<!--
{
  "availability" : [
    "iOS: 18.0.0 -",
    "iPadOS: 18.0.0 -",
    "macOS: 15.0.0 -",
    "tvOS: 18.0.0 -",
    "visionOS: 2.0.0 -",
    "watchOS: 27.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Vision",
  "identifier" : "/documentation/Vision/ImageHomographicAlignmentObservation",
  "metadataVersion" : "0.1.0",
  "role" : "Structure",
  "symbol" : {
    "kind" : "Structure",
    "modules" : [
      "Vision"
    ],
    "preciseIdentifier" : "s:6Vision36ImageHomographicAlignmentObservationV"
  },
  "title" : "ImageHomographicAlignmentObservation"
}
-->

# ImageHomographicAlignmentObservation

An object that represents a perspective warp transformation.

```
struct ImageHomographicAlignmentObservation
```

## Overview

This type of observation results from a [`TrackHomographicImageRegistrationRequest`](/documentation/Vision/TrackHomographicImageRegistrationRequest), informing the [`warpTransform`](/documentation/Vision/ImageHomographicAlignmentObservation/warpTransform) performed to align the input images.

## Topics

### Creating an observation

[`init(VNImageHomographicAlignmentObservation)`](/documentation/Vision/ImageHomographicAlignmentObservation/init(_:))

Creates a homographic alignment observation.

### Inspecting an observation

[`let warpTransform: matrix_float3x3`](/documentation/Vision/ImageHomographicAlignmentObservation/warpTransform)

The warp transform matrix to morph the floating image into the reference image.

### Applying a transform

[`func applyTransform(to: CIImage) -> CIImage`](/documentation/Vision/ImageHomographicAlignmentObservation/applyTransform(to:))

Applies the transform to an image.

## Relationships

### Conforms To

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

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

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

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

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

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

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

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

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

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

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)