---
title: VNDetectContoursRequest
framework: vision
role: symbol
role_heading: Class
path: vision/vndetectcontoursrequest
---

# VNDetectContoursRequest

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

## Declaration

```swift
class VNDetectContoursRequest
```

## Topics

### Configuring the Request

- [contrastAdjustment](vision/vndetectcontoursrequest/contrastadjustment.md)
- [contrastPivot](vision/vndetectcontoursrequest/contrastpivot.md)
- [detectsDarkOnLight](vision/vndetectcontoursrequest/detectsdarkonlight.md)
- [maximumImageDimension](vision/vndetectcontoursrequest/maximumimagedimension.md)
- [detectDarkOnLight](vision/vndetectcontoursrequest/detectdarkonlight.md)

### Accessing the Results

- [results](vision/vndetectcontoursrequest/results.md)
- [VNContoursObservation](vision/vncontoursobservation.md)

### Identifying Request Revisions

- [VNDetectContourRequestRevision1](vision/vndetectcontourrequestrevision1.md)

## Relationships

### Inherits From

- [VNImageBasedRequest](vision/vnimagebasedrequest.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)