The ARDev Calibration utility

The calibration utility included with ardev is based on the tsai calibration algorithm. The calib application can be used in two modes, either specifying the calibration points manually or have the utility detect them.

Manual Point Entry

For manual calibration you capture an image from the camera yourself and then create two point files. The first contains the 3D locations of 27 calibration points and the second file contains the pixel coordinates of the same 27 points (in the same order).

Once you have the three files (The image, the 2D points and the 3D points) you can then load them into the calibration utility.

First load the image, this is strictly speacking not required but is useful as a sanity check. File->Open Image

Then load the 3D points File->Load 3D Points

Then load the 2D points File->Load 2D Points

You should now be able to check the 2D points are at the locations you expected, they will be divided into three sets because the automatic method uses three faces of a cube, but this is not really important here.

Now proceed to the calibration section

Automatic Point Acquisition

If you are using the magic calibartion cube in the UoA robotics lab, or have a similar large cube with white dots on it (add a picture of the cube) then you will want to use the automatic method.

The Automatic detection method grabs an image from a Player server, so you will need to run one on the computer which has the camera attached. (player ~/PlayerConfig/1394.cfg on gin if you are at the UoA Robotics lab)

Once this is running fire up the calibration utility. Enter the server address in the lower left box and the camera index (probably 0) in the box next to it. Then click acquire, once you have a good shot of the calibration cube click acquire again and automatic processing will begin.

After its chugged away for a while the detected points will be displayed, confirm they seem correct then proceed to the next section.

If you dont get good points then use the Show stage button and stage spin box to get an idea of what went wrong.

Camera Calibration

After you have followed the steps for manual or automatic point acquisition all you should need to do is click calibrate. When the calibration is complete the 3D point set will be projected with the new camera model and the results displayed as black dots on the original image. Confirm these are accurate and then save your calibration.

Generated on Sat May 12 15:25:43 2007 for ardev by

1.5.1