Camera Calibration
Overview
The calibration process is designed to remove lens barrel distortion and scale the image capture. In the case of PrintShot and HideShot, it also locates the image relative to the machine using the 4 ArUco markers on the Calibration Mat.
This process uses a special Calibration Mat configured to match the width of your table. It is provided with the system. The calibration process will map all of the circles into their correct position in the calibrated image.
Setup
Before starting the calibration process:
- Make sure the cutting machine is on and a connection has been established in PatternSmith.
- Roll out the calibration mat. Turn on the vacuum to make it as smooth as possible. If the edges are curling, they will need to be taped down.
- Make sure the mat is oriented correctly. The crosshair on the ArUco marker needs to be on the left when standing at the operator’s side of the machine.
Calibration
Calibration Mat Information
From PatternSmith, go to File > Preferences > Hardware > Vision System. Click on Calibrate. This window will appear:
Verify the number of circles in the rows and columns and enter those numbers in the appropriate fields.
Measure the Calibration Mat width and height as shown in the example. Be as accurate as possible. The more accurate the measurement, the more accurate the calibration. Enter the values in the appropriate fields.
Rotated Camera
If you rotated your camera 90° check the Calibrate a Vision System With a Rotated Camera button. The Next button will continue onto the Image Calibration window. However, the image will be rotated 90°.
Multiple Devices
If there are multiple devices, you will need to calibrate each camera. Check the Multiple Devices Need to be Calibrated Together button. The Next button will bring up the discovery window. Choose all the cameras that need calibration. Click Next and the following window will appear.
You can drag the images to put them in the correct order. You can also toggle them to be Horizontally or Vertically stacked.
Has Location Markers
**ONLY FOR CADSHOT USERS**
If you are start the calibration process from CadShot, a checkbox will appear above the preview of the mat. If your mat has location markers, check the Calibration Mat Has Location Markers checkbox.
Image Calibration
Make sure to move the cutting head out of the field of view of the camera after this step. Click on Next.
A picture of the Calibration Mat will be taken. Make sure all of the circles can be seen (the image can be scrolled up and down). If not, move the Calibration Mat until all of the circles can be seen and they are square with the camera. If the mat was moved, click Retake Picture.
You may also need to adjust the exposure using the Take Darker Picture or Take Lighter Picture buttons. Make sure the circles all look the same.
If there is more glare in one area, try turning off the lights to remove the glare.
If calibration fails, you will be directed back to this window where you can adjust the exposure as needed. You may also see a screen with yellow marks noting the circles that were found. This will help you determine how to adjust the exposure of the image.
Once the image is satisfactory, click Next.
Aruco Marker Locations
You will now need to jog the machine using the joystick to the center of the crosshairs next to each of the four Aruco markers and click Set From Plotter to record their X and Y values. If the X and Y values don’t update, you may not be connected to your cutting machine in PatternSmith. After all four locations are recorded, click Next.
Calibration Completion
It may take a few minutes. A notification will pop up if the calibration was successful or not. Click Finish when you see this message.
If you are calibrating multiple devices, the process will repeat. Move the Calibration Mat under the next device and repeat.
Calibration Failure Troubleshooting
Most failed calibrations are due to poor lighting, hot spots in the picture, incorrect measurements, incorrect data entry, or not all circles being visible. If there are continuing problems with calibration, contact Autometrix Support.