When a 752x480 image sensor is used for an ANPR camera, the following takes place:

A) To cover 4 meters of the road, the resolution of the license plate image will be: 752pixel / 400cm = 1,88 pixel/cm. With this resolution it will not be possible to reach a decent license plate recognition rate (OCR software providers suggest to use a minimum resolution of 3 pix/cm to achieve 95% recognition rates).

B) To achieve a 3 pix/cm resolution with an image sensor of 752x480 pixels, the lane width that is covered is: 752pix / 3pix/cm = 250 cm. Therefore, only the central part of the lane will be covered with the target resolution of 3 pix/cm.

C) License plate detection and recognition can underperform when a 752x480 image sensor is used: issues with the installation of the camera (out of focus, dust in the lens, et.), and also sensitivity to  harsh meteorological conditions (rain, snow, fog, etc.) can affect the quality of the image and the performance of the ANPR system.

Imagsa’s Atalaya ANPR cameras use sensors of 2048x1024 pixels resolution. Hence, one Atalaya camera fully covers 7,5 meters of road width. With one Atalaya ANPR camera, one installation and one investment is possible to simultaneously detect multiple vehicles on 2 Lanes of traffic.

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