.. _ChapterMetrics:

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Metrics
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Metrics are the individual qualities related to the image or subject being analyzed by PreFace.
Most Metrics are evaluated on demand when requested specifically through the PreFace API or when evaluating Compliance with a Profile.

Metric scores returned by PreFace are always greater than or equal to their Minimum and less than or equal to their Maximum allowable values.
In addition to a Minimum and Maximum value, some Metrics have a Correctable Minimum and Correctable Maximum value.
When specified in a Profile, the Correctable Minimum and Maximum determine the range of values that are allowed to be corrected during the Construction process.

Metrics are organized by category when used in a Profile.
The Metric categories are :
  - Face Characteristics
  - Eye Characteristics
  - Image Characteristics
  - Anomalies
  - Image Geometry
  - Demographics
  - Image Storage

.. include:: awpreface-sdk-auto-metrics.rst