Hello

I assume there could be experts here about this topic.

As a cyclist, I'm tired of having to dodge cars/motorcycles parked on bike lanes, and was curious to know if there were any good open-source projects to analyze a video stream, and detect license plate numbers.

Google returned a single project called OpenALPR based on OpenCV.

Generally speaking, is pattern recognition so complex that authorities rely on expensive, closed-source solutions?

Thank you.

Gotta be, they use high speed cameras to check license plates on parked cars by law enforcement.

My understanding is that the police cars have video, they process the license plates and if a number comes up for any form of reason, this alerts the patrol persons and they deal with it accordingly.

Whether or not any of that or some form is open source I do not know. I get the impression that it is somewhat real time though because what would be the sense of post analysis in that case?

I'd guess the first thing to do would be to obtain video of what you wish to have and see if that video is of high enough quality to provide the proof you wish to provide to authorities. Some issues there would be the guarantee of clarity, validation that any evidence has not been tampered with, and things of that nature. It also wouldn't matter if you had some video equipment which failed to catch enough of a scene to prove incorrect actions. Probably better to take a still photo of wide enough range and sufficient resolution/clarity to illustrate time and day and the offense. Considering you've mentioned the car was parked, and yes I get that it takes your time to stop and do this. Sometimes the visible scene that someone is documenting an offense may shame or scare offenders into no longer offending.

I think I'd discuss this with law enforcement first. Going through the effort to prove your point may be initially fulfilling and subsequently frustrating if nothing comes of it. For instance you need to make sure that they agree it is an offense and what the terms of proof require. It may be unacceptable for you to provide video or pictures, even if that makes perfect sense. They may not be able to defend a citation and it would then be costly for them to do so and lose based on unofficial information. The laws may be structured such that only the first person observation by an officer is sufficient as proof.

they use a similar system in parking wars but no mention of what software they use (they occasionally show their laptop screens).

Thansk for the infos.