzing the input file, twice per frame, gave me ~4.5 fps meaning the NCS was processing ~9 fps.
