# Edge Mode Scoring

Once it has located the edges in the original image, the Caliper tool computes a score for each potential edge pattern in the image. The score for each edge pattern in the image is computed based on the similarity between the edge pattern in the image and an ideal edge pattern that you define. The edge patterns in the image are called edge pattern candidates while the ideal edge pattern is called the edge model. You can define edge models that contain a single edge or a pair of edges.

You control the method that the Caliper tool uses to score edge pattern candidates by performing the following steps:

- Define the edge model that describes the edge or edge pair for which you are searching.
- Define one or more scoring methods that define how edge pattern candidates are to be evaluated for similarity to the edge model.

An edge model is a description of the edge pattern that you expect to see in the image. An edge model includes edge spacing, position, and polarity (dark to light or light to dark).

For each edge pattern candidate in the image, the Caliper tool computes a score. You can specify exactly how to evaluate each edge attribute, such as position, strength, or polarity, when computing the overall score for that edge. The tool computes a separate value for each attribute for each edge pattern candidate based on the scoring method that you supply, then computes an overall score for each edge pattern candidate by combining the individual scores.