---
title: VNSaliencyImageObservation
framework: vision
role: symbol
role_heading: Class
path: vision/vnsaliencyimageobservation
---

# VNSaliencyImageObservation

An observation that contains a grayscale heat map of important areas across an image.

## Declaration

```swift
class VNSaliencyImageObservation
```

## Overview

Overview The heat map is a CVPixelBuffer in a one-component floating-point pixel format. Its dimensions are 64 x 64 when fetched in real time, or 68 x 68 when requested in its deferred form.

## Topics

### Locating Salient Regions

- [salientObjects](vision/vnsaliencyimageobservation/salientobjects.md)

## Relationships

### Inherits From

- [VNPixelBufferObservation](vision/vnpixelbufferobservation.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

### Saliency analysis

- [Cropping Images Using Saliency](vision/cropping-images-using-saliency.md)
- [Highlighting Areas of Interest in an Image Using Saliency](vision/highlighting-areas-of-interest-in-an-image-using-saliency.md)
- [VNGenerateAttentionBasedSaliencyImageRequest](vision/vngenerateattentionbasedsaliencyimagerequest.md)
- [VNGenerateObjectnessBasedSaliencyImageRequest](vision/vngenerateobjectnessbasedsaliencyimagerequest.md)