Setting custom SharpV ALPR camera exposure levels for indoor installations - SharpV | SharpOS 13.6

AutoVu™ SharpV Deployment Guide 13.6
Product
SharpOS
SharpV
Content type
Guides > User guides
Version
13.6
Language
English
Last updated
2022-07-19

If the default exposure settings do not produce acceptable results, you can adjust the iris, shutter time, and gain settings of the SharpV ALPR camera to work best with your indoor installation.

Before you begin

  • Ensure that the lighting conditions match what is expected during normal camera operation.
  • Adjust the zoom and focus of the camera.

What you should know

  • In a correctly-exposed license plate image, the characters and the plate state are dark and well-defined, and the background is white or very bright.

    Under-exposed Correctly-exposed Over-exposed

    IMPORTANT: Modifying the exposure settings can greatly impact ALPR performance. You must test the system after modifying these settings.
  • In the ALPR image, it is normal that the surroundings of the plate are under-exposed while the plate itself is correctly-exposed. In the ALPR image, make sure that the plate is correctly exposed and ignore the quality of the surroundings.

Procedure

  1. Log on to the Sharp Portal.
  2. From the Configuration menu, select Cameras > Zoom and focus.
  3. From the Select your camera drop-down list, select the ALPR Camera.
    The live feed of the ALPR camera is displayed.
  4. Select the Show ruler check box.
  5. Place a stationary license plate in front of the camera so that the character height is 25 pixels.
    IMPORTANT: Do not modify the focus. The license plate might appear out of focus, but you are only adjusting the exposure in these steps.
  6. From the Configuration menu, select Cameras > Exposure.
  7. From the Select your camera drop-down list, select the ALPR camera.
    The live feed from the ALPR camera is displayed.
  8. From the Exposure drop-down list, select Fixed (indoor).
    Gain, Exposure time and Iris settings are displayed.
  9. Clear the Iris check box.
  10. Open the iris to 100% by moving the slider to the right.
  11. Set the Gain level to the minimum default value (0).
  12. Adjust the Exposure time to be as high as possible without resulting in an over-exposed image.
  13. If you reach the maximum Exposure time level and the plate image is still too dark, increase the Gain level and adjust the Exposure time until you are satisfied with the plate image.
    Tip: Increasing the gain level introduces noise in the image. Keep the gain as low as possible.
  14. When you are satisfied with the appearance of the plate images in the video feed window, click Save.
    The system displays the message: Configuration saved successfully.
Parent topic: About SharpV exposure adjustment for indoor installations