Phase 7.4.5 implementation: Wire combined Vec<(String, FormFieldValue)> from
combiner into document-level /form_fields JSON output with tagged union schema.
- Add FormFieldJson, FormFieldTypeJson, FormFieldValueJson, ChoiceValueJson to schema
- Add form_fields: Vec<FormFieldJson> to ExtractionResult (always emitted, empty when none)
- Implement acro_field_to_value() converter for Phase 7.4.2 type-specific extraction
- Wire form field extraction in extract_pdf(): walk AcroForm, extract XFA, combine with XFA-wins
- Add convert_form_field_to_json() helper for FormFieldValue → FormFieldJson conversion
- Update docs/schema/v1.0/pdftract.schema.json with form_fields $defs and required field
- Add form_fields_to_markdown() to markdown module for Form Fields footer table
Schema shape: /form_fields is array of {name, type, value, default?, page_index?, rect?,
required, read_only, multiline?, max_length?, options?, multi_select?, selected?,
state_name?, pushbutton?, radio?}. Type field is tagged enum: "text", "button", "choice",
"signature". Value field varies by type (string|boolean|string|array|uint|null).
Closes: pdftract-5qca
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Add OcrFallback variant to SpanSource enum for fallback spans
- Add page_seg_mode field to TessOpts for PSM_SPARSE_TEXT support
- Add ASSISTED_OCR_KEEP_THRESH (0.7) and ASSISTED_OCR_FALLBACK_THRESH (0.3) constants
- Implement apply_region_level_confidence_policy() for region-level decision making
- Group words by baseline proximity (12pt tolerance) for region computation
- Add TODO for Phase 6.1 confidence_source enum to include "ocr-fallback"
Closes: pdftract-29gu
Implement char-weighted median aggregation of per-span readability
scores into a page-level score stored in extraction_quality.readability.
Algorithm:
- Collect (score, char_count) pairs from spans
- Sort by score ascending
- Walk sorted list accumulating character counts
- Return score at half-total-char position
Acceptance criteria:
- Single span: returns its score
- Multiple spans: char-weighted median (longer spans count more)
- Empty page: returns 0.0
- All-perfect: returns 1.0
Closes: pdftract-oh30a
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Implement the Receipt struct and lite-mode JSON serialization for
visual citation receipts. This provides cryptographic proof of
provenance for extracted text.
Changes:
- Add Receipt struct with 6 fields (pdf_fingerprint, page_index,
bbox, content_hash, extraction_version, svg_clip)
- Implement Receipt::lite() constructor with NFC normalization
- Integrate Receipt into SpanJson and BlockJson schemas
- Add unicode-normalization and serde_json dependencies
Acceptance criteria:
- Receipt::lite() produces valid receipts with svg_clip=None
- Lite mode JSON omits svg_clip key via skip_serializing_if
- Content hash uses NFC normalization for cross-platform stability
- Receipt wired into SpanJson and BlockJson types
Note: 100 receipts aggregate size is ~27 KB (not 15 KB as planned).
The 15 KB target is not achievable with required field sizes.
Refs: pdftract-5zm86, Phase 6.8 Visual Citation Receipts (lines 2351-2417)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
