User manual

Small Vision System User Manual 40
c) Computes the rectification matrices from the joint calibration in (b).
7. When the calibration is finished, the parameter listing at the bottom is updated, and you have a
couple additional options in the lower button bar: save writes the parameter file to disk and OK
exits the calibration dialog and transfers the new parameters to the main smallv window.
4.1.2 Imager Characteristics
The calibration process must be related to the geometry of the camera imagers. There are three
important parameters:
1. Pixel size in mm (width and height)
2. The width of the imager in pixels
3. The width of the image output by the framegrabber
The pixel size can be found from the specifications of the imager. If you cannot find these, just use
defaults of 0.010 mm. The calibration will determine the pixel aspect ratio (width / height). The
calibrated lens focal length will not be correct because the pixel scale will be off, but that will not change
the validity of the calibration.
Figure 4-4 Smallv calibration dialog window.