LPR Walk Through / Tutorial

crc2004

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I documented (link below) one LPR solution that I came up with from reading multiple LPR posts here. While it's not comprehensive it does have the essentials to get someone started for the price of a camera ($180) and about 6 hours of configuration / setup. My solution picks up about 650 license plates a week but a few times when I needed a plate due to suspected criminal activity the plates had been removed and/or covered.

IPC-HFW5231E-Z12 LPR from 137 feet
My favorite plate:
Screen Shot 2018-02-14 at 10.00.26 PM.png

Typical night time plate:
Screen Shot 2018-02-14 at 9.51.21 PM.png
 
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jazzy1

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could you guys post some of your Night settings?? I'm using a SD49225T-HN

to test OpenALPR and am getting excellent results in the Day but having a tough time at night....can you please post your Exposure settings, etc??


Thanks!
 

catcamstar

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could you guys post some of your Night settings?? I'm using a SD49225T-HN

to test OpenALPR and am getting excellent results in the Day but having a tough time at night....can you please post your Exposure settings, etc??


Thanks!
I found these settings somewhere on this forum, which work great on my HFW something:

Shutter manual 1/2000
Gain 10-40
Iris 40
HLC 65
3dnr 45
Smart IR on

I can't see the cars anymore, but the license plates pop out very well.

Hope it helps you too!
CC
 

richardgohth

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I found these settings somewhere on this forum, which work great on my HFW something:

Shutter manual 1/2000
Gain 10-40
Iris 40
HLC 65
3dnr 45
Smart IR on

I can't see the cars anymore, but the license plates pop out very well.

Hope it helps you too!
CC
nice, sample pics?
what is your distance?
can try increasing iris, hlc, reducing gain and 3dnr
 

catcamstar

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nice, sample pics?
what is your distance?
can try increasing iris, hlc, reducing gain and 3dnr
Here's a slice from a screenshot from last night (left some letters for you as this is my private car):


This is shot from a HFW5231-Z5, no zoom, from 25-30meters (that's almost 98 feet according to Google) with the settings mentioned above. Cam is "high" up. No additional lightning (there is almost no ambient light on our driveway), however cars drive at max 5km/u due to slope, bumps + curves.

Play with the settings until you get a crisp & clear plate.

Good luck!
CC.
 

jetracer86

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Night time image captures are a pain in the butt to configure but achievable. I recently purchased two Hikvision DS-2CD4A26FWD-IZH and one Vivotek panoramic and lets just say I have consumed a lot of coffee to get these to work at night along a highway. I have found trial and error is the only way forward as each application is different.

My biggest regret during planning is that I did not take the advice of others in this forum and get the camera with a better zoom. My initial goal was to capture license plates (no ALPR) and once I recovered from the substantial project cost, repurpose these units elsewhere. I was a bit skeptical as well that I could capture a 55+ mph moving vehicle. I am still fine tuning my settings, but it can be done. Good luck! :)
 
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My biggest regret during planning is that I did not take the advice of others in this forum and get the camera with a better zoom.
After having installed my own LPR system, my advice to a newcomer would be to consider buying a couple of Dahua SD49225T-HN cameras. The price differential over a good bullet camera (e.g. the Z12E) is only about $100 per camera, but the extra zoom combined with the ability to adjust the angle and direction without physically moving the camera might make it worthwhile.
 

MachAF

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I found these settings somewhere on this forum, which work great on my HFW something:

Shutter manual 1/2000
Gain 10-40
Iris 40
HLC 65
3dnr 45
Smart IR on

I can't see the cars anymore, but the license plates pop out very well.

Hope it helps you too!
CC
Having issues with HFW5231E-Z12E. Those settings didn't work at all for me. I'm basically in pitch black area, no street lights on a gravel road. Of course auto focus is all jacked up ( don't understand how its that difficult for Dahua to fix)
 
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pozzello

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1/6 shutter will get you BLURRY plates for sure, unless cars are moving VERY slowly.
Most people end up ~1/1000th or shorter so as to minimize blur on moving plates.
the faster the cars are going, the shorter exposure you'll need...

camera megapixels is not so important, but you need 100 PPF or more to read plates, which is where the zoom comes in,
and PTZ certainly helps dial things in more easily. You also need different focus settings for night as IR refracts slightly differently than visible/white
light. Some lenses are better at compensating, but do so by splitting the difference so neither is perfect. Once you get the right
view and dial in the exposure to minimize blur, you may find you need more IR cuz it's just too dark.

I suspect MachAF just needs more IR...
 

MachAF

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1/6 shutter will get you BLURRY plates for sure, unless cars are moving VERY slowly.
Most people end up ~1/1000th or shorter so as to minimize blur on moving plates.
the faster the cars are going, the shorter exposure you'll need...

camera megapixels is not so important, but you need 100 PPF or more to read plates, which is where the zoom comes in,
and PTZ certainly helps dial things in more easily. You also need different focus settings for night as IR refracts slightly differently than visible/white
light. Some lenses are better at compensating, but do so by splitting the difference so neither is perfect. Once you get the right
view and dial in the exposure to minimize blur, you may find you need more IR cuz it's just too dark.

I suspect MachAF just needs more IR...
You're correct. Car was moving too slowly...Deleted the bad info. Back to the drawing board.
 

DLONG2

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Night settings for my HFW5231EZ5, (NOT the SD49225T-HN as earlier said):

Conditions/Picture:
Brightness: 50
Contrast: 85
Saturation: 50
Sharpness: 85
Gamma: 50​

Conditions/Exposure:
Anti-flicker: Outdoor
Mode: Manual
Stutter: 1/2000
Gain: 0 to 30
3D NR: Off
Grade: 50​

Conditions/Backlight:
HLC = 70​

Conditions/WB:
Auto​

Conditions/Day & Night:
B/W​

Conditions/IR Light:
SmartIR​
 
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0blar

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Hi
@kevkmartin

Since a long time, will it be possible to post your process_alpr.pl file ?

Thanks again
 

DLONG2

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Anyone with LPR interest, be sure to look over the free Windows program designed by @Gymratz. It allows for the automatic collection and viewing of plate data when subscribing to the $5 a month 'Watchman' plan at OpenALPR.com. Here's a link to the article posted by @tech101 on how to install the program:

 

wittaj

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You only need to ask in one thread. It will be seen.

But yes, except it has been replaced with the newer model 5241E-Z12E

 
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