| 摘要 |
<p>A vehicle video imaging system comprises a white-light LED array for illuminating reflective painted parts of a vehicle's license plate, a powerful flash with a visual spectrum cutout filter and a polarizing filter for illuminating any non-reflective license plate paint and the vehicle itself. A video camera with a polarizing filter turned 90 DEG relative to the one in front of the flash receives the illuminated image of the vehicle and its license plate. The reflective paint of a license plate will return polarized light as it is received, so the white-light LED array will provide all the illumination needed by the camera to get a good high-contrast picture of the license plate. The polarizing filters will combine to block out most of the light from the flash that was returned still-polarized by the reflective-paint license plate. All other surfaces that do not have reflective paint will bounce-back and scatter the light from both the polarized flash and white-light LED array. <IMAGE></p> |
