Night time license plate recognition

[joec999 0]

Hi,

 

I'm new to the forum and have installed many indoor CCTV systems over the years. Recently, I was presented with a new challenge - outdoor license plate capture at a gas station.

 

I installed an Everfocus EQ550T day/night camera with a fujinon 5-50mm day/night varifocal, DC auto iris lens. The recorder is an Everfocus EDR-1620 DVR set up to record at 720x480 and record quality for the camera is set to superior.

 

The pumps are about 70 feet from the camera and the lens is zoomed all the way out. Daytime performance is good, and plates can be read if vehicles are at a standstill.

 

My problem is two-fold...

 

First is the field of view. For the amount of zoom required to get a decent plate capture, the field of view is only good for vehicles that pull up with the nose of the vehicle pointed away from the camera (due to the position of the vehicle relative to the pump), I thought that perhaps I could capture the vehicles as they pulled up when coming from the opposite direction but I found the capture not always to be clear and reliable. The camera won't allow me to set a manual shutter speed with an auto iris lens attached and stays fixed at 1/60 sec.

 

Would installing a manual iris lens and using electronic shutter control improve the capture in this situation? I haven't tried this and would like to get some input.

 

Second issue - night time performance. The pumps are overhead lit under a canopy and I find that vehicles with plates positioned close to the ground are shadowed by the overhead lights to the point that they are difficult to read. I suppose part of the issue may have to do with MPEG4 compression of the recorder as they appear more blocky or pixelated in low light areas of a scene when played back. I've turned on backlight compensation and disabled DNR and readability seems to be better but still not completely reliable.

 

The camera has a IR cut removal feature and I've been considering fitting a manual iris, 50mm lens with an IR pass filter to block out visible light and illuminate the vehicles license plate area with a IR illuminator for night time capture, and also using electronic shutter control to get better moving vehicle capture.

 

So, after all this brain scheming doe's anyone think that any of the above ideas would actually work or do I cave and start looking for a license plate capture camera? If I have to consider a plate capture camera, can someone tell me if they are effective at capturing moving vehicles in the overhead lighting conditions mentioned earlier?

 

Any input appreciated,

 

Joe

[megapixel man 0]

Joe,

 

Your idea for the first part of your problem may help, increasing the shutter speed will help, a manual iris lens may assit further. Going to a good day/night megapxiel camera will assit even further. To read plates or any text it's all about the pixels on target.

 

For night time, yes blast out the IR, and keep a fast shutter speed. Then you could try a visable light cut filter if just adding the IR isnt enough.

 

See this: there is no light other than a good IR Illuminator. The plate looks flared out. There is no visable light cut filter. The car is moving.

 

 

Then if you've got the pixels on target right you can zoom into the live or recorded image and hey presto:

 

 

 

let me know if you need more info

[bpzle 0]

What camera is that? Arecont?

 

If you had to replace the camera used in the above picture, what would the cheapest camera/ lens combo that you'd consider? I'm assuming a box cam would be the way to go?

 

Only MP IP cams I've had experience with thus far are Acti and I really don't think the DN Acti cameras I've used would be capable of that but then again... maybe with enough tweaking and right FOV who knows. I havn't used their box cams. Only DN cams I've used are the 1231 and the 3011.

[joec999 0]

This is not a reply to anyone, but more about a product that I spotted awhile back - Messoa SCB265iHN5 INTELLIGENT LICENSE PLATE CAPTURE CAMERA 540TVL, ICR DAY/NIGHT, OSD.

 

The camera has traffic settings which I would assume gives it some kind of shutter priority. I spoke to Messoa and they didn't recommend it for night time use, but I wondered afterward if it could do the trick with a good IR source. I didn't bother calling Messoa back about this question as they were pretty adamant about steering me toward a higher end product. Has anyone had any experience with this product?

 

Just throwing this out there for thought.

 

Joe

[rory 0]

Look At Bosch/Extreme CCTV Licence Plate Cameras for 24/7 operation (Eg. Reg-L), they have been making them for years, and they work - big $$ though. However they also require proper placement.

 

 

 

http://products.boschsecurity.us/en/TAMS/products/bxp/CATM4ee759c007a61cbce559f31fd53d9314