# Geometry

The analysis mode to use when comparing the source media to 2-D objects in the training database.

Objects in media that you analyze may appear different to the training images you supplied, because the objects can be subject to various transformations and perspective distortion.

Set this parameter to one of the following options:

- `AFF2` - Use this option to find 2-D objects with out-of-plane rotation, when the objects are expected to be small compared to the distance from the camera (so the objects take up a small part of the image, or the camera has a long focal length). The AFF2 algorithm assumes that parallel lines stay approximately parallel. If the objects are large and close to the camera, use `HOMOGRAPHY` instead. If you don't expect out-of-plane rotation, use `SIM2` instead.
- `HOMOGRAPHY` - Use this option when the focal length of the camera is unknown and some perspective distortion is expected but the object is 2-D (rigid and flat).
- `SIM2` - Use this option when you want to allow only rotation and translation when compared to the training image. Out-of-plane rotation is not expected in this mode, so objects that have out-of-plane rotation are not recognized.

Type: | String
Default: | HOMOGRAPHY
Required: | No
Configuration Section: | TaskName
Example: | `Geometry=SIM2`
See Also: | Geometry3

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