Get your Calibration File
The ZED devices are depth cameras that use stereovision, employing two displaced cameras to capture different views of a scene. By analyzing these two images, the system can determine relative depth information.
The calibration file contains precise details about the positions of the right and left cameras, along with their optical characteristics. This file is essential for the depth estimation process and ensures its quality.
This file is generated during our manufacturing process and is automatically downloaded by the ZED SDK or any compatible application at the first access.
Calibration files are saved in specific locations and are named after the camera's serial number:
- On Windows: C:\ProgramData\Stereolabs\settings
- On Linux: /usr/local/zed/settings/
The calibration file is always available for manual download from this webpage.: calib.stereolabs.com
When using the ZED SDK, you can access parameters via getCameraInformation(). This function returns both the parameters from the raw file and those of the rectified images.
By default, a self-calibration process runs at each camera initialization to optimize parameters from the file. The returned parameters are the optimized ones that will be used by the SDK.
Calibration Parameters
The ZED calibration file contains intrinsic parameters for both the left and right sensors at each resolution. Here is an example:
[LEFT_CAM_2K]
fx=1952.5
fy=1952.5
cx=1104
cy=621
k1=0
k2=0
p1=0
p2=0
k3=0
- fx and fy are the focal length in pixels.
- cx and cy are the optical center coordinates in pixels.
- k1, k2, p1, p2, and k3 are distortion parameters.
These data match the pinhole camera model.
Stereo Parameters
The stereo parameters, also called extrinsic parameters, represent the relation between the left and right sensors. More precisely, the position of the right sensor from the left sensor with the center of rotation being the right sensor itself.
[STEREO]
Baseline=120
TY=0
TZ=0
CV_2K=0.0160464
CV_FHD=0.0160464
CV_HD=0.0160464
CV_VGA=0.0160464
RX_2K=0.0111974
RX_FHD=0.0111974
RX_HD=0.0111974
RX_VGA=0.0111974
RZ_2K=0.000456281
RZ_FHD=0.000456281
RZ_HD=0.000456281
RZ_VGA=0.000456281
- Baseline is the distance between the optics in mm.
- CV_*** also called RY_*** measures the optical convergence.
- RX_*** and RZ_*** are the other rotation axes describing the transformation between both sensors. Rotations are represented in the Rodrigues notation.