From bfc57ee9168c83c8369654a204639314bc88eacd Mon Sep 17 00:00:00 2001 From: jedarden Date: Wed, 27 May 2026 22:28:47 -0400 Subject: [PATCH] docs(pdftract-nf172): add coordinator verification note Add verification note for Phase 3.5 Inline Image skip coordinator. All 3 children closed, all acceptance criteria PASS. Co-Authored-By: Claude Opus 4.7 --- notes/pdftract-nf172.md | 64 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 notes/pdftract-nf172.md diff --git a/notes/pdftract-nf172.md b/notes/pdftract-nf172.md new file mode 100644 index 0000000..78e6125 --- /dev/null +++ b/notes/pdftract-nf172.md @@ -0,0 +1,64 @@ +# pdftract-nf172: Phase 3.5 Inline Image skip (coordinator) + +## Summary + +Coordinator bead for Phase 3.5: detect and skip BI/ID/EI inline image sequences in content streams. All 3 children have been completed and the inline image parsing functionality is fully implemented. + +## Children Completed + +All 3 children are CLOSED: +- **pdftract-1sxpa**: BI/ID inline image header parser - CLOSED (commit 4ac8479) +- **pdftract-1f0cj**: ID-to-EI raw-bytes scanner with whitespace-preceded EI detection - CLOSED +- **pdftract-axcri**: Inline image -> ImageXObject record in page image list - CLOSED + +## Acceptance Criteria Verification + +| Criterion | Status | Evidence | +|-----------|--------|----------| +| All 3 children closed | **PASS** | `bf show` confirms all 3 children are closed | +| Inline image followed by text operators parsed correctly | **PASS** | `parse_inline_image()` in render.rs advances lexer past EI; subsequent tokens parse normally | +| Embedded "EI" bytes not treated as terminator | **PASS** | Test `test_scan_inline_image_data_with_embedded_ei` passes - input `b"ABCDEI\nEI"` correctly returns `b"ABCDEI"` (inner EI not preceded by ws) | + +## Implementation Overview + +The inline image implementation works as follows: + +1. **Header parsing** (pdftract-1sxpa): `parse_inline_image_header()` parses BI...ID dictionary with shorthand key expansion +2. **Data scanning** (pdftract-1f0cj): `scan_inline_image_data()` byte-by-byte scan for whitespace-preceded EI +3. **ImageXObject recording** (pdftract-axcri): `collect_image_xobjects()` records both XObject and inline images with CTM-derived bbox + +## Test Results + +All 14 inline_image tests pass: +- `test_scan_inline_image_data_basic` - Basic BI...ID...EI parsing +- `test_scan_inline_image_data_with_embedded_ei` - EI in data not preceded by ws +- `test_scan_inline_image_data_empty` - Empty image +- `test_scan_inline_image_data_no_ei` - No terminator handling +- `test_scan_inline_image_data_various_whitespace` - All 6 ws bytes before EI +- `test_scan_inline_image_data_binary_content` - Binary data with 0x45/0x49 bytes +- `test_scan_inline_image_data_lexer_position` - Lexer advancement verification +- `test_parse_basic_header` - Basic header parsing +- `test_shorthand_expansion` - Shorthand key expansion +- `test_id_whitespace_validation` - ID whitespace requirement +- `test_parse_header_with_array_filter` - Array filter chains +- `test_parse_header_with_missing_value` - Malformed header recovery +- `test_inline_image_header_new` - Header construction +- `test_inline_image_header_has_required_fields` - Field presence + +## Integration with Content Stream Parser + +The `collect_image_xobjects()` function in `render.rs` integrates inline image parsing into the content stream interpreter: +- BI keyword triggers `parse_inline_image()` which consumes the entire BI/ID/EI sequence +- Lexer is positioned after EI, allowing subsequent text operators to parse correctly +- ImageXObject entries are added to page image list for Phase 4.4 figure detection + +## Known Limitations + +Per the plan's "Critical considerations": +- The whitespace-EI heuristic may terminate early if compressed image data contains `EI` (rare) +- A more robust solution would compute expected byte length from width/height/bpc/colorspace (deferred to v0.2.0+) + +## References + +- Plan section: Phase 3.5 Inline Images (lines 1592-1600) +- ISO 32000-1 sec 8.9.7