Extend keyboard navigation to support panel mode when enabled.
Changes:
- Check for panel-mode attribute before routing key events
- Route Arrow keys and Vim keys (h/l) to panel navigation in panel mode
- Add 'P' key to toggle panel mode
- Add 'Escape' key to exit panel mode
- Maintain backward compatibility with existing page navigation
When panel mode is active:
- ArrowRight/l: next panel
- ArrowLeft/h: previous panel
- Escape/P: exit panel mode
When panel mode is inactive:
- ArrowRight/l: next page (existing behavior)
- ArrowLeft/h: previous page (existing behavior)
- P: enter panel mode (new feature)
Implement a comprehensive panel detection system for manga and comics
with automatic fallback chain for maximum compatibility.
Core detector (detector.js):
- PanelDetector class with in-memory caching
- Lazy-loading of OpenCV and TensorFlow.js
- Validation logic to filter poor detections
- Cache management to avoid re-detection
OpenCV edge detection (opencv.js):
- Canny edge detection for panel boundaries
- Contour finding with bounding box extraction
- Size and aspect ratio filtering
- Reading order sorting (top-to-bottom, left-to-right)
ML-based detection (coco-ssd.js):
- COCO-SSD pre-trained model integration
- Object detection for irregular panel layouts
- Rectangular filtering for panel-like regions
- Handles edge cases where edge detection fails
Grid-based fallback (grid.js):
- Lightweight 3x3 grid detection
- Empty cell detection via alpha channel analysis
- Adjacent panel merging algorithm
- Always works as final fallback
The detection pipeline tries OpenCV first (fast, accurate),
falls back to ML detection if validation fails,
and uses grid detection as ultimate baseline.
john-okeefe