Camera Calibration

Overview #

Camera parameters such as focal length, field of view or stereo calibration can be retrieved for each eye and resolution:

  • Focal length: fx, fy.
  • Principal points: cx, cy.
  • Lens distortion: k1, k2, k3, p1, p2.
  • Horizontal, vertical and diagonal field of view.
  • Stereo calibration: rotation and translation between left and right eye.

Using the API #

Camera parameters are available in CalibrationParameters. They can be retrieved using getCameraInformation().

CalibrationParameters calibration_params = zed.getCameraInformation().camera_configuration.calibration_parameters;
// Focal length of the left eye in pixels
float focal_left_x = calibration_params.left_cam.fx;
// First radial distortion coefficient
float k1 = calibration_params.left_cam.disto[0];
// Translation between left and right eye on z-axis
float tz = calibration_params.T.z;
// Horizontal field of view of the left eye in degrees
float h_fov = calibration_params.left_cam.h_fov;

calibration_params = zed.get_camera_information().camera_configuration.calibration_parameters
# Focal length of the left eye in pixels
focal_left_x = calibration_params.left_cam.fx
# First radial distortion coefficient
k1 = calibration_params.left_cam.disto[0]
# Translation between left and right eye on z-axis
tz = calibration_params.T.z
# Horizontal field of view of the left eye in degrees
h_fov = calibration_params.left_cam.h_fov

CalibrationParameters calibration_params = zed.getCameraInformation().cameraConfiguration.calibrationParameters;
// Focal length of the left eye in pixels
float focal_left_x = calibration_params.leftCam.fx;
// First radial distortion coefficient
float k1 = calibration_params.leftCam.disto[0];
// Translation between left and right eye on z-axis
float tz = calibration_params.Trans.z;
// Horizontal field of view of the left eye in degrees
float h_fov = calibration_params.leftCam.hFOV;

Note: If self-calibration is enabled, calibration parameters can be re-estimated and refined by the ZED SDK at startup. Updated parameters will be available in CalibrationParameters.

Calibration Tool #

It is possible to recalibrate your camera manually using the ZED Calibration tool. However, we do not recommend this for ZED 2 cameras. They go through extensive and rigorous multi-step factory calibration (including thermal measurements), and a manual calibration might degrade its calibration parameters.