LPR is currently looking like about a 50% success, slow cars capture, fast cars don't

F

frankred

Getting the hang of it
May 14, 2015
302
16
So I got this Dahua IPC-HF5421E mounted this weekend. There are cars in this clip at 00:07 (pass!), 00:25 (pass), 01:25 (fail!), and 01:40(fail).

I turned the resolution down from 2688x1520 @20fps so that I could get to 25fps @ 2304x1296. I am waiting for more captures. I have a
super IR cannon thanks to @pozzello and @nayr .



See attached for settings and the lens.

settings.PNGLPR lens.jpg
 
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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

more fails as of now. I am hopeful for either settings or hardware pieces to get this working.



 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

whats your shutter speed? I run 1/1000 in day and 1/500 at night..

here are my night settings
 

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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

I remembered you had said 500 and 1000 before but I didn't find those settings until you posted that pic that included the Manual Exposure setting. Thanks so much. I start with you settings as a baseline. It seems there isn't too much traffic this late...
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

can you zoom in any more?

the day shot looks like it could be focused better.

the night shots, cranking down the exposure will help a lot.

also, you don't need 25fps. 10-15 will do, and setting your iframe interval to 10 or less will help with clarity.
each iframe is a complete image, and the ones in between are just diffs from the previous (or next) iframe,
so you get more consistant images with a lower iframe interval, even if you don't lower the frame rate...
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

are you using IR? it dont look like it

FPS has no effect on clarity, its all down to shutter speed but if you get 1 frame of the plate your good... fps just makes the video appear smoother as they drive by.. I run a high fps, keep it high as you can openalprd will adapt.

setting iframe to minimum it will let you is good incase it artifacts it will recover quicker, but if your wanting to use OpenALPR and are using MJPEG then there is no iframe to worry about.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

Thanks guys. I will adjust the iframe to as low as possible. There is no openalpr, it is connected to a 5 year old version of Milestone Enterprise (which should accept 3rd party apps). I am hoping to get that working on W10 this morning.

I would expect that the focus isn't spot on yet. I was erroneously testing focus with my car parked, and the lights off. As soon as the tag lights came on, I got a better image. It was 11:30pm though, so it was time to quit. I will work on the focus a bit this morning.
I am using IR like you have nayr, it made quite the difference on my parked car's license plate.

I had counted 40 paces that night to just short of that mailbox. I just checked and 10 paces was 21ft. So this is at about 85ft and 8ft up on a pole.
 
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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

Getting it all focused is tricky, I had to come up with completely different focus settings for day/night.. it depends on how large your focal point is and if you can manage to get both to overlap or not.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

Since this camera is so far away from me, I haven't been able to get down to try reducing the exposure on the manual lens since I last posted here 2 weeks ago. Using a starting point of @nayr settings, daytime looks good, but the plates are dim at night.
I am thinking that I need to have an AutoIris lens in hand next time I am there (hopefully next weekend) so that I have a fall back. That or a different camera.
AutoIris lenses are not something I know how to shop for. The current lens is 5.0-50MM, 1/3 1:1.4 pic

What do you guys suggest? I am looking forward to getting this solved!
 
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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

whats your gain set to? crank that up.. i am pretty sure my iris stays wide open almost always, espically at night.. dont think auto iris will do much.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

It was on 0-30. I tried it on 50-70 last night and I was getting glowing white plates. I was having bad luck with not much traffic for testing.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

try 0-50, it does better on its own adjusting.. I think thats what mine's at.. if you try to lock down the autogain with plates you'll miss dirty ones or get overexpoed on brand new ones, there's too much variation.. you alway want as little gain as possible, gain = noise and that effects the sharpness of the letters dramatically.

go get an old license plate and an orange construction cone, then at night go set it in the street at your target points... or go park your car in the middle of the street if there isint any traffic at all really, worse case you run out and apologize for double parking at midnight.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

Thanks. I'll try 0-50 tonight.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

I tried 0-50 and captured this Jeep at 21:01

Then I tried 0-60 and captured this car at 21:12 (zoomed)

Now I am waiting for a capture at 0-45.

Car in daylight also shown (slightly past best focal point).

lpr day.PNGlpr night gain 0-50.PNGlpr night gain 0-60.PNG
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

lpr night gain 0-45.PNG
0-45 got this, going down to 0-40

edit: here is 0-40 on a front plate.

lpr night gain 0-40 front plate.PNG

The more info the better right? Here is 0-32

lpr night gain 0-33.PNG

0-28

lpr night gain 0-28.PNG
 
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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

you need to zoom it more in it appears.. and you have to completely refocus it for night time or leave it in B&W always.. use the built in focus feature to fine tune
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

I was thinking the focus looked off too. It does look better in the daytime. Auto focus is failing without a target there. After hitting Autofocus, it went from around 200 to 500. Then a car drive by and looked like a marshmellow. I restored it.

Without being able to spend an hour a night for a few days, making manual changes onsite each time, I am worried that I am not going to be able to get this camera to work with the 4 hour drive. Is there a super camera that allows for all of this to be done via PC?
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

I restored the focus to defaults and it went to 180. I tried 200 and got a little better image. The same car circled the block and I got it at 220.

200
lpr night gain 0-35 focus 200.PNG

220
lpr night gain 0-35 focus 220.PNG

This one is either 220 or 240. Not sure due to timing.
lpr night gain 0-35 focus 2X0.PNG

This one was definitely autofocus: 240. It isn't as good as the last one. This was the least bad frame in the bunch.

lpr night gain 0-35 focus 240 front plate.PNG

Autofocus 240 on a rear plate. Switching back to 220 for the next plate.

lpr night gain 0-35 focus 240.PNG

220
lpr night gain 0-35 focus 220 number2.PNG
 
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Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

if you dont use a target plate to adjust focus its never going to work.. your going to spend forever fucking arround hoping you maybe got it better.
 
Re: LPR is currently looking like about a 50% success, slow cars capture, fast cars d

So I had a target plate for about 30 seconds today. I noticed a truck parked in view with his flashers on during daylight. I noticed the image was out of focus and I changed the focus down to 165 and it looked pretty good. So, I think you are right about the focus changing between day and night (well, I got to see it for myself :) ). It is too bad that setting doesn't follow the day/night profile.
 
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