License Plate Capture Position and Recommendation

[dahomes555 0]

On Monday I installed an Everfocus EZ Plate Cam camera on the exit gate for an HOA. I have been out there twice to try to tweak the positioning and settings of the camera and the customer is only seeing about 1 in 5 license plates with enough clarity to tell what they say. I don't know if the camera itself is the problem or if I'm just not installing it correctly.

 

Here's the layout of what I'm working with:

 

 

The camera has a 9-22mm VF lens so I can definitely zoom in close enough, but part of the problem is that the exit lane I'm trying to cover is 20 feet wide and it's hard to zoom in close enough for the camera to do it's job. Cars could get to this exit from any of the three streets on the left, so it's very important to cover the entire 20 foot wide exit lane span.

 

Making things a little more complicated is that the camera location is about 500 feet away from the DVR location and is being transmitted with a VideoComm wireless transmitter, so simply adding another camera or two isn't really an option, since those things cost $850 ea!

 

Any recommendations you have would be greatly appreciated.

[ak357 0]

On Monday I installed an Everfocus EZ Plate Cam camera on the exit gate for an HOA. I have been out there twice to try to tweak the positioning and settings of the camera and the customer is only seeing about 1 in 5 license plates with enough clarity to tell what they say. I don't know if the camera itself is the problem or if I'm just not installing it correctly.

 

Here's the layout of what I'm working with:

[attachment=0]Screen Shot 2012-04-25 at 8.41.57 AM.jpg[/attachment]

 

The camera has a 9-22mm VF lens so I can definitely zoom in close enough, but part of the problem is that the exit lane I'm trying to cover is 20 feet wide and it's hard to zoom in close enough for the camera to do it's job. Cars could get to this exit from any of the three streets on the left, so it's very important to cover the entire 20 foot wide exit lane span.

 

Making things a little more complicated is that the camera location is about 500 feet away from the DVR location and is being transmitted with a VideoComm wireless transmitter, so simply adding another camera or two isn't really an option, since those things cost $850 ea!

 

Any recommendations you have would be greatly appreciated.

 

At the DVR end what is recording capture resolution ?

D1 ? CIF ?

 

Hmm, at given FOV of 20 feet

you are getting only Max 36 pix per foot (D1 recording)

kinda not a lot for Lic plate

Edited April 25, 2012 by Guest

[dahomes555 0]

D1

[MaxIcon 0]

What's the cause of the failure to read compared to the ones that you can read? Not enough resolution, motion blur, poor contrast? It it clearer when viewed live vs recorded?

[ssmith10pn 0]

You need a minimum of 45 to 50 pixels per foot.

[ronp 0]

I just installed a license plate cam in a similar situation. I went for 100 pixels/foot. With a 700TVL camera and D1 recording that's 1/7th of the image in width - and only the width of a car. With cars moving less than 30mph I can get several good pictures of the plates as they pass through the field. At 50 pixels/foot I think the plates would be barely readable and I agree with ssmith10pn that this would be the minimum resolution. If you have to cover three lanes you will proabably need two cameras.

 

My camera is a EN-V150K-70, 9-22mm (currently on ebay for $137).

 

I have not gotten it to work at night, however, and have some questions about the best settings for that which I'll put in another post.

 

-Ron

[jasper666 0]

Also using a EN-V150K-70 over here, working well during daytime using the auto shutter settings and ATR set to on.

The daytime settings don't work for nighttime though.

 

I did get some usable results at night setting the shutter to manual and 1/500 or 1/1000, though this doesn't even provide an image during the day. The automatic gain compensation whites out the screen and there's no way I can find to shut it off. Backlight and highlight compensation don't work on this camera when it is on manual shutter, which doesn't help matters.

 

Anybody have any better recommendations for night time license plate cameras?

[ronp 0]

I'm now having good luck with night captures. I have it set to 1/4000 and AGC set to 6 (the default). Bright day pictures are washed out but the plates are still readable. See below. Note that the picture of the Jeep in my previous post was with the shutter set to Auto. It makes for a better day picture but if I had to sacrifice (and apparaently I do for $150) I'd rather have a good night picture.

 

P.S. The manual I got with mine was a single page poorly translated POS. Here's a link to documentation for a camera that appears to have the same software: http://www.smarthome.com/manuals/76190.pdf. It helped me a great deal in understanding the settings.

[jasper666 0]

Thanks for the manual, I got mine off ebay from the same seller.. Same piece of paper.

 

I will try those settings at night tonight. If it works I may just spring for a 2nd one at that price, the daytime images I'm getting are very clear.

[ronp 0]

Besides 1/4000 and AGC=6 I have

 

White Balance/ATW/Environment=Outdoor

Backlighting = BLC (not HLC)

ATR=On

Day/Night = Auto

Delay CNT = 10 (default was 1!?)

Day->Night = 20

Night->Day = 30.

 

I'm going to experiment switching to B/W mode and maybe putting on an IR filter to improve the day-time images. I have other cameras that would get car color if needed.

 

Ron

[jasper666 0]

Yup, was curious about the other settings. Seems there's some fiddling that needs to be done, but these really do the job.

I ended up buying another one today, so I can optimize one for day and one for night, mounted right next to each other.

[jasper666 0]

Let me know what you finally come up with. This seems to be working for me, daytime pretty good too. Attached snapshots.

 

shutter 1/4000, AGC 6.0

contrast and sharpness both bumped up to 140 in the picture adjustment

everything else default

[thewireguys 3]

Just doing some testing for a project coming up. The first parked car on the right is about 150FT away. FOV is about 30FT and the camera is mounted about 15ft off the ground. The moving car is about 140FT away and it is moving about 20MPH. 5MP Avigilon JPEG2000 at 40mm with a small IR illuminator and Avigilon ACC VMS

 

 

 

Cropped view

 

 

Full image car is about 190FT away and parking

 

 

Cropped image.

 

Edited May 1, 2012 by Guest

[ronp 0]

Two cameras, one for day (Auto shutter) and one for night (1/4000 shutter), would be perfect though I suppose there might be a $300 single camera solution somewhere out there. But it does seem that for $150, with a little tweaking, these EN-V150K-70 do the job.

 

Couple of notes about the settings:

 

- The default Delay CNT on my camera was 1 (second). I upped that to 10 because I wanted to prevent potential oscillation between night and day mode due to car headlights.

 

- With the shutter fixed at 1/4000 I'm concered a bit about dawn and dusk when the LEDs haven't yet turned on but the camera is still in color mode. It's unclear in the manual if Day-Night and Night-Day settings control the LEDs or if they are controlled independently with the sensor on the front. I bumped mine up from the default just in case figuring switching to night mode in more light would be better, anyway. Maybe a piece of black tape over the light sensor... Eventually I want to try an IR cut filter ($20 on ebay), night mode, and permanently leaving on the LEDs.

 

- I'll play with the contrast and sharpness, too. Upping the contrast can be troublesome if set too high because it can make M's turn into H's, D's turn into O's, etc. There might be a happy medium, there, though.

 

thewireguys: Show off !! " title="Applause" />

[jasper666 0]

Ronf- Have you tried 1/10000 at night?

 

I cleared up daytime images significantly today by changing to

 

speed: 1/10000

mode: always B/W

white balance: Anti-CR

ATR - On

[ronp 0]

Let me know how the night images are at 1/10000 - especially at dusk/dawn before the LEDs come on. 1/10000 may not let enough light in but it's worth an experiment. Do you know if the LEDs are locked on in B/W mode during the day? The manual doesn't say. If you have a digital camera or probably a cell phone camera just point it at the the video camera and the LEDs will be glowing white if the're on.

 

It sounds like it's easier for you to experiment than me. My camera is just beyond wifi range so I don't have a way to see a screen to adjust the settings myself. It's a comedy show doing it over the phone...

 

FWIW I used my camera last night. Had univited guests to our dead-end. Called my police buddy, gave him the tag #, and he came up and rustled them out.

[jasper666 0]

Good to hear that's working..

Though better at select times, 1/10000 was a step down overall. Not so good at dusk, or the brightest hours of the day. Slightly less clarity at night.

The IR lights did not come on when set to night only mode until it got dark, so these must behave independently.

I do like the b/w mode better though, it seems a bit sharper.

Moving back to 1/4000 for now with White balance on anti-cr, and I have ATR contrast set to high.

I will compare tonight and tomorrow's video with setting the shutter to 1/2000 tomorrow night. But I have a feeling I'm going to be mounting that 2nd camera in that same location.

I do have wifi, but I've been lazy about adding the local network onto my phone's viewer. I am using an android to configure the camera, over the Internet. It's sluggish but I count how many clicks I need to get to the next menu option and am able to navigate without seeing immediate feedback.

[jasper666 0]

This is the best I can seem to get from one camera. For about 20 minutes during dusk and sunset it's too dark, but I'll take the 23.5 hours..

 

shutter - speed 1/10000 agc 6.00

white bal - anti cr

night/day - auto

pict adj - bright 0, contr 122, sharp 129, hue 128, gain 123

atr - on luminance mid, contrast midhigh

[jasper666 0]

Different times with those settings. Deep night always crystal clear so leaving that out.

[rkninc 0]

Different times with those settings. Deep night always crystal clear so leaving that out.

 

 

You have a pic of how the camera is mounted and where?

[jasper666 0]

No I don't. It's mounted on a tree trunk, a few feet from the side of the road and about 15 feet off the ground.

[ronp 0]

For about 20 minutes during dusk and sunset it's too dark, but I'll take the 23.5 hours..

 

Maybe try putting a small piece of black tape over the light sensor. That should make the IR LEDs come on with more ambient light (dusk/dawn). You may also need to play with the Day-->Night and Night-->Day values to have the camera switch to B/W mode with more light or set it to only B/W mode (I think you did that at one point). Too bad the IR LED's aren't controllable through the menu or tied to the D/N, N/D setting.

 

So you've settled on 1/10000 vs 1/4000? Your high contrast setting must be helping to make that work. I'll give it a try, too.

Edited May 3, 2012 by Guest

[ronp 0]

You have a pic of how the camera is mounted and where?

 

Here's mine. A neighbor had a weathered 2x6 laying in his back yard that I used to box it in. Perfect match to the existing railing. I also had to carve a "notch" in the bush. The camera is zoomed 100% (22mm) and focused to about 30' from the camera so I get the whole back end of the cars and about 100pixels for the plates. I do get a fair number of dog noses and tails, too.

Edited May 3, 2012 by Guest

[rkninc 0]

 

Very nice.

[jasper666 0]

yeah, it's good enough. My 2nd camera arrived today. Interestingly, that seller bumped the price up from $137 to $299.