Caliper Tool Overview
The Caliper tool is a vision tool for measuring the width of objects, the location of edges or features, and the location and spacing of pairs of edges in images. The Caliper tool differs from other vision tools in that it requires that you know the approximate location and characteristics of the feature or edges you want to measure or locate.
The Caliper tool is typically used to develop detailed information about the precise locations of features within an object. It is not appropriate for developing information about the shape of objects or features.
The Caliper tool supports the following two methods of locating edges or edge pairs in an image:
- Edge mode, in which edge peaks are detected using a simple 1-D kernel
- Correlation mode, in which correlation peaks between a 1-D sample image and a 1-D reference image are located
Once you have determined the location and orientation of the edge or edge pair of interest within the image, you perform the following steps to apply the Caliper tool:
- Specify a projection region that encloses the edges or edge pairs of interest.
- For edge mode
- Select a filter size and contrast threshold that isolate the edges of interest.
- Define an edge model that describes the edge or edge pair of interest.
- For correlation mode
- Supply a one-dimensional reference image.
- Define the scoring methods that are used to score edge pattern candidates within the image.
- Apply the Caliper tool and interpret the results.