## REMOVED Requirements

### Requirement: Legacy PDF Generator Service

**Reason**: `pdf_generator.py` (507 lines) was the original PDF generation implementation using Pandoc/WeasyPrint. It has been completely superseded by `pdf_generator_service.py` which uses ReportLab for low-level PDF generation with full layout preservation, table rendering, and image support.

**Migration**: No migration needed. The new `pdf_generator_service.py` provides all functionality with improved features.

#### Scenario: Legacy PDF generator file removal
- **WHEN** the legacy `pdf_generator.py` file is removed
- **THEN** the system continues to function normally using `pdf_generator_service.py`
- **AND** PDF generation works correctly with layout preservation
- **AND** no import errors occur in any service or router

### Requirement: Deprecated IoU Configuration Parameters

**Reason**: `gap_filling_iou_threshold` and `gap_filling_dedup_iou_threshold` are deprecated configuration parameters that should be replaced by IoA (Intersection over Area) thresholds for better accuracy.

**Migration**: Use `gap_filling_dedup_ioa_threshold` instead.

#### Scenario: Deprecated config removal
- **WHEN** the deprecated IoU configuration parameters are removed from config.py
- **THEN** gap filling service uses IoA-based thresholds
- **AND** the system starts without configuration errors

## ADDED Requirements

### Requirement: Unified Bbox Utility Module

The system SHALL provide a centralized bbox utility module (`backend/app/utils/bbox_utils.py`) for consistent bounding box normalization across all services.

#### Scenario: Bbox normalization from polygon format
- **WHEN** a bbox in polygon format `[[x1,y1], [x2,y2], [x3,y3], [x4,y4]]` is provided
- **THEN** the utility returns normalized tuple `(x0, y0, x1, y1)` representing min/max coordinates

#### Scenario: Bbox normalization from flat array
- **WHEN** a bbox in flat array format `[x0, y0, x1, y1]` is provided
- **THEN** the utility returns normalized tuple `(x0, y0, x1, y1)`

#### Scenario: Bbox normalization from 8-point polygon
- **WHEN** a bbox in 8-point format `[x1, y1, x2, y2, x3, y3, x4, y4]` is provided
- **THEN** the utility calculates and returns normalized tuple `(min_x, min_y, max_x, max_y)`