Each ZED and ZED Mini we ship is calibrated at the factory using special equipment to maximize the accuracy. However, you may recalibrate it yourself using our included ZED Calibration app. Most users will never have to do this, but it can be useful in the following situations:
- If your camera is very old and you want to take advantage of improvements in our calibration software
- If your camera has suffered a hard impact or other damage that may have caused parts to shift slightly
- To rule out (or in rare cases, verify) that a faulty factory calibration is responsible for inaccurate depth values
For more information about how the ZED's calibration works, see the What is the calibration file? article.
Using the ZED Calibration tool
The ZED Calibration tool comes with your SDK. You can find it in the following folders.
- Windows: C:\Program Files (x86)\ZED SDK\tools
- Linux: /usr/local/zed/tools
After launching it, you can select the Tutorial which will provide more visual instructions than this article. If you already followed the tutorial, press Start.
The calibration app works by having your ZED recognize patterns on your monitor. As such, it's best to turn off bright lights and close window blinds that may cause reflections on the screen.
Next, you'll see a grid with a red dot in the center. Aim your ZED at the monitor, and you'll see a blue dot where you're aiming. The goal is to get that blue dot to match the red dot. You'll have to do this several times as the dot moves to different positions.
Think of the dot as the light from a blue flashlight stuck to your ZED. The blue dot's size, shape and position depends on how you're holding it:
- Bring the ZED closer to make the dot smaller, and further away to make it larger
- Slide the ZED left, right, up or down without rotating it to the dot
- Tilt the ZED to slant the dot, making it more of an oval
In addition to the position of the dot, note the bars on the bottom and right sides of the window. They indicate the position of the ZED. The small gray dots on the bars must be inside the open spaces to complete each stage. This makes sure that you didn't position the dot in the right place by tilting it in the wrong direction.
When you have it positioned correctly, you'll see the red dot briefly turn into a rotating green timer. After 1 second, it'll automatically advance to the next stage.
As you go through the steps, you'll have to move the ZED further and further back, and eventually tilt it in each direction. This gives the tool a variety of reference points from which to calculate the calibration.
When finished, the tool will need time to create a calibration file using the info you provided it. Then, it'll save it to your computer in a folder that varies by operating system. Now, anytime you use that camera for any ZED application on that computer, it'll automatically use the calibration you just created.
Backing Up/Recovering Calibration Files
Calibrations are stored as files named with the camera's serial number, in a folder defined by your platform:
- On Windows: C:\ProgramData\Stereolabs\settings
- On Linux: /usr/local/zed/settings/
- On Windows (SDK <= 2.2.0): C:\Users\YOUR_USER_NAME\AppData\Roaming\Stereolabs\settings\
Changing the name of a file or removing it from that folder will prevent the ZED SDK from finding it. In this case, assuming you have a valid Internet connection, the SDK will automatically download your camera's original factory calibration file from the Stereolabs servers the next time you try to run an app built with the ZED SDK. You can also download the original factory calibration by visiting calib.stereolabs.com or from the setting panel of the ZED Explorer tool.