Methodologydesign

axiom-vision

Use when implementing ANY computer vision feature — image analysis, pose detection, person segmentation, subject lifting, text recognition, barcode scanning.

charleswiltgen/axiom

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Install

npx skills add https://github.com/charleswiltgen/axiom --skill axiom-vision

Use with your agent

Install the axiom-vision skill, then use it as build context. Run: npx skills add https://github.com/charleswiltgen/axiom --skill axiom-vision. Then read the installed skill.md and follow its guidance to build or refactor my project.

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`
Vision framework API reference	See `skills/vision-ref.md`
Visual Intelligence integration (iOS 26+)	See `skills/vision-ref.md`
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-diag.md" [label="something broken"];
}

Implementing (pose, segmentation, OCR, barcodes, documents, live scanning)? → skills/vision-framework.md
Visual Intelligence system integration (camera feature, iOS 26+)? → skills/vision-ref.md (Visual Intelligence section)
Need API reference / code examples? → skills/vision-ref.md
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 (21/18 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: "RecognizeDocumentsRequest API reference" → See skills/vision-ref.md