Automatic Calibration Requirements

This topic describes the requirements that must be fulfilled to obtain optimal calibration results.

Image Source Equipment Requirements

The image source equipment including: the camera, the lighting and the optical elements, must exhibit:

  • A linear response: The digital value of each color component must be proportional to the light intensity of the corresponding color.
  • A moderate color imbalance: The ratio between the response of the strongest color component and the weakest color component must be less than 5.

Calibration Target Requirements

The calibration target is a neutral color object located in the field of view of the camera during the calibration process.

The form of the target can be either:
  • Clustered light gray pixels located in a specific area of the camera field of view.
  • Non-clustered-light gray pixels located in a specific area of the camera field of view.
  • Non-clustered-light gray pixels located anywhere in the camera field of view.
The calibration target can be:
  • In the object to inspect.
  • A specific object placed in the camera field of view during the calibration phase.
The appearance of the target must be:
  • A neutral light gray color.
  • The level of the brightest component within 75% to 90% of the full scale.
  • The level of the darkest component above 15% of the full scale.

The target must contain at least 256 pixels satisfying the appearance requirements.

Acquisition Channel Settings

The parameter WBO_Mode must be set to ONCE.

The parameters defining the position and the size of the AWB_AREA must be configured such that:
  • It includes at least 256 pixels satisfying the calibration target appearance requirements.
  • It contains at least 1 line and 32 columns of pixels.
  • It is located entirely within the Camera Active Area.
Specifically on Grablink Base, Grablink DualBase, Grablink Full, and Grablink Full XR:
  • The LUT Operator must be disabled.
  • The position and the size of the cropping area must be configured such that it encompasses the AWB_AREA