Question on ANPR camera

[MrM83]

Greetings. I am in the market to add an ANPR camera to my DS7716NI-I4.

I wonder if I can ask a few specific questions relevant to what I am hoping to achieve assuming I buy an 8-32mm varifocal lens camera (eg iDS-2CD7A46G0/P-IZHS) :

- can a camera be trained to read number plates in more than 1 location within the field of view?

- furthest reading point will be about 40 metres away, is getting a clean image at this distance realistic?

- there is no natural light to rely on, is this likely to be a problem?

- is a 4mp camera worth the outlay over a 2mp version?

Thanks very much for any advice.

 

[codlord]

It depends on what you mean by "location". The newest ANPR cameras I have are DS-2CD7A26G0/P-IZS (H3 firmware) and I think they do support 1-4 "lanes" of traffic. e.g. if pointing at a road with 2 lanes of traffic it can be configured to capture plates from both lanes. I have never used those features though so I can't comment on their ability or flexibility.

If your camera is a good distance away you want the "zoomiest" lens they do which as you say I think is the 8-32mm and you probably want to use the optical zoom to zoom in as much as possible to capture plates. e.g. you may have to sacrifice field-of-view for better plate reading. But you can experiment.

When you say no natural light do you mean it's indoors with lighting? All mine are outdoors so I can only say I can capture plates night and day with an exposure of 1/2000 but at night the camera recording view on the ANPR camera is total black so no good for general recording at night.

Hence why I generally have a non-ANPR camera in the same position as an ANPR camera - the ANPR camera for plates only, the normal camera for the field of view and general day/night recording.

Also, see this link hosted here which is a useful document from HikVision:

https://www.use-ip.co.uk/forum/attachments/7xxx-anpr-installation-configuration-guidance-pdf.5609/

 

[MrM83]

It depends on what you mean by "location". The newest ANPR cameras I have are DS-2CD7A26G0/P-IZS (H3 firmware) and I think they do support 1-4 "lanes" of traffic. e.g. if pointing at a road with 2 lanes of traffic it can be configured to capture plates from both lanes. I have never used those features though so I can't comment on their ability or flexibility.

If your camera is a good distance away you want the "zoomiest" lens they do which as you say I think is the 8-32mm and you probably want to use the optical zoom to zoom in as much as possible to capture plates. e.g. you may have to sacrifice field-of-view for better plate reading. But you can experiment.

When you say no natural light do you mean it's indoors with lighting? All mine are outdoors so I can only say I can capture plates night and day with an exposure of 1/2000 but at night the camera recording view on the ANPR camera is total black so no good for general recording at night.

Hence why I generally have a non-ANPR camera in the same position as an ANPR camera - the ANPR camera for plates only, the normal camera for the field of view and general day/night recording.

Also, see this link hosted here which is a useful document from HikVision:

https://www.use-ip.co.uk/forum/attachments/7xxx-anpr-installation-configuration-guidance-pdf.5609/

Thanks so much for your reply. To clarify a couple of points, I would like to be able to capture plates driving on (an accessible) private estate. The location of the camera will be on what is effectively a crossroads where each “road” off of it is approx 4m wide or so. The “lane” of most interest is the one in direct straight view of the camera and would be a bonus if I could capture plates of cars traveling perpendicular(ish) to the camera, as they turn through 90 degrees, to capture a plate when they are at 45 degrees, if that makes sense.

This would be at a different point in the FOV to the straight ahead lane, and maybe it wouldn’t work, not least due to level of zoom needed to capture the lane straight ahead. If the multiple “lanes” all need to be perfectly parallel to each other at the same distance, then this sadly won’t work for me to monitor multiple locations.

With regards to natural light, I meant there is no street lighting. It is an outdoor, rural lane.

Thanks again

 

[codlord]

Thanks so much for your reply. To clarify a couple of points, I would like to be able to capture plates driving on a(n accessible) private estate. The location of the camera will be on what is effectively a crossroads where each “road” off of it is approx 4m wide or so. The “lane” of most interest is the one in direct straight view of the camera and would be a bonus if I could capture plates of cars traveling perpendicular(ish) to the camera, as they turn through 90 degrees, to capture a plate when they are at 45 degrees, if that makes sense.

This would be at a different point in the FOV to the straight ahead lane, and maybe it wouldn’t work, not least due to level of zoom needed to capture the lane straight ahead. If the multiple “lanes” all need to be perfectly parallel to each other at the same distance, then this sadly won’t work for me to monitor multiple locations.

With regards to natural light, I meant there is no street lighting. It is an outdoor, rural lane.

Thanks again

The HikVision ANPR cameras will pick up plates at all sorts of angles although you probably get the best results with cameras straight ahead.

None of my ANPR cameras are looking at traffic straight ahead (there is just no mount point to allow for that) and some of my ANPR cameras are on bends/corners which of course means traffic naturally slows down which is a good thing for plate reading. They may not pick up 100% of plates and I do get some mis-reads and "NOPLATE" reads, as it can depend on vehicle speed, weather, light etc. But I would say they pick up a very high percent of vehicles going both ways on a bend or a road at almost any angle.

At night there are more factors affecting reading such as headlight dazzle, spider webs causing IR dazzle etc. All mine are rural location and I can still pick up "most" plates at night given the exposure setting I already stated above. Mine are mounted high enough to not get too dazzled by headlights and we have to regularly de-spiderweb etc.

 

[MrM83]

The HikVision ANPR cameras will pick up plates at all sorts of angles although you probably get the best results with cameras straight ahead.

None of my ANPR cameras are looking at traffic straight ahead (there is just no mount point to allow for that) and some of my ANPR cameras are on bends/corners which of course means traffic naturally slows down which is a good thing for plate reading. They may not pick up 100% of plates and I do get some mis-reads and "NOPLATE" reads, as it can depend on vehicle speed, weather, light etc. But I would say they pick up a very high percent of vehicles going both ways on a bend or a road at almost any angle.

At night there are more factors affecting reading such as headlight dazzle, spider webs causing IR dazzle etc. All mine are rural location and I can still pick up "most" plates at night given the exposure setting I already stated above. Mine are mounted high enough to not get too dazzled by headlights and we have to regularly de-spiderweb etc.

Thanks for the info that is really useful.

Just to clarify, as I’m still a little confused, is it possible to monitor different areas / direction of travel within the FOV?

 

[codlord]

Just to clarify, as I’m still a little confused, is it possible to monitor different areas / direction of travel within the FOV?

Yes.

To give an example, I have one ANPR camera setup monitoring a yard. In an ideal world the ANPR camera would be placed covering the single entrance/exit road but that was not possible. So I mounted the camera covering the whole yard. It's far from ideal of course as it's covering a large area and plates within the area can therefore be far away/small. So I get a lot of mis-reads/NOPLATE reads. But it does capture vehicles criss-crossing the yard at all sorts of angles/directions, when vehicles are turning around, going towards/away it does not really matter.

So if you have a cross-roads and mount the camera with a sensible zoom/field-of-view then the camera should capture plates going all angles/directions.

 

[MrM83]

Again, thanks very much!

 

[Phil]

As someone who had wrestled with prior technology, where you had to get as straight-on as possible AND restrict the field of view to one car's width in total to get the number plate large and clear enough to be read by earlier systems, I remember being amazed when I saw this quick demo video of the then newly arrived Hikvision ANPR cameras :0

A wide view, and cars at angles to the camera!!

Eight years ago tomorrow!