Serious Facial Recognition: Still Snaps?

[PeteCress 0]

At the consumer level, I am not seeing anything in the way of motion cams that allow recognition of a stranger.

 

Telling the something is going down: yes.

 

Telling what is going down: probably.

 

Identifying somebody that I already know: maybe.

 

But rendering an image of a stranger that could be used to

pick them out of a lineup? I don't see it.

 

- which begs the question: how about supplementing the video cam with some sort of still camera - analogous to a game cam?

 

I am currently running 5 cams at 1280x720. Four of them are capable of more, but performance suffers with the higher rez. At 1280x720, even in daylight I can only recognize people I know. Cams at ExtremeSurfCam.DynDNS.org.

Edited July 19, 2014 by Guest

[rayt 0]

if you more pixels to recognize people at distance

my 3mp cams capture faces at 10-20 ft away just fine, i can make them out most of the time

 

need to get myself a 5mp camera.

[Dirk_D 0]

I've been very impressed with Axxon Next,,,, a few issues, and I haven't played with it for a couple of months, but there's definitely promise with their system.

 

[myiicu 0]

What size lens are you using for facial recognition?

What is the target distance?

 

The cameras on your link look like general overview cameras with 4mm lens.

 

Facial recognition requires a dedicated camera with quality zoom lens.

 

With a proper sized quality zoom lens, facial recognition can be accomplished with just a 1MP camera.

 

 

If you want facial recognition with a general overview camera, than you will need a very high resolution camera.

 

Avigilon has 8, 12, and 16 MP cameras that are great for facial recognition in large areas such as stadiums, airports, and parking lots.

[buellwinkle 0]

You just need to get the face to be at least 85 pixels tall and you can do that with any resolution and people have been doing that for years with analog cameras. Having an overview camera to see the crime in progress is great, but you'll need close up cameras at choke points, or areas where the suspect has to traverse that are as narrow as possible and a camera either close enough or with a long enough lens to capture their face. I'm experimenting with 25mm lens in a Hikvision bullet and I bet I can ID someone 70'+ away, albeit with a 13 degree viewing angle.

[PeteCress 0]

The cameras on your link look like general overview cameras with 4mm lens.

 

Facial recognition requires a dedicated camera with quality zoom lens.

 

With a proper sized quality zoom lens, facial recognition can be accomplished with just a 1MP camera.

You nailed it. 4mm lenses.

 

You just need to get the face to be at least 85 pixels tall and you can do that with any resolution and people have been doing that for years with analog cameras. Having an overview camera to see the crime in progress is great, but you'll need close up cameras at choke points, or areas where the suspect has to traverse that are as narrow as possible and a camera either close enough or with a long enough lens to capture their face. I'm experimenting with 25mm lens in a Hikvision bullet and I bet I can ID someone 70'+ away, albeit with a 13 degree viewing angle.

Thanks myiicu and buellwinkle for the distinction between Overview and Closeup. That seems tb the root of the matter.

 

Is your 25mm a third-party add-on or did the cam come with it? I've got a spare DS-2CD2032-I and I'm thinking maybe I will swap out the 4mm for something longer once I determine placement/distance. Maybe two cams: one for the shop entrance (where the Beach-West cam is mounted already) and another for the gear lockers around the corner of the building (visible in the 4mm Beach-East cam).

 

I'm also guessing that if I resurrect my high-school trig, I will be able to compute the fields of view by solving for the third side of a triangle with two sides the same as the viewing distance and the known angle the same as the cam's focal length. Barring that, a protractor and some string.... -)

 

How about night vision? I am assuming that just the cam's IR is going to be futile and am lobbying for some supplemental full-time illumination at the site.

[myiicu 0]

Trig???

 

Lots of online lens calculators...

 

http://www.cctvlenscalculator.com/

 

http://www.theiatech.com/calculator.php

[buellwinkle 0]

I just took a 4mm ds-2cd2032-i, stuck a 25mm lens on, focused it on my boat, and i'm getting half the field of view that had with an 12mm camera there and everything is twice as big. Because it's such a long telephoto lens, the depth of field is not great, so I can get all the boats on my dock crystal clear which is what I want, but the boats in the distance are not as in-focus. I figure there's about a 100' depth of field.

[myiicu 0]

Back in the early 80's, trig. was a breeze with the HP-11C.

RPN (Reverse Polish Notation) ruled...