---
title: TrackOpticalFlowRequest
framework: vision
role: symbol
role_heading: Class
path: vision/trackopticalflowrequest
---

# TrackOpticalFlowRequest

A request that determines the direction change of vectors for each pixel from a previous to current image.

## Declaration

```swift
final class TrackOpticalFlowRequest
```

## Overview

Overview This request generates an OpticalFlowObservation object that describes the directional change from image to image. The request works at the pixel level, so both images needs to have the same dimensions to successfully perform the request. important: Optical flow requests are very resource intensive, so perform only one request at a time. Release memory immediately after generating an optical flow.

## Topics

### Creating a request

- [init(_:frameAnalysisSpacing:)](vision/trackopticalflowrequest/init(_:frameanalysisspacing:).md)

### Performing a request

- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-80bya.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-3f3f1.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-qxxx.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-xspx.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-3hddl.md)
- [perform(on:orientation:)](vision/imageprocessingrequest/perform(on:orientation:)-85ex1.md)

### Understanding the result

- [OpticalFlowObservation](vision/opticalflowobservation.md)

### Configuring a request

- [computationAccuracy](vision/trackopticalflowrequest/computationaccuracy-swift.property.md)
- [TrackOpticalFlowRequest.ComputationAccuracy](vision/trackopticalflowrequest/computationaccuracy-swift.enum.md)
- [outputPixelFormatType](vision/trackopticalflowrequest/outputpixelformattype.md)
- [supportedOutputPixelFormatTypes](vision/trackopticalflowrequest/supportedoutputpixelformattypes.md)

### Getting the revision

- [revision](vision/trackopticalflowrequest/revision-swift.property.md)
- [supportedRevisions](vision/trackopticalflowrequest/supportedrevisions.md)
- [TrackOpticalFlowRequest.Revision](vision/trackopticalflowrequest/revision-swift.enum.md)

## Relationships

### Conforms To

- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [ImageProcessingRequest](vision/imageprocessingrequest.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)
- [StatefulRequest](vision/statefulrequest.md)
- [TargetedRequest](vision/targetedrequest.md)
- [VisionRequest](vision/visionrequest.md)

## See Also

### Motion and object tracking

- [DetectTrajectoriesRequest](vision/detecttrajectoriesrequest.md)
- [TrackObjectRequest](vision/trackobjectrequest.md)
- [TrackRectangleRequest](vision/trackrectanglerequest.md)