Perform a Simple Calibration

1. Click Image»Image Calibration or select Image Calibration in the Image tab of the Processing Functions palette.
2. Select Simple Calibration and click OK.
3. Select the Pixel Type that applies to the camera.
4. Click Next.
5. Select two points. You can select points that were defined by previous inspection steps by double-clicking the point in the list or clicking the point in the image. You also can define new points by clicking unspecified pixels in the image.
   • If you selected square pixels in the previous wizard step, enter the distance between the two selected points in real-world units and specify the correct unit. Proceed to the next step.
   • If you selected nonsquare pixels in the previous step, follow these instructions:
     1. Enter the x projection of the two points in real-world units and specify the correct unit.
     2. Click Next.
     3. If you want to use different points to specify the pixel ratio along the y-axis, select two other points. Otherwise, go to the next substep.
     4. Enter the y projection of the two points in real-world units and specify the correct unit.
6. Click Next.
7. Select the origin of the calibration axis by entering the X- and Y-coordinates or by selecting an Existing Point from the list.
8. Select the User-Defined Angle of the calibration or select an Existing Angle. If you choose an Existing Angle from the list, you can add 90°, 180°, or 270° to the value.
9. Select an Axis Reference.
10. Click OK to apply the calibration.
11. Click OK to save the step in the script and close the Setup window.

Note  To save an image calibrated with Simple Calibration, complete the following steps. Click File»Save Image. In the Save Image window, select a location to save the image. Enter a name in the File Name textbox. Enable the Save Extra Information control. Click Save.

Control Descriptions

• Open Image—Image on which you specify points to base the calibration. This image must be the same size as the image you want to calibrate. Vision Assistant does not run the script on this image.
• Pixel Type—Square or nonsquare pixels.
• List of points—Points defined in the image that you can use to calibrate the image.
• Point X and Y—Coordinates of the selected points.
• Length—Distance, in pixels, between the two selected points. This control appears only when you set Pixel Type to Square.
• dX—Projection of the segment specified by the two points onto the x-axis. This control appears only when you set Pixel Type to Nonsquare.
• dY—Projection of the segment specified by the two points onto the y-axis. This control appears only when you set Pixel Type to Nonsquare.
• Unit—Real-world unit of the measurement.
• Axis Origin
  • User Defined—X- and y-coordinates of the pixel that you want to use as the calibration axis origin.
  • Existing Point—Point defined in a previous step that you want to use as the calibration axis origin.
• X Axis Angle
  • User Defined—Angle you want to use between the x-axis of the calibration axes and the horizontal axis of the image.
  • Existing Angle—Angle defined in a previous step that you want to use between the x-axis of the calibration axes and the horizontal axis of the image. You can select a value from the + control to add to the Angle value.
• Axis Reference—Direction of the y-axis.