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When the axis of your camera is perpendicular to the image plane and lens 
distortion is negligible, use simple calibration. In simple calibration, a pixel 
coordinate is transformed to a real-world coordinate through scaling in the 
horizontal and vertical directions. 

Use simple calibration to map pixel coordinates to real-world coordinates 
directly without a calibration grid. The software rotates and scales a pixel 
coordinate according to predefined coordinate reference and scaling 
factors. You can assign the calibration to an arbitrary image using 

imaqSetSimpleCalibration()

.

To perform a simple calibration, set a coordinate reference (angle, center, 
and axis direction) and scaling factors on the defined axis, as shown in 
Figure 6-7. Express the angle between the x-axis and the horizontal axis 
of the image in degrees. Express the center as the position, in pixels, where 
you want the coordinate reference origin. Set the axis direction to direct or 
indirect. Simple calibration also offers a correction table option and a 
scaling mode option.

Use the system parameter to define the coordinate system. Use the grid 
parameter to specify the scaling factors. Use the method parameter to set 
the scaling method. Set the learnTable parameter to 

TRUE

 to learn the 

correction table.

Figure 6-7.  Defining a Simple Calibration

1

Origin

X

Y

dy

1

dx