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# SaliencyImageObservation

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

```
struct SaliencyImageObservation
```

## Topics

### Creating an observation

[`init?(VNSaliencyImageObservation)`](/documentation/Vision/SaliencyImageObservation/init(_:))

Creates a saliency image observation.

### Inspecting an observation

[`enum RequestDescriptor`](/documentation/Vision/RequestDescriptor)

A type that describes the request and revision combination.

[`let heatMap: PixelBufferObservation`](/documentation/Vision/SaliencyImageObservation/heatMap)

A grayscale heat map of important areas across the image.

[`struct PixelBufferObservation`](/documentation/Vision/PixelBufferObservation)

An object that represents an image that an image-analysis request produces.

[`let salientObjects: [RectangleObservation]`](/documentation/Vision/SaliencyImageObservation/salientObjects)

A collection of objects describing the distinct areas of the saliency heat map.

[`struct RectangleObservation`](/documentation/Vision/RectangleObservation)

An object that represents the four vertices of a detected rectangle.

## Relationships

### Conforms To

[`Encodable`](/documentation/Swift/Encodable)

[`Sendable`](/documentation/Swift/Sendable)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`Escapable`](/documentation/Swift/Escapable)

[`Equatable`](/documentation/Swift/Equatable)

[`Hashable`](/documentation/Swift/Hashable)

[`Decodable`](/documentation/Swift/Decodable)

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

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Copyable`](/documentation/Swift/Copyable)

---

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