24253ac15e
Backend changes: - Apply background image + invisible text layer to all Direct Track PDFs - Add CHART to regions_to_avoid for text extraction - Improve visual fidelity for native PDFs and Office documents Frontend changes: - Remove JSON, UnifiedDocument, Markdown download buttons - Simplify to 2-column layout with only Layout PDF and Reflow PDF - Remove translation JSON download and Layout PDF option - Keep only Reflow PDF for translated document downloads - Clean up unused imports (FileJson, Database, FileOutput) Archives two OpenSpec proposals: - unify-direct-track-pdf-rendering - simplify-frontend-export-options 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
184 lines
8.8 KiB
Markdown
184 lines
8.8 KiB
Markdown
# document-processing Specification
|
|
|
|
## Purpose
|
|
TBD - created by archiving change dual-track-document-processing. Update Purpose after archive.
|
|
## Requirements
|
|
### Requirement: Dual-track Processing
|
|
The system SHALL support two distinct processing tracks for documents: OCR track for scanned/image documents and Direct extraction track for editable PDFs.
|
|
|
|
#### Scenario: Process scanned PDF through OCR track
|
|
- **WHEN** a scanned PDF is uploaded
|
|
- **THEN** the system SHALL detect it requires OCR
|
|
- **AND** route it through PaddleOCR PP-StructureV3 pipeline
|
|
- **AND** return results in UnifiedDocument format
|
|
|
|
#### Scenario: Process editable PDF through direct extraction
|
|
- **WHEN** an editable PDF with extractable text is uploaded
|
|
- **THEN** the system SHALL detect it can be directly extracted
|
|
- **AND** route it through PyMuPDF extraction pipeline
|
|
- **AND** return results in UnifiedDocument format without OCR
|
|
|
|
#### Scenario: Auto-detect processing track
|
|
- **WHEN** a document is uploaded without explicit track specification
|
|
- **THEN** the system SHALL analyze the document type and content
|
|
- **AND** automatically select the optimal processing track
|
|
- **AND** include the selected track in processing metadata
|
|
|
|
### Requirement: Document Type Detection
|
|
The system SHALL provide intelligent document type detection to determine the optimal processing track.
|
|
|
|
#### Scenario: Detect editable PDF
|
|
- **WHEN** analyzing a PDF document
|
|
- **THEN** the system SHALL check for extractable text content
|
|
- **AND** return confidence score for editability
|
|
- **AND** recommend "direct" track if text coverage > 90%
|
|
|
|
#### Scenario: Detect scanned document
|
|
- **WHEN** analyzing an image or scanned PDF
|
|
- **THEN** the system SHALL identify lack of extractable text
|
|
- **AND** recommend "ocr" track for processing
|
|
- **AND** configure appropriate OCR models
|
|
|
|
#### Scenario: Detect Office documents
|
|
- **WHEN** analyzing .docx, .xlsx, .pptx files
|
|
- **THEN** the system SHALL identify Office format
|
|
- **AND** route to OCR track for initial implementation
|
|
- **AND** preserve option for future direct Office extraction
|
|
|
|
### Requirement: Unified Document Model
|
|
The system SHALL use a standardized UnifiedDocument model as the common output format for both processing tracks.
|
|
|
|
#### Scenario: Generate UnifiedDocument from OCR
|
|
- **WHEN** OCR processing completes
|
|
- **THEN** the system SHALL convert PP-StructureV3 results to UnifiedDocument
|
|
- **AND** preserve all element types, coordinates, and confidence scores
|
|
- **AND** maintain reading order and hierarchical structure
|
|
|
|
#### Scenario: Generate UnifiedDocument from direct extraction
|
|
- **WHEN** direct extraction completes
|
|
- **THEN** the system SHALL convert PyMuPDF results to UnifiedDocument
|
|
- **AND** preserve text styling, fonts, and exact positioning
|
|
- **AND** extract tables with cell boundaries and content
|
|
|
|
#### Scenario: Consistent output regardless of track
|
|
- **WHEN** processing completes through either track
|
|
- **THEN** the output SHALL conform to UnifiedDocument schema
|
|
- **AND** include processing_track metadata field
|
|
- **AND** support identical downstream operations (PDF generation, translation)
|
|
|
|
### Requirement: Enhanced OCR with Full PP-StructureV3
|
|
The system SHALL utilize the full capabilities of PP-StructureV3, extracting all 23 element types from parsing_res_list, with proper handling of visual elements and table coordinates.
|
|
|
|
#### Scenario: Extract comprehensive document structure
|
|
- **WHEN** processing through OCR track
|
|
- **THEN** the system SHALL use page_result.json['parsing_res_list']
|
|
- **AND** extract all element types including headers, lists, tables, figures
|
|
- **AND** preserve layout_bbox coordinates for each element
|
|
|
|
#### Scenario: Maintain reading order
|
|
- **WHEN** extracting elements from PP-StructureV3
|
|
- **THEN** the system SHALL preserve the reading order from parsing_res_list
|
|
- **AND** assign sequential indices to elements
|
|
- **AND** support reordering for complex layouts
|
|
|
|
#### Scenario: Extract table structure
|
|
- **WHEN** PP-StructureV3 identifies a table
|
|
- **THEN** the system SHALL extract cell content and boundaries
|
|
- **AND** validate cell_boxes coordinates against page boundaries
|
|
- **AND** apply fallback detection for invalid coordinates
|
|
- **AND** preserve table HTML for structure
|
|
- **AND** extract plain text for translation
|
|
|
|
#### Scenario: Extract visual elements with paths
|
|
- **WHEN** PP-StructureV3 identifies visual elements (IMAGE, FIGURE, CHART, DIAGRAM)
|
|
- **THEN** the system SHALL preserve saved_path for each element
|
|
- **AND** include image dimensions and format
|
|
- **AND** enable image embedding in output PDF
|
|
|
|
### Requirement: Structure-Preserving Translation Foundation
|
|
The system SHALL maintain document structure and layout information to support future translation features.
|
|
|
|
#### Scenario: Preserve coordinates for translation
|
|
- **WHEN** processing any document
|
|
- **THEN** the system SHALL retain bbox coordinates for all text elements
|
|
- **AND** calculate space requirements for text expansion/contraction
|
|
- **AND** maintain element relationships and groupings
|
|
|
|
#### Scenario: Extract translatable content
|
|
- **WHEN** processing tables and lists
|
|
- **THEN** the system SHALL extract plain text content
|
|
- **AND** maintain mapping to original structure
|
|
- **AND** preserve formatting markers for reconstruction
|
|
|
|
#### Scenario: Support layout adjustment
|
|
- **WHEN** preparing for translation
|
|
- **THEN** the system SHALL identify flexible vs fixed layout regions
|
|
- **AND** calculate maximum text expansion ratios
|
|
- **AND** preserve non-translatable elements (logos, signatures)
|
|
|
|
### Requirement: Generate UnifiedDocument from direct extraction
|
|
The system SHALL convert PyMuPDF results to UnifiedDocument with correct table cell merging.
|
|
|
|
#### Scenario: Extract tables with cell merging
|
|
- **WHEN** direct extraction encounters a table
|
|
- **THEN** the system SHALL use PyMuPDF find_tables() API
|
|
- **AND** extract cell content with correct rowspan/colspan
|
|
- **AND** preserve merged cell boundaries
|
|
- **AND** skip placeholder cells covered by merges
|
|
|
|
#### Scenario: Filter decoration images
|
|
- **WHEN** extracting images from PDF
|
|
- **THEN** the system SHALL filter images smaller than minimum area threshold
|
|
- **AND** exclude covering/redaction images
|
|
- **AND** preserve meaningful content images
|
|
|
|
#### Scenario: Preserve text styling with image handling
|
|
- **WHEN** direct extraction completes
|
|
- **THEN** the system SHALL convert PyMuPDF results to UnifiedDocument
|
|
- **AND** preserve text styling, fonts, and exact positioning
|
|
- **AND** extract tables with cell boundaries, content, and merge info
|
|
- **AND** include only meaningful images in output
|
|
|
|
### Requirement: Direct Track Background Image Rendering
|
|
|
|
The system SHALL render Direct Track PDF output using a full-page background image with an invisible text overlay to preserve visual fidelity while maintaining text extractability.
|
|
|
|
#### Scenario: Render Direct Track PDF with background image
|
|
- **WHEN** generating Layout PDF for a Direct Track document
|
|
- **THEN** the system SHALL render each source PDF page as a full-page background image at 2x resolution
|
|
- **AND** overlay invisible text elements using PDF Text Rendering Mode 3
|
|
- **AND** the invisible text SHALL be positioned at original coordinates for accurate selection
|
|
|
|
#### Scenario: Handle Office documents (PPT, DOC, XLS)
|
|
- **WHEN** processing an Office document converted to PDF
|
|
- **THEN** the system SHALL use the same background image + invisible text approach
|
|
- **AND** preserve all visual elements including vector graphics, gradients, and complex layouts
|
|
- **AND** the converted PDF in result directory SHALL be used as background source
|
|
|
|
#### Scenario: Handle native editable PDFs
|
|
- **WHEN** processing a native PDF through Direct Track
|
|
- **THEN** the system SHALL use the source PDF for background rendering
|
|
- **AND** apply the same invisible text overlay approach
|
|
- **AND** chart regions SHALL be excluded from the text layer
|
|
|
|
### Requirement: Chart Region Text Exclusion
|
|
|
|
The system SHALL exclude text elements within chart regions from the invisible text layer to prevent duplicate content and unnecessary translation.
|
|
|
|
#### Scenario: Detect chart regions
|
|
- **WHEN** classifying page elements for Direct Track
|
|
- **THEN** the system SHALL identify elements with type CHART
|
|
- **AND** add chart bounding boxes to regions_to_avoid list
|
|
|
|
#### Scenario: Exclude chart-internal text from invisible layer
|
|
- **WHEN** rendering invisible text layer
|
|
- **THEN** the system SHALL skip text elements whose bounding boxes overlap with chart regions
|
|
- **AND** chart axis labels, legends, and data labels SHALL NOT be in the invisible text layer
|
|
- **AND** these texts remain visible in the background image
|
|
|
|
#### Scenario: Chart text not available for translation
|
|
- **WHEN** extracting text for translation from a Direct Track document
|
|
- **THEN** chart-internal text SHALL NOT be included in translatable elements
|
|
- **AND** this is expected behavior as chart labels typically don't require translation
|
|
|