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.GetCalibrationParameters();
// 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.