license plate recognition

[henke]

Hi,

Does anyone have experience on integrating ZM with some LPR software? Or if anyone has any links to get me going I will appreciate it very much.

Seems to be quite few GPL projects about plate recognition in general.

-h

[jameswilson]

this something i would love to see added. What we need is to get the algorithm used to recognise the plates. Do you know of any gpl projects that actually work?

[Ruler]

This would be an incredible add-on. I don't know of any that work, but that isn't to say that none exist that work. Even something that would sharpen the image from 640x480 to something readable; even if a car is close-up, you can't make out a whole heck of a lot. I heard about some method on the show Numbers (everything in it is based on real math, so I'm assuming it exists), but don't remember the name of it. It was highly CPU intensive, but pulled details out of photos that you never thought could be revealed.

Even an add-on that would sharpen an image and bring out details would be killer - I can read the plate number instead of having the computer do it as long as it's clear; I'm not *that* lazy...

[henke]

I dont know any actually working algorithms or projects, found some on sourceforge but did not yet figure out which projects were active and which not.

This feature will require lots from the image manipulation part and processing power. First the license plate has to be recognized and extracted from the rest of the picture and then the letters have to be recognised on the plate.

-h

[henke]

The feature would be used in connection with a database and compared to eg. allowed plates, and if some not allowed were found it would make an alarm.

[jameswilson]

Yes, and most of the time a special reg camera is required that is setup just to capture reg's and not the scene. Usually when we do it we use a reg cam and an overview cam

[subliminal_boy_9]

Hi,

Does anyone have experience on integrating ZM with some LPR software? Or if anyone has any links to get me going I will appreciate it very much.

Seems to be quite few GPL projects about plate recognition in general.

-h

While not what you're looking for directly, we have found a solution to this for our situation.

Our parking area has three exits. Two of them are high traffic, and these are where we concentrated our efforts. Basically we took generic B/W composite cams and put a good zoom lens on each. Then zoomed them as tight as they would go, and tested with parking cars in the exit to see if we could make readings on the plates. It's a bit of a low tech solution, but it works well.

Turns out we can make an accurate read, at least 60% of the time, that are able to be seen with the naked eye. That doesn't allow triggering of alarms and such based on plate ID, but it does allow us to ID a plate when necessary.

In addition, we get several frames as the car travels through the field of vision, so even if frame one doesn't have what we want, or the sun hits the car funny, or whatever, we still have 10-20 other stills that will give clues as to individual characters in the plate.

[jameswilson]

on this subject derwent make special anpr cams that have filters to allow high contrast plate recognition. They are designed to be fed into anpr systems but they do have video out that can be fed into zm, You wont be able to use them for anything else though as you basically get a plate and black everything else

[timfishy]

Yeah i had a look at some number plate recognition systems.

James was right when he said you cannot just use the scene camera. The systems have a scene camera so you can acutally see, which is just a normal colour camera. Then the ANPR cameras are usually specialised black and white cameras, they also use big infrared illuminators so its easy to pick out the digits.
From the article i read it was saying that they used higher definition cameras than normal. Also they were talking about shutter speed and how it should be as high as 1/10000 so you dont get blurred pictures.

The whole article was whether existing CCTV cameras could be used fo NPR. They concluded that most existing cameras in towns could not be used due to the fact that their placing was rubbish, lots of them couldnt get a high enough shutter speed, or were not good enough quality.


But then on the other hand, i doubt anybody with a ZM setup will be wathcing high speed cars...

Tim
Tim

[Ruler]

With the research that you guys have done into this, have you seen or do you know if a product exists that will import an image (JPEG), allow you to define the area where the plate is (I'm envisioning dragging a selection box), and process that area to bring out enough detail that one would be able to make out the plate number? Even capturing at 640x480 and parking a car right in front of the camera, I find it virtually impossible to make out the plate numbers.

Also, I believe that the majority of ZM users are like myself - the instances where we need to make out a plate number are minimal (a few times per year). Concentrating on building something like this into ZM would make more sense to me than having it automagically pick out the number of every plate that comes into a camera's view. This is just my opinion though; I could easily be mistaken.

[jameswilson]

what i think your getting at is imaghe enhancement and not anpr. Id like to know an easy to use app that can do this but as yet havbe failed to find one. As far as i understand about it its basically interpolation and anti-alaising. This can be done in most image editing apps. Once we know a way to do this well, i think i can incorporate this into zm4ms (i have always wanted to(basic enhancement not anpr) else id probably use gimp or something for he moment, but i dont really know how to use it lol

[Ruler]

I know that it's a separate issue than automatic license plate recognition, but it's close enough that I brought it up here. I don't know anything about image enhancement really, but have played with gimp/photoshop for hours and never really accomplished anything in this regard. (Sure, I can make it look like a stained glass window or like the image has been etched in stone, but that type of thing isn't all that useful. )

[jameswilson]

lmao i like that this window could you read any writing on the stained glass window lol.

I agree i know little about enhacement either. I have played with the two types above to allow zm4ms to scale images to suit without looking sh!te but thats all

[curtishall]

We sell a 'wide dynamic' camera from Topica. The camera has two purposes, the first to be used indoors pointing at windows or doors. The camera illiminates the white 'blooming' that other cameras have.

The second purpose is to pickup license plates. The camera uses the same technology to minimize the headlight glare so you can pickup images from the camera

http://www.bluecherry.net/store/product ... 101&page=1

PDF of some pictures:
http://www.bluecherry.net/product/tp2000wd.pdf