---
title: RequestDescriptor
framework: vision
role: symbol
role_heading: Enumeration
path: vision/requestdescriptor
---

# RequestDescriptor

A type that describes the request and revision combination.

## Declaration

```swift
enum RequestDescriptor
```

## Topics

### Getting the still-image descriptor

- [RequestDescriptor.classifyImageRequest(_:)](vision/requestdescriptor/classifyimagerequest(_:).md)
- [RequestDescriptor.detectLensSmudgeRequest(_:)](vision/requestdescriptor/detectlenssmudgerequest(_:).md)

### Getting the image sequence descriptor

- [RequestDescriptor.detectDocumentSegmentationRequest(_:)](vision/requestdescriptor/detectdocumentsegmentationrequest(_:).md)
- [RequestDescriptor.recognizeDocumentsRequest(_:)](vision/requestdescriptor/recognizedocumentsrequest(_:).md)
- [RequestDescriptor.generatePersonInstanceMaskRequest(_:)](vision/requestdescriptor/generatepersoninstancemaskrequest(_:).md)
- [RequestDescriptor.generatePersonSegmentationRequest(_:)](vision/requestdescriptor/generatepersonsegmentationrequest(_:).md)

### Getting the image aesthetics descriptor

- [RequestDescriptor.calculateImageAestheticsScoresRequest(_:)](vision/requestdescriptor/calculateimageaestheticsscoresrequest(_:).md)

### Getting the saliency descriptor

- [RequestDescriptor.generateAttentionBasedSaliencyImageRequest(_:)](vision/requestdescriptor/generateattentionbasedsaliencyimagerequest(_:).md)
- [RequestDescriptor.generateObjectnessBasedSaliencyImageRequest(_:)](vision/requestdescriptor/generateobjectnessbasedsaliencyimagerequest(_:).md)

### Getting the object-tracking descriptor

- [RequestDescriptor.trackObjectRequest(_:)](vision/requestdescriptor/trackobjectrequest(_:).md)
- [RequestDescriptor.trackRectangleRequest(_:)](vision/requestdescriptor/trackrectanglerequest(_:).md)

### Getting the face and body detection descriptor

- [RequestDescriptor.detectFaceCaptureQualityRequest(_:)](vision/requestdescriptor/detectfacecapturequalityrequest(_:).md)
- [RequestDescriptor.detectFaceLandmarksRequest(_:)](vision/requestdescriptor/detectfacelandmarksrequest(_:).md)
- [RequestDescriptor.detectFaceRectanglesRequest(_:)](vision/requestdescriptor/detectfacerectanglesrequest(_:).md)
- [RequestDescriptor.detectHumanRectanglesRequest(_:)](vision/requestdescriptor/detecthumanrectanglesrequest(_:).md)

### Getting the body and hand pose detection descriptor

- [RequestDescriptor.detectHumanBodyPoseRequest(_:)](vision/requestdescriptor/detecthumanbodyposerequest(_:).md)
- [RequestDescriptor.detectHumanHandPoseRequest(_:)](vision/requestdescriptor/detecthumanhandposerequest(_:).md)
- [RequestDescriptor.detectHumanBodyPose3DRequest(_:)](vision/requestdescriptor/detecthumanbodypose3drequest(_:).md)

### Getting the animal detection descriptor

- [RequestDescriptor.detectAnimalBodyPoseRequest(_:)](vision/requestdescriptor/detectanimalbodyposerequest(_:).md)
- [RequestDescriptor.recognizeAnimalsRequest(_:)](vision/requestdescriptor/recognizeanimalsrequest(_:).md)

### Getting the text descriptor

- [RequestDescriptor.detectTextRectanglesRequest(_:)](vision/requestdescriptor/detecttextrectanglesrequest(_:).md)
- [RequestDescriptor.recognizeTextRequest(_:)](vision/requestdescriptor/recognizetextrequest(_:).md)

### Getting the image alignment, feature print, and background removal descriptor

- [RequestDescriptor.trackTranslationalImageRegistrationRequest(_:)](vision/requestdescriptor/tracktranslationalimageregistrationrequest(_:).md)
- [RequestDescriptor.trackHomographicImageRegistrationRequest(_:)](vision/requestdescriptor/trackhomographicimageregistrationrequest(_:).md)
- [RequestDescriptor.generateForegroundInstanceMaskRequest(_:)](vision/requestdescriptor/generateforegroundinstancemaskrequest(_:).md)
- [RequestDescriptor.generateImageFeaturePrintRequest(_:)](vision/requestdescriptor/generateimagefeatureprintrequest(_:).md)

### Getting the trajectory, contour, and horizon detection descriptor

- [RequestDescriptor.detectTrajectoriesRequest(_:)](vision/requestdescriptor/detecttrajectoriesrequest(_:).md)
- [RequestDescriptor.detectContoursRequest(_:)](vision/requestdescriptor/detectcontoursrequest(_:).md)
- [RequestDescriptor.detectHorizonRequest(_:)](vision/requestdescriptor/detecthorizonrequest(_:).md)

### Getting the optical flow, rectangle and barcode detection descriptor

- [RequestDescriptor.trackOpticalFlowRequest(_:)](vision/requestdescriptor/trackopticalflowrequest(_:).md)
- [RequestDescriptor.detectRectanglesRequest(_:)](vision/requestdescriptor/detectrectanglesrequest(_:).md)
- [RequestDescriptor.detectBarcodesRequest(_:)](vision/requestdescriptor/detectbarcodesrequest(_:).md)

### Getting the machine learning image-analysis descriptor

- [RequestDescriptor.coreMLRequest(_:)](vision/requestdescriptor/coremlrequest(_:).md)

### Enumeration Cases

- [RequestDescriptor.generateIterativeSegmentationRequest(_:)](vision/requestdescriptor/generateiterativesegmentationrequest(_:).md)
- [RequestDescriptor.generateSelectedObjectSegmentationRequest(_:)](vision/requestdescriptor/generateselectedobjectsegmentationrequest(_:).md)

## Relationships

### Conforms To

- [CustomStringConvertible](swift/customstringconvertible.md)
- [Decodable](swift/decodable.md)
- [Encodable](swift/encodable.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Inspecting an observation

- [uuid](vision/visionobservation/uuid.md)
- [confidence](vision/visionobservation/confidence.md)
- [description](vision/visionobservation/description.md)
- [originatingRequestDescriptor](vision/visionobservation/originatingrequestdescriptor.md)
- [timeRange](vision/visionobservation/timerange.md)