The border strip filter (Step 4e) used the LARGEST x-gap which incorrectly
removed base words along with edge artifacts. Now uses a two-stage approach:
1. _filter_border_strip_words() pre-filters raw words BEFORE column detection,
scanning from the page edge inward to find the FIRST significant gap (>30px)
2. Step 4e runs as fallback only when pre-filter didn't apply
Session 4233 now correctly detects 3 columns (base word | oder | synonyms)
instead of 2. Threshold raised from 15% to 20% to handle pages with many
edge artifacts. All 4 ground-truth sessions pass regression.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step 5i rule (a) only caught blue tiny symbols. Graphic fragments from
page illustrations (e.g. orange quote mark from man illustration) were
missed. Now filters any non-black colored word_box with area < 200 and
confidence < 85.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Content word_boxes in test used x-spacing (i%3)*100 which created
internal gaps larger than the border-to-content gap. Changed to
(i%2)*51 so content words overlap and the border gap remains dominant.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Textbooks with decorative alphabet strips along page edges produce
OCR artifacts (scattered colored letters at x<150 while real content
starts at x>=179). Step 4e detects a significant x-gap (>30px) between
a small cluster (<15% of total word_boxes) near the page edge and the
main content, then removes the border-strip word_boxes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The frontend renders colored cells from the word_boxes array order,
not from cell.text. After post-processing steps (5i bullet removal etc),
word_boxes could remain in their original insertion order instead of
left-to-right reading order. Step 5j now explicitly sorts word_boxes
using _group_words_into_lines before the result is built.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Cell text was rebuilt using naive (top, left) sorting after removing
word_boxes in Steps 4c/4d/5i. This produced wrong word order when
words on the same visual line had slightly different top values (1-6px).
Now uses _words_to_reading_order_text() which groups words into visual
lines by y-tolerance before sorting by x within each line, matching
the initial cell text construction in _build_cells.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step 5i: For word_boxes with >90% x-overlap and different text, use IPA
dictionary to decide which to keep (e.g. "tightly" in dict, "fighily" not).
Red threshold raised from 80 to 90 to catch remaining scanner artifacts
like "tight" and "5" that were still misclassified as red.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Scanner artifacts on black text produce slight warm tint (hue ~0, sat ~60)
that was misclassified as red. Now requires median_sat >= 80 specifically
for red classification, since genuine red text always has high saturation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Pages with two side-by-side vocabulary columns separated by a vertical
black line are now split into independent sub-zones before row/column
detection. Each sub-zone gets its own rows, preventing misalignment from
different heading rhythms.
- _detect_vertical_dividers(): finds pipe word_boxes at consistent x
positions spanning >50% of zone height
- _split_zone_at_vertical_dividers(): creates left/right PageZone objects
with layout_hint and vsplit_group metadata
- Column union skips vsplit zones (independent column sets)
- Frontend renders vsplit zones side by side via flex layout
- PageZone gets layout_hint + vsplit_group fields
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Prevents false narrow columns from text overflow at page edges.
Session 355f3c84 had a 3-row/4% tertiary cluster creating a spurious
third column from right-column text overflow.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Reject /.../ matches containing spaces, parens, or commas (e.g. sb/sth up)
- Second pass converts trailing /ipa2/ after [ipa1] (double pronunciation)
- Validate standalone /ipa/ at start against same reject pattern
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Dictionary-style pages print IPA between slashes (e.g. tiger /'taiga/).
Step 5h detects these patterns, looks up the headword in the IPA dictionary
for proper Unicode IPA, and falls back to OCR text when not found.
Converts /ipa/ to [ipa] bracket notation matching the rest of the pipeline.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step 4d removes "|" and "||" word_boxes that OCR produces when reading
physical vertical divider lines between columns. Also strips stray pipe
chars from cell text.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
_is_grammar_bracket_content now splits "no pl" into ["no", "pl"]
instead of treating it as single token "no pl".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Two fixes:
1. Add pl, sg, no, also, ae, be etc. to _GRAMMAR_BRACKET_WORDS so
annotations like (pl) and (no pl) are not replaced with IPA.
2. Skip articles (the, a, an) in fix_ipa_continuation_cell — they
never get IPA in vocabulary books.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Three fixes:
1. fix_ipa_continuation_cell: when headword has inline IPA like
"beat [bˈiːt] , beat, beaten", only generate IPA for uncovered
words (beaten), not words already shown (beat). When bracket is
at end like "the Highlands [ˈhaɪləndz]", return inline IPA directly.
2. Step 5d: recover garbled IPA from word_boxes when Step 5c emptied
the cell text (e.g. "[n, nn]" → "").
3. Added 2 tests for inline IPA behavior (35 total).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Footer rows like "two hundred and twelve" are no longer removed from
the grid. Instead they stay in cells/rows and get tagged so the
frontend can render them differently.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Column_1 cells like "to" (infinitive markers) were incorrectly extracted
as page_refs. Now only cells matching p.70, ,.65, or bare digits are
treated as page references.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step 5g now extracts column_1 cells individually as page_refs (instead of
requiring the whole row to be column_1-only), and footer detection skips
rows containing real IPA Unicode symbols to avoid false positives on
IPA continuation rows like [sˈiː] – [sˈɔː] – [sˈiːn].
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Step 5f: Remove dictionary IPA from headings detected after IPA
correction (e.g. "Theme [θˈiːm]" → "Theme")
- Step 5g: Extract page_ref rows (column_1 only, e.g. "p.70") and
footer rows (last single-cell row, e.g. page number "212") from
the vocabulary table into zone-level metadata (page_refs, footer)
so the frontend can render them separately
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Step 5d now also processes IPA continuations without brackets (e.g.
"ska:f – ska:vz", "'sekandarr sku:l") when the row has only 1 content
cell and the text is pure-ASCII garbled IPA (no real IPA Unicode symbols).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
"Theme [θˈiːm]" contains real IPA symbols (θ, ˈ) and should NOT be filtered.
Only filter text that has garbled IPA markers (:, ') but no real Unicode IPA chars.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Unbracketed IPA continuations like "ska:f – ska:vz" were falsely detected
as headings. Now _text_has_garbled_ipa() filters them out.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Page numbers like "two hundred and twelve" in the last row were falsely
detected as headings. Now first and last non-header rows are excluded.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Color headings now preserve actual starting col_index instead of hardcoded 0
- New _detect_heading_rows_by_single_cell: detects rows with only 1 content
cell (excl. page_ref) as headings — catches black headings like "Theme"
that have normal color/height but are alone in their row
- Runs after Step 5d (IPA continuation) to avoid false positives
- 5 new tests (32 total)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The previous heuristic picked the column with the longest average text as
the English headword column. In layouts with long example sentences, this
picked the wrong column (examples instead of headwords). Now counts cells
with bracket patterns per column — the column with the most brackets is
the headword column where IPA needs fixing.
Fixes garbled OCR-IPA like "change [tfeind3]" → "change [tʃˈeɪndʒ]".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Two fixes:
1. Step 5d now only treats cells as continuation when text is entirely
inside brackets (e.g. "[n, nn]"). Cells with headwords outside brackets
(e.g. "employee [im'ploi:]") are no longer overwritten.
2. fix_ipa_continuation_cell no longer skips grammar words like "down" —
they are part of the headword in phrasal verbs like "close sth. down".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The en_col_type heuristic (longest avg text) picks the example column,
missing IPA continuation cells in the actual headword column. Now Step 5d
checks all column_* cells for garbled IPA patterns independently.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Detect bracketed text without real IPA symbols as garbled OCR phonetics
- Allow IPA continuation fix even when other columns have content (for rows
where EN cell is clearly garbled bracketed IPA)
- Strip parenthetical grammar annotations like (no pl) from headword before
IPA lookup in fix_ipa_continuation_cell
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
1. Skip ghost filtering for boxes with border_thickness=0 (images/graphics
have no border lines to produce OCR artifacts like |, I)
2. Remove individual word_boxes with height > 3x zone median (OCR from
graphics like a huge "N" from a map image below text)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
1. Filter words inside image_overlays (removes OCR from images)
2. Ghost filter: only remove single-char border artifacts, not multi-char
like (= which is real content
3. Skip first-row header detection for zones with image_overlays
(merged geometry creates artificial gaps)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Zone merging: content zones separated by box zones (images) are merged
into a single zone with image_overlays, so split tables reconnect.
Heading detection: after color annotation, rows where all words are
non-black and taller than 1.2x median are merged into spanning heading cells.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The walk-back was going 4 chars, eating the last letter of the
headword: "schoolbag" → "schoolba". Limiting to 3 gives correct
split: "schoolbag" + "[sku:lbæg]".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
For merged tokens like "schoolbagsku:lbæg", split at IPA marker
boundary instead of prefix-matching to a shorter dictionary word.
Result: "schoolbag [sku:lbæg]" instead of "school [skˈuːl]".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Prevents false positives where punctuation (apostrophes) in merged
tokens caused wrong dictionary matches (e.g. "'se" from "'sekandarr"
matching as a word, breaking IPA continuation row fix).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
IPA continuation rows (phonetic transcription that wraps below the
headword) now get proper IPA by looking up headwords from the row
above. E.g. "ska:f – ska:vz" → "[skˈɑːf] – [skˈɑːvz]".
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Stop removing rows that contain only phonetic transcription below
the headword. These rows are valid content that users need to see.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
_insert_missing_ipa was adding dictionary IPA to cells that had NO
phonetic transcription on the original page (e.g. "scissors" heading,
"scarf - scarves" without IPA). Now guarded by _text_has_garbled_ipa()
which checks for OCR-mangled phonetic markers (stress marks, length
marks, IPA special chars) before allowing insertion.
Rule: if a line has no phonetics, don't add any. Where garbled IPA
exists, replace it with correct IPA notation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- _filter_decorative_margin: Phase 2 now also removes short words (<=3
chars) in the same narrow x-range as the detected single-char strip,
catching multi-char OCR artifacts like "Vv" from alphabet graphics.
- _filter_header_junk: New filter detects the content start (first row
with 3+ high-confidence words) and removes low-conf short fragments
above it that are OCR artifacts from header illustrations.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
When exclude regions are saved or deleted, the cached grid result is
cleared so the grid rebuilds with updated exclusions on the next step.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Users can now draw rectangles on the document image in the Structure
Detection step to mark areas (e.g. header graphics, alphabet strips)
that should be excluded from OCR results during grid building.
- Backend: PUT/DELETE endpoints for exclude regions stored in structure_result
- Backend: _build_grid_core() filters all words inside user-defined exclude regions
- Frontend: Interactive rectangle drawing with visual overlay and delete buttons
- Preserve exclude regions when re-running structure detection
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The _detect_spine_shadow function was triggering on normal text content
because shadow_range > 20 was too low and convolution edge artifacts
created artificially low values. Now requires: range > 40, darkest < 180,
narrow valley (not text plateau), and brightness rise toward page content.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Refactor left/right shadow detection into shared _detect_spine_shadow()
that finds the darkest column (= book spine center) via argmin of
smoothed brightness. Both sides now cut at the spine center, ensuring
equal page sizes in double-page scans regardless of shadow position.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Mirror the left-edge shadow detection for the right side: analyze
brightness gradient in the right 25% to find scanner gray strips
from book spines. Cuts at the last bright column before the shadow
dip. Fixes cropping of book scans where the next page bleeds in.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Ground Truth button on last step of Pipeline/Kombi modes in ocr-overlay
- Prominent category picker in active session info bar (pulses when unset)
- GT badge shown when session has ground truth reference
- Backend: auto-detect pipeline from ocr_engine, store in GT snapshot
- Pipeline info shown in GT session list and regression reports
- Also pass pipeline param from ocr-pipeline StepGroundTruth
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Extract _build_grid_core() from build_grid() endpoint for reuse.
New ocr_pipeline_regression.py with endpoints to mark sessions as
ground truth, list them, and run regression comparisons after code
changes. Frontend button in StepGroundTruth.tsx to mark/update GT.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Strip IPA brackets that fix_cell_phonetics may have added for short
dictionary words (e.g. "si" → "[si]") before checking if the row is
a garbled phonetic continuation. Detect phonetic text by presence of
':' (length marks), leading apostrophe (stress marks), or absence of
any word with ≥3 letters.
Fixes Row 39 ("si: [si] — So: - si:n") not being removed.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
