---
title: VNHorizonObservation
framework: vision
role: symbol
role_heading: Class
path: vision/vnhorizonobservation
---

# VNHorizonObservation

The horizon angle information that an image-analysis request detects.

## Declaration

```swift
class VNHorizonObservation
```

## Overview

Overview Instances of this class result from invoking a VNDetectHorizonRequest, and report the angle and transform of the horizon in an image.

## Topics

### Evaluating the Horizon

- [angle](vision/vnhorizonobservation/angle.md)
- [transform](vision/vnhorizonobservation/transform.md)
- [transform(forImageWidth:height:)](vision/vnhorizonobservation/transform(forimagewidth:height:).md)

## Relationships

### Inherits From

- [VNObservation](vision/vnobservation.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSecureCoding](foundation/nssecurecoding.md)
- [VNRequestRevisionProviding](vision/vnrequestrevisionproviding.md)

## See Also

### Horizon detection

- [VNDetectHorizonRequest](vision/vndetecthorizonrequest.md)