/axiom-vision

name: axiom-vision
description: Use when implementing ANY computer vision feature — image analysis, pose detection, person segmentation, subject lifting, text recognition, barcode scanning.
license: MIT

Computer Vision

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

Quick Reference

| Symptom / Task | Reference | |----------------|-----------| | Subject segmentation, lifting | See `skills/vision-framework.md` | | Hand/body pose detection | See `skills/vision-framework.md` | | Text recognition (OCR) | See `skills/vision-framework.md` | | Barcode/QR code detection | See `skills/vision-framework.md` | | Document scanning | See `skills/vision-framework.md` | | DataScannerViewController | See `skills/vision-framework.md` | | Structured document extraction (iOS 26+) | See `skills/vision-framework.md` | | Isolate object excluding hand | See `skills/vision-framework.md` | | Tap-to-segment any object `OS27` | See `skills/vision-ref.md` | | Vision on watchOS `watchOS27` | See `skills/vision-ref.md` | | Vision tools for Foundation Models (BarcodeReaderTool, OCRTool) `OS27` | See `skills/vision-ref.md` | | Vision framework API reference | See `skills/vision-ref.md` | | Visual Intelligence integration (iOS 26+, iPadOS27/macOS27) | See `skills/vision-ref.md` | | Sensitive content classification (nudity/gore/violence), categorized via `detectedTypes` (`OS27`) | See `skills/vision-ref.md` | | Group/cluster faces into people across a library, video highlights/key frames (`OS27`) | Use axiom-media (skills/media-intelligence.md) instead — MediaIntelligence clusters identities; Vision detects faces in one image | | Subject not detected | See `skills/vision-diag.md` | | Hand/body pose missing landmarks | See `skills/vision-diag.md` | | Low confidence observations | See `skills/vision-diag.md` | | UI freezing during processing | See `skills/vision-diag.md` | | Coordinate conversion bugs | See `skills/vision-diag.md` | | Text not recognized / wrong chars | See `skills/vision-diag.md` | | Barcode not detected | See `skills/vision-diag.md` | | DataScanner blank / no items | See `skills/vision-diag.md` | | Document edges not detected | See `skills/vision-diag.md` |

Decision Tree

digraph vision {
    start [label="Computer vision task" shape=ellipse];
    what [label="What do you need?" shape=diamond];

    start -> what;
    what -> "skills/vision-framework.md" [label="implement feature"];
    what -> "skills/vision-ref.md" [label="API reference"];
    what -> "skills/vision-ref.md" [label="Visual Intelligence"];
    what -> "skills/vision-ref.md" [label="tap-to-segment / watchOS / FM tools (27)"];
    what -> "skills/vision-diag.md" [label="something broken"];
}

1. Implementing (pose, segmentation, OCR, barcodes, documents, live scanning)? → `skills/vision-framework.md` 2. Visual Intelligence system integration (camera/screenshot search; iOS 26+, iPadOS27/macOS27)? → `skills/vision-ref.md` (Visual Intelligence section) 3. Tap-to-segment, Vision on watchOS, or Vision tools for Foundation Models (27 cycle)? → `skills/vision-ref.md` 4. Need API reference / code examples? → `skills/vision-ref.md` 5. Debugging issues (detection failures, confidence, coordinates)? → `skills/vision-diag.md`

Critical Patterns

**Implementation** (`skills/vision-framework.md`):

• Decision tree for choosing the right Vision API
• Subject segmentation with VisionKit
• Isolating objects while excluding hands (combining APIs)
• Hand/body pose detection (21/19 landmarks)
• Text recognition (fast vs accurate modes)
• Barcode detection with symbology selection
• Document scanning and structured extraction (iOS 26+)
• Live scanning with DataScannerViewController
• CoreImage HDR compositing

**Diagnostics** (`skills/vision-diag.md`):

• Subject detection failures (edge of frame, lighting)
• Landmark tracking issues (confidence thresholds)
• Performance optimization (frame skipping, downscaling)
• Coordinate conversion (lower-left vs top-left origin)
• Text recognition failures (language, contrast)
• Barcode detection issues (symbology, size, glare)
• DataScanner troubleshooting (availability, data types)

Anti-Rationalization

| Thought | Reality | |---------|---------| | "Vision framework is just a request/handler pattern" | Vision has coordinate conversion, confidence thresholds, and performance gotchas. vision-framework.md covers them. | | "I'll handle text recognition without the skill" | VNRecognizeTextRequest has fast/accurate modes and language-specific settings. vision-framework.md has the patterns. | | "Subject segmentation is straightforward" | Instance masks have HDR compositing and hand-exclusion patterns. vision-framework.md covers complex scenarios. | | "Visual Intelligence is just the camera API" | Visual Intelligence is a system-level feature requiring IntentValueQuery and SemanticContentDescriptor. vision-ref.md has the integration section. | | "I'll just process on the main thread" | Vision blocks UI on older devices. Users on iPhone 12 will experience frozen app. 15 min to add background queue. |

Example Invocations

User: "How do I detect hand pose in an image?" → See `skills/vision-framework.md`

User: "Isolate a subject but exclude the user's hands" → See `skills/vision-framework.md`

User: "How do I read text from an image?" → See `skills/vision-framework.md`

User: "Scan QR codes with the camera" → See `skills/vision-framework.md`

User: "Subject detection isn't working" → See `skills/vision-diag.md`

User: "Text recognition returns wrong characters" → See `skills/vision-diag.md`

User: "Show me VNDetectHumanBodyPoseRequest examples" → See `skills/vision-ref.md`

User: "How do I make my app work with Visual Intelligence?" → See `skills/vision-ref.md`

User: "Let users tap an object in a photo to cut it out" → See `skills/vision-ref.md` (Iterative Segmentation)

User: "Can I use Vision in my watchOS app?" → See `skills/vision-ref.md` (Vision on