Dedicated License Plate Cam project

[DanPOE]

5MP is going to be 4:3 and not 16:9 AR FYI..

I get adequate reads @ 720p, with your optics and camera pixels wont all that important.. at least not enough to pay +$100 for a measly extra MP.. save that money for IR or CUDA HW.

that angle looks doable, nice thats a culdesac so you get em both ways with a single camera.. I think your going to want to use pre-warping to get accurate reads.

And the 4MP Dahua looks to have much lower Lux than the 5MP I've seen so far.

Glad you think the angle is ok. I could go from the other corner of the house to reduce the angle but that would add another 30ft and need probably a 125mm lense.

ALPR does the pre-warping?

Another option is for me to place a small bullet camera at the street and mailbox. But the entails running CAT under the sidewalk and digging etc. Easier to deal with the angle I tihnk.

 

[nayr]

see: https://github.com/openalpr/openalpr/wiki/Camera-Calibration

 

[DanPOE]

Since I'm in no rush.. I'm going give the $102 5MP camera a test. If it works out then it is a pretty good low-cost option for others.

http://www.aliexpress.com/item/5MP-..._6&btsid=fbb0cb47-f272-4b50-a671-dc6e0a7da6b3

 

[nayr]

That camera does not have auto-back focus, from what I can tell.. and that's proven to be a critical requirement for adjusting the focus from night/day as the IR Reflection from plates seems to change the focal point.

I have to change the focus and switch from color to b&w profile externally via API calls at sunrise/sunset

 

[pozzello]

Looks like DanPOE's gonna be at quite an angle to the street, as well as 200ft away...

edit: when will i learn to read the rest of thread before responding? sheesh...

 

[DanPOE]

That camera does not have auto-back focus, from what I can tell.. and that's proven to be a critical requirement for adjusting the focus from night/day as the IR Reflection from plates seems to change the focal point.

I have to change the focus and switch from color to b&w profile externally via API calls at sunrise/sunset

On the Dahua, what stat do I look at to see it has auto-back focus?

 

[nayr]

here's an example, this image was taken with the focus changed to daytime.. but I left my IR spotlight on, so you can see the plate is out of focus while the rest of the image is in perfect focus.. the next car that went by a few mins later, the IR spotlight was either off or no longer effective, so the plate was in perfect focus.

 

[nayr]

the Dahua has it listed as 'ABF' and if you look at a photo of the ass end, you can see a button for ABF that you can use durring install to help focus it in the field.. (its the button next to the yellow and green LED's)

 

[DanPOE]

the Dahua has it listed as 'ABF' and if you look at a photo of the ass end, you can see a button for ABF that you can use durring install to help focus it in the field.. (its the button next to the yellow and green LED's)

Excellent thanks. Sticking with a more well known brand seemed a wise choice as well. Dahua it is.

I also picked up an IR flood that is supposed to reach 300ft. I'll do some tests with it. I'll probably get a call because the police helo complains about it. LOL

 

[nayr]

I did a whole slew of research before buying that camera, thats the best candidate I found by far.. and yes I tend to favor Dahua but for this project I was willing to use anything cheap that worked.

I am already thinking of building a 2nd birdhouse cam to get em going the other way, but tha'll be a ways out.. if ever, needa bust some bastards with this camera first to help justify it.

Critical Features:

• Adjustable Focus or Back Focus
• Changeable Optics (CS Mount)
• MJPEG Stream Output at respectable FPS (15-20fps)
• BLC and/or HLC Modes
• Noise reduction
• Documented HTTP API, you'r going to need it.

Non Critical Features:

• Resolution, use better optics
• WDR
• 720p Substream in h264 for NVR use
• Smart Features/Motion detection

 

[DanPOE]

I did a whole slew of research before buying that camera, thats the best candidate I found by far.. and yes I tend to favor Dahua but for this project I was willing to use anything cheap that worked.

I am already thinking of building a 2nd birdhouse cam to get em going the other way, but tha'll be a ways out.. if ever, needa bust some bastards with this camera first to help justify it.

It definitely looks to be the right choice for the price.

I'm thinking I'll also get an enclosure with heat and fan for it.

 

[nayr]

edited that last post to have a list of what I've found both before and after purchase, if your comparing another camera run it through that list..

I dont think heat is nessicary at all, cold wont kill electronics (except batteries and liquid displays).. I see -30F from time to time and Ive never lost any cameras, regardless of low temp ratings.. nice thing about below freezing is there is no humidity to worry about, its better than room temp environment for electronics.. ever seen liquid gas cooling systems for overclocking?

now heat on the other hand, yeah make sure it can breath.. it generates enough heat on its own that all sealed off it gets pretty warm, when I put my IR cannon inside the birdhouse everything was too hot to touch in short order.. had to add a bunch of natural circulation and now its fine.. I can poke a finger through a vent hole and touch the IR cannon after hours of running and it is cool to the touch.. didnt need a fan at all, but it did need to be designed with thermal dynamics in mind.

 

[DanPOE]

edited that last post to have a list of what I've found both before and after purchase, if your comparing another camera run it through that list..

I dont think heat is nessicary at all, cold wont kill electronics (except batteries and liquid displays).. I see -30F from time to time and Ive never lost any cameras, regardless of low temp ratings.. nice thing about below freezing is there is no humidity to worry about, its better than room temp environment for electronics.. ever seen liquid gas cooling systems for overclocking?

now heat on the other hand, yeah make sure it can breath.. it generates enough heat on its own that all sealed off it gets pretty warm, when I put my IR cannon inside the birdhouse everything was too hot to touch in short order.. had to add a bunch of natural circulation and now its fine.. I can poke a finger through a vent hole and touch the IR cannon after hours of running and it is cool to the touch.

My main concern is moisture, but I think you're right that the heat from the camera will likely be enough to keep moisture out. I'll check out the prices.

 

[nayr]

with the IR cannon and camera on standard PoE I am just barely within my power envelope (15W), so keep that in mind.. if you have an enclosure that requires any additional power you might have to make different accommodations.

 

[DanPOE]

with the IR cannon and camera on standard PoE I am just barely within my power envelope (15W), so keep that in mind.. if you have an enclosure that requires any additional power you might have to make different accommodations.

My camera location gives me plenty of power options and I can easily have multiple POE runs if needed; or 120v if needed.

Any idea why lens would specify 1.3MP, 2MP, 3MP etc if what appears to be the important info is that they are made for 1/3 ccd's?

I'm thinking of a 10-120mm lens to give me more zoom if desired.

http://www.aliexpress.com/item/2-me..._6&btsid=356dbaac-52f3-452a-8824-e2bab7cc3433
or
http://www.aliexpress.com/item/Free..._6&btsid=1ba1af15-fbc7-4172-abc4-120887369f56
or
http://www.aliexpress.com/item/10-1..._6&btsid=356dbaac-52f3-452a-8824-e2bab7cc3433

 

[nayr]

if it meant anything it'd mean that the higher MP ones are higher quality optics.. without flaws that lower resolution cameras would not pick up on.

but it dont mean anything, as long as its bigger than your sensor size it'll work.. the camera does have an IR cut filter on it (I can clearly hear it click on my mic input) so I do not believe you even need IR corrected optics, for most of the night all your going to see is IR.. but if you have to run in B&W mode all day long I suppose it might be nessicary.. I have an IR corrected lens and I still have to adjust focus from day/night, I think plates + IR is a whole different focal point.. it seems to be like a hologram a few feet closer than it is.

I was trying to avoid too big of a lens, but that was ignorant of me.. the larger the aperture the better low light, but also the shorter the focal point.. and right now I am considering upgrading to bigger optics just to get a larger focal point, the extra zoom could be nice... so go with a 120mm if you think it may be called for.

 

[pozzello]

"I also picked up an IR flood that is supposed to reach 300ft".
those ratings are pure marketecture. what sort of thing is it?

i think you'd want more of a SPOT (well-focused) light to reach anywhere near that distance...

 

[DanPOE]

"I also picked up an IR flood that is supposed to reach 300ft".
those ratings are pure marketecture. what sort of thing is it?

i think you'd want more of a SPOT (well-focused) light to reach anywhere near that distance...

I got it for another area of the yard but I'll test it out since I already have it. I agree a spot would be better. This is the flood I already have: http://smile.amazon.com/CMVision-IR...&redirect=true&ref_=oh_aui_detailpage_o03_s00

I'm now thinking of following Nayr's example of a birdhouse; and this way I could actually have it fairly close to the road without a ton of work burying cable.



I've also ordered a GW camera to try out with XProtect http://smile.amazon.com/GW-Security...&redirect=true&ref_=oh_aui_detailpage_o09_s00

 

[pozzello]

why not here (forgive bad editing...)?



the setup could be made to look like a light pole of sorts if a birdhouse on the side of the road looks too odd...
you'd have a lot better angle and closer view on cars going in either/both directions. being closer to your targets
would make the rest a lot easier...

 

[nayr]

this is mine, adjusted for reality