iOS Computer Vision Router

You MUST use this skill for ANY computer vision work using the Vision framework.

When to Use

Use this router when:

• Analyzing images or video
• Detecting objects, faces, or people
• Tracking hand or body pose
• Segmenting people or subjects
• Lifting subjects from backgrounds
• Recognizing text in images (OCR)
• Detecting barcodes or QR codes
• Scanning documents
• Using VisionKit or DataScannerViewController

Routing Logic

Vision Work

Implementation patterns → /skill axiom-vision

• Subject segmentation (VisionKit)
• Hand pose detection (21 landmarks)
• Body pose detection (2D/3D)
• Person segmentation
• Face detection
• Isolating objects while excluding hands
• Text recognition (VNRecognizeTextRequest)
• Barcode/QR detection (VNDetectBarcodesRequest)
• Document scanning (VNDocumentCameraViewController)
• Live scanning (DataScannerViewController)
• Structured document extraction (RecognizeDocumentsRequest, iOS 26+)

API reference → /skill axiom-vision-ref

• Complete Vision framework API
• VNDetectHumanHandPoseRequest
• VNDetectHumanBodyPoseRequest
• VNGenerateForegroundInstanceMaskRequest
• VNRecognizeTextRequest (fast/accurate modes)
• VNDetectBarcodesRequest (symbologies)
• DataScannerViewController delegates
• RecognizeDocumentsRequest (iOS 26+)
• Coordinate conversion patterns

Diagnostics → /skill axiom-vision-diag

• Subject not detected
• Hand pose missing landmarks
• Low confidence observations
• Performance issues
• Coordinate conversion bugs
• Text not recognized or wrong characters
• Barcodes not detected
• DataScanner showing blank or no items
• Document edges not detected

Decision Tree

1. Implementing (pose, segmentation, OCR, barcodes, documents, live scanning)? → vision
2. Need API reference / code examples? → vision-ref
3. Debugging issues (detection failures, confidence, coordinates)? → vision-diag

Anti-Rationalization

Thought	Reality
"Vision framework is just a request/handler pattern"	Vision has coordinate conversion, confidence thresholds, and performance gotchas. vision covers them.
"I'll handle text recognition without the skill"	VNRecognizeTextRequest has fast/accurate modes and language-specific settings. vision has the patterns.
"Subject segmentation is straightforward"	Instance masks have HDR compositing and hand-exclusion patterns. vision covers complex scenarios.

Critical Patterns

vision:

• Subject segmentation with VisionKit
• Hand pose detection (21 landmarks)
• Body pose detection (2D/3D, up to 4 people)
• Isolating objects while excluding hands
• CoreImage HDR compositing
• Text recognition (fast vs accurate modes)
• Barcode detection (symbology selection)
• Document scanning with perspective correction
• Live scanning with DataScannerViewController
• Structured document extraction (iOS 26+)

vision-diag:

• Subject detection failures
• Landmark tracking issues
• Performance optimization
• Observation confidence thresholds
• Text recognition failures (language, contrast)
• Barcode detection issues (symbology, distance)
• DataScanner troubleshooting
• Document edge detection problems

Example Invocations

User: "How do I detect hand pose in an image?"
→ Invoke: /skill axiom-vision

User: "Isolate a subject but exclude the user's hands"
→ Invoke: /skill axiom-vision

User: "How do I read text from an image?"
→ Invoke: /skill axiom-vision

User: "Scan QR codes with the camera"
→ Invoke: /skill axiom-vision

User: "How do I implement document scanning?"
→ Invoke: /skill axiom-vision

User: "Use DataScannerViewController for live text"
→ Invoke: /skill axiom-vision

User: "Subject detection isn't working"
→ Invoke: /skill axiom-vision-diag

User: "Text recognition returns wrong characters"
→ Invoke: /skill axiom-vision-diag

User: "Barcode not being detected"
→ Invoke: /skill axiom-vision-diag

User: "Show me VNDetectHumanBodyPoseRequest examples"
→ Invoke: /skill axiom-vision-ref

User: "What symbologies does VNDetectBarcodesRequest support?"
→ Invoke: /skill axiom-vision-ref

User: "RecognizeDocumentsRequest API reference"
→ Invoke: /skill axiom-vision-ref