[0x00000000]

Have you ever tried to read a license plate on dash cam footage? Unless they’re right in front of you in traffic it’s basically impossible. You would probably need a high resolution camera taking pictures every couple seconds instead or maybe when 8k dash cams are commonly available.

[mnw21cam]

Um, yeah, a couple of months ago I pulled my 4k dashcam footage for a car I was following reasonably closely, and I was shocked at how hard it was to make out the correct number plate. But that's largely because the camera is (rightly) extremely wide-angle.

Police cars with ANPR presumably have a camera with a slightly more zoomed-in view. I don't know.

[defrost]

> Police cars with ANPR presumably have a camera with a slightly more zoomed-in view.

Sixteen+ years ago when making demo plate recognition systems for mobile use, the "cameras" were good lenses onto industrial machine vision processing arrays.

Light sensor cells backed by neighbourhood array processing hardware that was uploaded with a series of filters -

anti jiggle filter to reduce vibration effects so that successive frames "stacked" correctly and the ROI (region of interest) didn't wobble,

Then a ROI search to best guess "back end" of vehicle and licence plate location

sharpness filters to enhance letter against plate contrast

letter + digit "trained" filters that were primed to do the best match

The output was dejiggled "smoothed" images (ie nearly raw made up of rolling average of a few successive frames == good clear slighly processed image) + "best match" image (previous smoothed image + sharpened + overlaid best guess letter shapes) + text output of guessed licence plate.

All that worked pretty well - that was my last contact with that specific job, I was doing a lot of speculative contract work for a machine vision specialist supplier at the time.