How Does the Caliper Tool Computes the Edge Points?

Updated Sep 10, 2020

Reported In


  • Vision Builder for Automated Inspection

Issue Details

I want to know how the distance between two points in a picture is computed when using the Caliper function in the NI Vision Builder for Automated Inspection.


The Caliper tool goes from one end to the other in the Region of Interest (ROI) checking the value of each pixel. When it detects a value change, it interprets there's a change in the geometry of the object in the picture and computes the distance.

The intensity of the values changes of the pixels inside the ROI can be seen in the Edge Strength Profile windows.