tfm_ainventory/dev_docs/SCANNER_LOGIC_SPEC.md

TFM aInventory - Scanner Technical Specification (v1.2)

This document defines the "Frozen" parameters for the scanner component. Do NOT modify these values without explicit user approval.

1. Hardware Access

• API: Direct MediaStreamTrack access for high-performance camera control.
• Zoom: Dynamic detection of capabilities.zoom.max.
• Zoom Cycle: 1x -> 2x -> Max/2 -> Max.

2. Image Pre-processing (The OCR "Secret Sauce")

Before being sent to Tesseract.js, every frame undergoes these transformations:

• Rescaling: Fixed canvas width of 1200px (Optimal for Mobile RAM/Accuracy).
• Cropping: 60% Center Crop of the video stream (forces focus & removes peripheral noise).
• Filters: grayscale(100%) contrast(180%) brightness(105%).
• Format: High-quality JPEG (0.85 quality) via toDataURL.

3. OCR Matching Engine (page.tsx)

• Sanitization: Text normalized to UPPERCASE, non-alphanumeric replaced with spaces.
• Noise Filtering:
  • Tokens < 3 chars ignored.
  • Decimals (e.g., 0.11, 0.18) ignored via regex: /^\d+\.\d+$/.
  • Dates (e.g., 2024-07-25) ignored via regex: /^\d{2,4}-\d{2}-\d{2}$/.
• Scoring System:
  • Exact Serial Number Match: +500 points (Instant Match).
  • Exact Part Number Match: +200 points.
  • Token match (e.g., "LC" in "LC/UPC"): +50 points.
  • Category Match: +20 points.
• Threshold: Minimum 40 points required for automatic match without user intervention.

4. UI/UX Flow

1. Auto-Match: Attempt to identify item immediately from raw text.
2. Interactive Selection (Fallback): If match confidence is low, freeze frame and show clickable bounding boxes for manual word selection.

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Created: 2026-04-10 Status: FROZEN