Questions · Cameras
Why does my camera not read number plates if the image looks fine?
Because a general surveillance camera and a number plate camera do two different jobs with opposite settings. The surveillance one exposes so the whole scene can be seen; the number plate one exposes for the plate and leaves the rest almost black, with a very fast shutter to freeze the car and low gain so there is no noise over the characters.
On top of that, the number plate is retroreflective: it sends the light back where it came from. That is why dedicated cameras carry their own infrared illuminator mounted on the axis of the lens, and that is why at night they read the plate even when the car is in the dark. An ordinary camera with the headlights head-on, on the other hand, is blinded and gives back two white blobs where the plate was.
And there is the detail: you need a fair number of pixels across the width of the characters for an automatic reader to get it right. A camera that takes in the whole entrance lane and half the yard does not reach that, even if the image looks good to the eye. If number plates have to be read, one camera goes in for that and a different one for seeing the scene.
Where it is set out in full.
Where you can see it working.
On the IRIS Neural website, on real scenes.
All the questions.
Five hundred and forty-four, grouped by topic. Each with its own page.
Get started
See it working.
A written answer is enough to decide whether it interests you. To know whether it works at your site you have to see it on a real scene, with the image as it is and, on top of it, what the system understands from it. That is on the IRIS Neural website, which is the group's product.