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# VNDetectContoursRequest

A request that detects the contours of the edges of an image.

```
class VNDetectContoursRequest
```

## Topics

### Configuring the Request

[`contrastAdjustment`](/documentation/Vision/VNDetectContoursRequest/contrastAdjustment)

The amount by which to adjust the image contrast.

[`contrastPivot`](/documentation/Vision/VNDetectContoursRequest/contrastPivot)

The pixel value to use as a pivot for the contrast.

[`detectsDarkOnLight`](/documentation/Vision/VNDetectContoursRequest/detectsDarkOnLight)

A Boolean value that indicates whether the request detects a dark object on a light background to aid in detection.

[`maximumImageDimension`](/documentation/Vision/VNDetectContoursRequest/maximumImageDimension)

The maximum image dimension to use for contour detection.

[`detectDarkOnLight`](/documentation/Vision/VNDetectContoursRequest/detectDarkOnLight)

A Boolean value that indicates whether the request detects a dark object on a light background.

### Accessing the Results

[`results`](/documentation/Vision/VNDetectContoursRequest/results)

The results of the request to detect contours.

[`VNContoursObservation`](/documentation/Vision/VNContoursObservation)

An object that represents the detected contours in an image.

### Identifying Request Revisions

[`VNDetectContourRequestRevision1`](/documentation/Vision/VNDetectContourRequestRevision1)

A constant for specifying revision 1 of the contours detection request.


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