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breakpilot-lehrer/klausur-service/backend/grid_editor_api.py
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Fix unbracketed IPA continuations: detect garbled IPA in single-cell rows
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>
2026-03-20 08:30:44 +01:00

2021 lines
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"""
Grid Editor API — builds a structured, zone-aware grid from Kombi OCR results.
Takes the merged word positions from paddle-kombi / rapid-kombi and:
1. Detects bordered boxes on the image (cv_box_detect)
2. Splits the page into zones (content + box regions)
3. Clusters words into columns and rows per zone
4. Returns a hierarchical StructuredGrid for the frontend Excel-like editor
Lizenz: Apache 2.0 (kommerziell nutzbar)
DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
"""
import logging
import re
import time
from typing import Any, Dict, List, Optional
import cv2
import numpy as np
from fastapi import APIRouter, HTTPException, Request
from cv_box_detect import detect_boxes, split_page_into_zones
from cv_vocab_types import PageZone
from cv_color_detect import detect_word_colors, recover_colored_text
from cv_ocr_engines import fix_cell_phonetics, fix_ipa_continuation_cell, _text_has_garbled_ipa
from cv_words_first import _cluster_rows, _build_cells
from ocr_pipeline_session_store import (
get_session_db,
get_session_image,
update_session_db,
)
logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api/v1/ocr-pipeline", tags=["grid-editor"])
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
def _cluster_columns_by_alignment(
words: List[Dict],
zone_w: int,
rows: List[Dict],
) -> List[Dict[str, Any]]:
"""Detect columns by clustering left-edge alignment across rows.
Hybrid approach:
1. Group words by row, find "group start" positions within each row
(words preceded by a large gap or first word in row)
2. Cluster group-start left-edges by X-proximity across rows
3. Filter by row coverage (how many rows have a group start here)
4. Merge nearby clusters
5. Build column boundaries
This filters out mid-phrase word positions (e.g. IPA transcriptions,
second words in multi-word entries) by only considering positions
where a new word group begins within a row.
"""
if not words or not rows:
return []
total_rows = len(rows)
if total_rows == 0:
return []
# --- Group words by row ---
row_words: Dict[int, List[Dict]] = {}
for w in words:
y_center = w["top"] + w["height"] / 2
best = min(rows, key=lambda r: abs(r["y_center"] - y_center))
row_words.setdefault(best["index"], []).append(w)
# --- Compute adaptive gap threshold for group-start detection ---
all_gaps: List[float] = []
for ri, rw_list in row_words.items():
sorted_rw = sorted(rw_list, key=lambda w: w["left"])
for i in range(len(sorted_rw) - 1):
right = sorted_rw[i]["left"] + sorted_rw[i]["width"]
gap = sorted_rw[i + 1]["left"] - right
if gap > 0:
all_gaps.append(gap)
if all_gaps:
sorted_gaps = sorted(all_gaps)
median_gap = sorted_gaps[len(sorted_gaps) // 2]
heights = [w["height"] for w in words if w.get("height", 0) > 0]
median_h = sorted(heights)[len(heights) // 2] if heights else 25
# Column boundary: gap > 3× median gap or > 1.5× median word height
gap_threshold = max(median_gap * 3, median_h * 1.5, 30)
else:
gap_threshold = 50
# --- Find group-start positions (left-edges that begin a new column) ---
start_positions: List[tuple] = [] # (left_edge, row_index)
for ri, rw_list in row_words.items():
sorted_rw = sorted(rw_list, key=lambda w: w["left"])
# First word in row is always a group start
start_positions.append((sorted_rw[0]["left"], ri))
for i in range(1, len(sorted_rw)):
right_prev = sorted_rw[i - 1]["left"] + sorted_rw[i - 1]["width"]
gap = sorted_rw[i]["left"] - right_prev
if gap >= gap_threshold:
start_positions.append((sorted_rw[i]["left"], ri))
start_positions.sort(key=lambda x: x[0])
logger.info(
"alignment columns: %d group-start positions from %d words "
"(gap_threshold=%.0f, %d rows)",
len(start_positions), len(words), gap_threshold, total_rows,
)
if not start_positions:
x_min = min(w["left"] for w in words)
x_max = max(w["left"] + w["width"] for w in words)
return [{"index": 0, "type": "column_text", "x_min": x_min, "x_max": x_max}]
# --- Cluster group-start positions by X-proximity ---
tolerance = max(10, int(zone_w * 0.01))
clusters: List[Dict[str, Any]] = []
cur_edges = [start_positions[0][0]]
cur_rows = {start_positions[0][1]}
for left, row_idx in start_positions[1:]:
if left - cur_edges[-1] <= tolerance:
cur_edges.append(left)
cur_rows.add(row_idx)
else:
clusters.append({
"mean_x": int(sum(cur_edges) / len(cur_edges)),
"min_edge": min(cur_edges),
"max_edge": max(cur_edges),
"count": len(cur_edges),
"distinct_rows": len(cur_rows),
"row_coverage": len(cur_rows) / total_rows,
})
cur_edges = [left]
cur_rows = {row_idx}
clusters.append({
"mean_x": int(sum(cur_edges) / len(cur_edges)),
"min_edge": min(cur_edges),
"max_edge": max(cur_edges),
"count": len(cur_edges),
"distinct_rows": len(cur_rows),
"row_coverage": len(cur_rows) / total_rows,
})
# --- Filter by row coverage ---
# These thresholds must be high enough to avoid false columns in flowing
# text (random inter-word gaps) while still detecting real columns in
# vocabulary worksheets (which typically have >80% row coverage).
MIN_COVERAGE_PRIMARY = 0.35
MIN_COVERAGE_SECONDARY = 0.20
MIN_WORDS_SECONDARY = 4
MIN_DISTINCT_ROWS = 3
# Content boundary for left-margin detection
content_x_min = min(w["left"] for w in words)
content_x_max = max(w["left"] + w["width"] for w in words)
content_span = content_x_max - content_x_min
primary = [
c for c in clusters
if c["row_coverage"] >= MIN_COVERAGE_PRIMARY
and c["distinct_rows"] >= MIN_DISTINCT_ROWS
]
primary_ids = {id(c) for c in primary}
secondary = [
c for c in clusters
if id(c) not in primary_ids
and c["row_coverage"] >= MIN_COVERAGE_SECONDARY
and c["count"] >= MIN_WORDS_SECONDARY
and c["distinct_rows"] >= MIN_DISTINCT_ROWS
]
# Tertiary: narrow left-margin columns (page refs, markers) that have
# too few rows for secondary but are clearly left-aligned and separated
# from the main content. These appear at the far left or far right and
# have a large gap to the nearest significant cluster.
used_ids = {id(c) for c in primary} | {id(c) for c in secondary}
sig_xs = [c["mean_x"] for c in primary + secondary]
tertiary = []
for c in clusters:
if id(c) in used_ids or c["distinct_rows"] < MIN_DISTINCT_ROWS:
continue
# Must be near left or right content margin (within 15%)
rel_pos = (c["mean_x"] - content_x_min) / content_span if content_span else 0.5
if not (rel_pos < 0.15 or rel_pos > 0.85):
continue
# Must have significant gap to nearest significant cluster
if sig_xs:
min_dist = min(abs(c["mean_x"] - sx) for sx in sig_xs)
if min_dist < max(30, content_span * 0.02):
continue
tertiary.append(c)
if tertiary:
for c in tertiary:
logger.info(
" tertiary (margin) cluster: x=%d (range %d-%d), %d words, %d rows (%.0f%%)",
c["mean_x"], c["min_edge"], c["max_edge"],
c["count"], c["distinct_rows"], c["row_coverage"] * 100,
)
significant = sorted(primary + secondary + tertiary, key=lambda c: c["mean_x"])
for c in significant:
logger.info(
" significant cluster: x=%d (range %d-%d), %d words, %d rows (%.0f%%)",
c["mean_x"], c["min_edge"], c["max_edge"],
c["count"], c["distinct_rows"], c["row_coverage"] * 100,
)
logger.info(
"alignment columns: %d clusters, %d primary, %d secondary → %d significant",
len(clusters), len(primary), len(secondary), len(significant),
)
if not significant:
# Fallback: single column covering all content
x_min = min(w["left"] for w in words)
x_max = max(w["left"] + w["width"] for w in words)
return [{"index": 0, "type": "column_text", "x_min": x_min, "x_max": x_max}]
# --- Merge nearby clusters ---
merge_distance = max(25, int(zone_w * 0.03))
merged = [significant[0].copy()]
for s in significant[1:]:
if s["mean_x"] - merged[-1]["mean_x"] < merge_distance:
prev = merged[-1]
total = prev["count"] + s["count"]
prev["mean_x"] = (
prev["mean_x"] * prev["count"] + s["mean_x"] * s["count"]
) // total
prev["count"] = total
prev["min_edge"] = min(prev["min_edge"], s["min_edge"])
prev["max_edge"] = max(prev["max_edge"], s["max_edge"])
prev["distinct_rows"] = max(prev["distinct_rows"], s["distinct_rows"])
else:
merged.append(s.copy())
logger.info(
"alignment columns: %d after merge (distance=%d)",
len(merged), merge_distance,
)
# --- Build column boundaries ---
margin = max(5, int(zone_w * 0.005))
content_x_min = min(w["left"] for w in words)
content_x_max = max(w["left"] + w["width"] for w in words)
columns: List[Dict[str, Any]] = []
for i, cluster in enumerate(merged):
x_min = max(content_x_min, cluster["min_edge"] - margin)
if i + 1 < len(merged):
x_max = merged[i + 1]["min_edge"] - margin
else:
x_max = content_x_max
columns.append({
"index": i,
"type": f"column_{i + 1}" if len(merged) > 1 else "column_text",
"x_min": x_min,
"x_max": x_max,
})
return columns
# Characters that are typically OCR artefacts from box border lines.
# Intentionally excludes ! (red markers) and . , ; (real punctuation).
_GRID_GHOST_CHARS = set("|1lI[](){}/\\-—_~=+")
def _filter_border_ghosts(
words: List[Dict],
boxes: List,
) -> tuple:
"""Remove words sitting on box borders that are OCR artefacts.
Returns (filtered_words, removed_count).
"""
if not boxes or not words:
return words, 0
# Build border bands from detected boxes
x_bands: List[tuple] = []
y_bands: List[tuple] = []
for b in boxes:
bt = (
b.border_thickness
if hasattr(b, "border_thickness")
else b.get("border_thickness", 3)
)
# Skip borderless boxes (images/graphics) — no border line to produce ghosts
if bt == 0:
continue
bx = b.x if hasattr(b, "x") else b.get("x", 0)
by = b.y if hasattr(b, "y") else b.get("y", 0)
bw = b.width if hasattr(b, "width") else b.get("w", b.get("width", 0))
bh = b.height if hasattr(b, "height") else b.get("h", b.get("height", 0))
margin = max(bt * 2, 10) + 6
x_bands.append((bx - margin, bx + margin))
x_bands.append((bx + bw - margin, bx + bw + margin))
y_bands.append((by - margin, by + margin))
y_bands.append((by + bh - margin, by + bh + margin))
def _is_ghost(w: Dict) -> bool:
text = (w.get("text") or "").strip()
if not text:
return False
# Check if any word edge (not just center) touches a border band
w_left = w["left"]
w_right = w["left"] + w["width"]
w_top = w["top"]
w_bottom = w["top"] + w["height"]
on_border = (
any(lo <= w_left <= hi or lo <= w_right <= hi for lo, hi in x_bands)
or any(lo <= w_top <= hi or lo <= w_bottom <= hi for lo, hi in y_bands)
)
if not on_border:
return False
if len(text) == 1 and text in _GRID_GHOST_CHARS:
return True
return False
filtered = [w for w in words if not _is_ghost(w)]
return filtered, len(words) - len(filtered)
_MARKER_CHARS = set("•*·-–—|~=+#>→►▸▪◆○●□■✓✗✔✘")
def _merge_inline_marker_columns(
columns: List[Dict],
words: List[Dict],
) -> List[Dict]:
"""Merge narrow marker columns (bullets, numbering) into adjacent text.
Bullet points (•, *, -) and numbering (1., 2.) create narrow columns
at the left edge of a zone. These are inline markers that indent text,
not real separate columns. Merge them with their right neighbour.
Does NOT merge columns containing alphabetic words like "to", "in",
"der", "die", "das" — those are legitimate content columns.
"""
if len(columns) < 2:
return columns
merged: List[Dict] = []
skip: set = set()
for i, col in enumerate(columns):
if i in skip:
continue
# Find words in this column
col_words = [
w for w in words
if col["x_min"] <= w["left"] + w["width"] / 2 < col["x_max"]
]
col_width = col["x_max"] - col["x_min"]
# Narrow column with mostly short words → MIGHT be inline markers
if col_words and col_width < 80:
avg_len = sum(len(w.get("text", "")) for w in col_words) / len(col_words)
if avg_len <= 2 and i + 1 < len(columns):
# Check if words are actual markers (symbols/numbers) vs
# real alphabetic words like "to", "in", "der", "die"
texts = [(w.get("text") or "").strip() for w in col_words]
alpha_count = sum(
1 for t in texts
if t and t[0].isalpha() and t not in _MARKER_CHARS
)
alpha_ratio = alpha_count / len(texts) if texts else 0
# If ≥50% of words are alphabetic, this is a real column
if alpha_ratio >= 0.5:
logger.info(
" kept narrow column %d (w=%d, avg_len=%.1f, "
"alpha=%.0f%%) — contains real words",
i, col_width, avg_len, alpha_ratio * 100,
)
else:
# Merge into next column
next_col = columns[i + 1].copy()
next_col["x_min"] = col["x_min"]
merged.append(next_col)
skip.add(i + 1)
logger.info(
" merged inline marker column %d (w=%d, avg_len=%.1f) "
"into column %d",
i, col_width, avg_len, i + 1,
)
continue
merged.append(col)
# Re-index
for i, col in enumerate(merged):
col["index"] = i
col["type"] = f"column_{i + 1}" if len(merged) > 1 else "column_text"
return merged
def _flatten_word_boxes(cells: List[Dict]) -> List[Dict]:
"""Extract all word_boxes from cells into a flat list of word dicts."""
words: List[Dict] = []
for cell in cells:
for wb in cell.get("word_boxes") or []:
if wb.get("text", "").strip():
words.append({
"text": wb["text"],
"left": wb["left"],
"top": wb["top"],
"width": wb["width"],
"height": wb["height"],
"conf": wb.get("conf", 0),
})
return words
def _words_in_zone(
words: List[Dict],
zone_y: int,
zone_h: int,
zone_x: int,
zone_w: int,
) -> List[Dict]:
"""Filter words whose Y-center falls within a zone's bounds."""
zone_y_end = zone_y + zone_h
zone_x_end = zone_x + zone_w
result = []
for w in words:
cy = w["top"] + w["height"] / 2
cx = w["left"] + w["width"] / 2
if zone_y <= cy <= zone_y_end and zone_x <= cx <= zone_x_end:
result.append(w)
return result
def _merge_content_zones_across_boxes(
zones: List,
content_x: int,
content_w: int,
) -> List:
"""Merge content zones separated by box zones into single zones.
Box zones become image_overlays on the merged content zone.
Pattern: [content, box*, content] → [merged_content with overlay]
Box zones NOT between two content zones stay as standalone zones.
"""
if len(zones) < 3:
return zones
# Group consecutive runs of [content, box+, content]
result: List = []
i = 0
while i < len(zones):
z = zones[i]
if z.zone_type != "content":
result.append(z)
i += 1
continue
# Start of a potential merge group: content zone
group_contents = [z]
group_boxes = []
j = i + 1
# Absorb [box, content] pairs — only absorb a box if it's
# confirmed to be followed by another content zone.
while j < len(zones):
if (zones[j].zone_type == "box"
and j + 1 < len(zones)
and zones[j + 1].zone_type == "content"):
group_boxes.append(zones[j])
group_contents.append(zones[j + 1])
j += 2
else:
break
if len(group_contents) >= 2 and group_boxes:
# Merge: create one large content zone spanning all
y_min = min(c.y for c in group_contents)
y_max = max(c.y + c.height for c in group_contents)
overlays = []
for bz in group_boxes:
overlay = {
"y": bz.y,
"height": bz.height,
"x": bz.x,
"width": bz.width,
}
if bz.box:
overlay["box"] = {
"x": bz.box.x,
"y": bz.box.y,
"width": bz.box.width,
"height": bz.box.height,
"confidence": bz.box.confidence,
"border_thickness": bz.box.border_thickness,
}
overlays.append(overlay)
merged = PageZone(
index=0, # re-indexed below
zone_type="content",
y=y_min,
height=y_max - y_min,
x=content_x,
width=content_w,
image_overlays=overlays,
)
result.append(merged)
i = j
else:
# No merge possible — emit just the content zone
result.append(z)
i += 1
# Re-index zones
for idx, z in enumerate(result):
z.index = idx
logger.info(
"zone-merge: %d zones → %d zones after merging across boxes",
len(zones), len(result),
)
return result
def _detect_heading_rows_by_color(zones_data: List[Dict], img_w: int, img_h: int) -> int:
"""Detect heading rows by color + height after color annotation.
A row is a heading if:
1. ALL word_boxes have color_name != 'black' (typically 'blue')
2. Mean word height > 1.2x median height of all words in the zone
Detected heading rows are merged into a single spanning cell.
Returns count of headings detected.
"""
heading_count = 0
for z in zones_data:
cells = z.get("cells", [])
rows = z.get("rows", [])
columns = z.get("columns", [])
if not cells or not rows or len(columns) < 2:
continue
# Compute median word height across the zone
all_heights = []
for cell in cells:
for wb in cell.get("word_boxes") or []:
h = wb.get("height", 0)
if h > 0:
all_heights.append(h)
if not all_heights:
continue
all_heights_sorted = sorted(all_heights)
median_h = all_heights_sorted[len(all_heights_sorted) // 2]
heading_row_indices = []
for row in rows:
if row.get("is_header"):
continue # already detected as header
ri = row["index"]
row_cells = [c for c in cells if c.get("row_index") == ri]
row_wbs = [
wb for cell in row_cells
for wb in cell.get("word_boxes") or []
]
if not row_wbs:
continue
# Condition 1: ALL words are non-black
all_colored = all(
wb.get("color_name", "black") != "black"
for wb in row_wbs
)
if not all_colored:
continue
# Condition 2: mean height > 1.2x median
mean_h = sum(wb.get("height", 0) for wb in row_wbs) / len(row_wbs)
if mean_h <= median_h * 1.2:
continue
heading_row_indices.append(ri)
# Merge heading cells into spanning cells
for hri in heading_row_indices:
header_cells = [c for c in cells if c.get("row_index") == hri]
if len(header_cells) <= 1:
# Single cell — just mark it as heading
if header_cells:
header_cells[0]["col_type"] = "heading"
heading_count += 1
# Mark row as header
for row in rows:
if row["index"] == hri:
row["is_header"] = True
continue
# Collect all word_boxes and text from all columns
all_wb = []
all_text_parts = []
for hc in sorted(header_cells, key=lambda c: c["col_index"]):
all_wb.extend(hc.get("word_boxes", []))
if hc.get("text", "").strip():
all_text_parts.append(hc["text"].strip())
# Remove all cells for this row, replace with one spanning cell
z["cells"] = [c for c in z["cells"] if c.get("row_index") != hri]
if all_wb:
x_min = min(wb["left"] for wb in all_wb)
y_min = min(wb["top"] for wb in all_wb)
x_max = max(wb["left"] + wb["width"] for wb in all_wb)
y_max = max(wb["top"] + wb["height"] for wb in all_wb)
# Use the actual starting col_index from the first cell
first_col = min(hc["col_index"] for hc in header_cells)
zone_idx = z.get("zone_index", 0)
z["cells"].append({
"cell_id": f"Z{zone_idx}_R{hri:02d}_C{first_col}",
"zone_index": zone_idx,
"row_index": hri,
"col_index": first_col,
"col_type": "heading",
"text": " ".join(all_text_parts),
"confidence": 0.0,
"bbox_px": {"x": x_min, "y": y_min,
"w": x_max - x_min, "h": y_max - y_min},
"bbox_pct": {
"x": round(x_min / img_w * 100, 2) if img_w else 0,
"y": round(y_min / img_h * 100, 2) if img_h else 0,
"w": round((x_max - x_min) / img_w * 100, 2) if img_w else 0,
"h": round((y_max - y_min) / img_h * 100, 2) if img_h else 0,
},
"word_boxes": all_wb,
"ocr_engine": "words_first",
"is_bold": True,
})
# Mark row as header
for row in rows:
if row["index"] == hri:
row["is_header"] = True
heading_count += 1
return heading_count
def _detect_heading_rows_by_single_cell(
zones_data: List[Dict], img_w: int, img_h: int,
) -> int:
"""Detect heading rows that have only a single content cell.
Black headings like "Theme" have normal color and height, so they are
missed by ``_detect_heading_rows_by_color``. The distinguishing signal
is that they occupy only one column while normal vocabulary rows fill
at least 2-3 columns.
A row qualifies as a heading if:
1. It is not already marked as a header/heading.
2. It has exactly ONE cell whose col_type starts with ``column_``
(excluding column_1 / page_ref which only carries page numbers).
3. That single cell is NOT in the last column (continuation/example
lines like "2. Veränderung, Wechsel" often sit alone in column_4).
4. The text does not start with ``[`` (IPA continuation).
5. The zone has ≥3 columns and ≥5 rows (avoids false positives in
tiny zones).
6. The majority of rows in the zone have ≥2 content cells (ensures
we are in a multi-column vocab layout).
"""
heading_count = 0
for z in zones_data:
cells = z.get("cells", [])
rows = z.get("rows", [])
columns = z.get("columns", [])
if len(columns) < 3 or len(rows) < 5:
continue
# Determine the last col_index (example/sentence column)
col_indices = sorted(set(c.get("col_index", 0) for c in cells))
if not col_indices:
continue
last_col = col_indices[-1]
# Count content cells per row (column_* but not column_1/page_ref)
row_content_counts: Dict[int, int] = {}
for cell in cells:
ct = cell.get("col_type", "")
if ct.startswith("column_") and ct != "column_1":
ri = cell.get("row_index", -1)
row_content_counts[ri] = row_content_counts.get(ri, 0) + 1
# Majority of rows must have ≥2 content cells
multi_col_rows = sum(1 for cnt in row_content_counts.values() if cnt >= 2)
if multi_col_rows < len(rows) * 0.4:
continue
# Exclude first and last non-header rows — these are typically
# page numbers or footer text, not headings.
non_header_rows = [r for r in rows if not r.get("is_header")]
if len(non_header_rows) < 3:
continue
first_ri = non_header_rows[0]["index"]
last_ri = non_header_rows[-1]["index"]
heading_row_indices = []
for row in rows:
if row.get("is_header"):
continue
ri = row["index"]
if ri == first_ri or ri == last_ri:
continue
row_cells = [c for c in cells if c.get("row_index") == ri]
content_cells = [
c for c in row_cells
if c.get("col_type", "").startswith("column_")
and c.get("col_type") != "column_1"
]
if len(content_cells) != 1:
continue
cell = content_cells[0]
# Not in the last column (continuation/example lines)
if cell.get("col_index") == last_col:
continue
text = (cell.get("text") or "").strip()
if not text or text.startswith("["):
continue
# Skip garbled IPA without brackets (e.g. "ska:f ska:vz")
# but NOT text with real IPA symbols (e.g. "Theme [θˈiːm]")
_REAL_IPA_CHARS = set("ˈˌəɪɛɒʊʌæɑɔʃʒθðŋ")
if _text_has_garbled_ipa(text) and not any(c in _REAL_IPA_CHARS for c in text):
continue
heading_row_indices.append(ri)
for hri in heading_row_indices:
header_cells = [c for c in cells if c.get("row_index") == hri]
if not header_cells:
continue
# Collect all word_boxes and text
all_wb = []
all_text_parts = []
for hc in sorted(header_cells, key=lambda c: c["col_index"]):
all_wb.extend(hc.get("word_boxes", []))
if hc.get("text", "").strip():
all_text_parts.append(hc["text"].strip())
first_col_idx = min(hc["col_index"] for hc in header_cells)
# Remove old cells for this row, add spanning heading cell
z["cells"] = [c for c in z["cells"] if c.get("row_index") != hri]
if all_wb:
x_min = min(wb["left"] for wb in all_wb)
y_min = min(wb["top"] for wb in all_wb)
x_max = max(wb["left"] + wb["width"] for wb in all_wb)
y_max = max(wb["top"] + wb["height"] for wb in all_wb)
else:
# Fallback to first cell bbox
bp = header_cells[0].get("bbox_px", {})
x_min = bp.get("x", 0)
y_min = bp.get("y", 0)
x_max = x_min + bp.get("w", 0)
y_max = y_min + bp.get("h", 0)
zone_idx = z.get("zone_index", 0)
z["cells"].append({
"cell_id": f"Z{zone_idx}_R{hri:02d}_C{first_col_idx}",
"zone_index": zone_idx,
"row_index": hri,
"col_index": first_col_idx,
"col_type": "heading",
"text": " ".join(all_text_parts),
"confidence": 0.0,
"bbox_px": {"x": x_min, "y": y_min,
"w": x_max - x_min, "h": y_max - y_min},
"bbox_pct": {
"x": round(x_min / img_w * 100, 2) if img_w else 0,
"y": round(y_min / img_h * 100, 2) if img_h else 0,
"w": round((x_max - x_min) / img_w * 100, 2) if img_w else 0,
"h": round((y_max - y_min) / img_h * 100, 2) if img_h else 0,
},
"word_boxes": all_wb,
"ocr_engine": "words_first",
"is_bold": False,
})
for row in rows:
if row["index"] == hri:
row["is_header"] = True
heading_count += 1
return heading_count
def _detect_header_rows(
rows: List[Dict],
zone_words: List[Dict],
zone_y: int,
columns: Optional[List[Dict]] = None,
skip_first_row_header: bool = False,
) -> List[int]:
"""Detect header rows: first-row heuristic + spanning header detection.
A "spanning header" is a row whose words stretch across multiple column
boundaries (e.g. "Unit4: Bonnie Scotland" centred across 4 columns).
"""
if len(rows) < 2:
return []
headers = []
if not skip_first_row_header:
first_row = rows[0]
second_row = rows[1]
# Gap between first and second row > 0.5x average row height
avg_h = sum(r["y_max"] - r["y_min"] for r in rows) / len(rows)
gap = second_row["y_min"] - first_row["y_max"]
if gap > avg_h * 0.5:
headers.append(0)
# Also check if first row words are taller than average (bold/header text)
all_heights = [w["height"] for w in zone_words]
median_h = sorted(all_heights)[len(all_heights) // 2] if all_heights else 20
first_row_words = [
w for w in zone_words
if first_row["y_min"] <= w["top"] + w["height"] / 2 <= first_row["y_max"]
]
if first_row_words:
first_h = max(w["height"] for w in first_row_words)
if first_h > median_h * 1.3:
if 0 not in headers:
headers.append(0)
# Note: Spanning-header detection (rows spanning all columns) has been
# disabled because it produces too many false positives on vocabulary
# worksheets where IPA transcriptions or short entries naturally span
# multiple columns with few words. The first-row heuristic above is
# sufficient for detecting real headers.
return headers
def _build_zone_grid(
zone_words: List[Dict],
zone_x: int,
zone_y: int,
zone_w: int,
zone_h: int,
zone_index: int,
img_w: int,
img_h: int,
global_columns: Optional[List[Dict]] = None,
skip_first_row_header: bool = False,
) -> Dict[str, Any]:
"""Build columns, rows, cells for a single zone from its words.
Args:
global_columns: If provided, use these pre-computed column boundaries
instead of detecting columns per zone. Used for content zones so
that all content zones (above/between/below boxes) share the same
column structure. Box zones always detect columns independently.
"""
if not zone_words:
return {
"columns": [],
"rows": [],
"cells": [],
"header_rows": [],
}
# Cluster rows first (needed for column alignment analysis)
rows = _cluster_rows(zone_words)
# Diagnostic logging for small/medium zones (box zones typically have 40-60 words)
if len(zone_words) <= 60:
import statistics as _st
_heights = [w['height'] for w in zone_words if w.get('height', 0) > 0]
_med_h = _st.median(_heights) if _heights else 20
_y_tol = max(_med_h * 0.5, 5)
logger.info(
"zone %d row-clustering: %d words, median_h=%.0f, y_tol=%.1f%d rows",
zone_index, len(zone_words), _med_h, _y_tol, len(rows),
)
for w in sorted(zone_words, key=lambda ww: (ww['top'], ww['left'])):
logger.info(
" zone %d word: y=%d x=%d h=%d w=%d '%s'",
zone_index, w['top'], w['left'], w['height'], w['width'],
w.get('text', '')[:40],
)
for r in rows:
logger.info(
" zone %d row %d: y_min=%d y_max=%d y_center=%.0f",
zone_index, r['index'], r['y_min'], r['y_max'], r['y_center'],
)
# Use global columns if provided, otherwise detect per zone
columns = global_columns if global_columns else _cluster_columns_by_alignment(zone_words, zone_w, rows)
# Merge inline marker columns (bullets, numbering) into adjacent text
if not global_columns:
columns = _merge_inline_marker_columns(columns, zone_words)
if not columns or not rows:
return {
"columns": [],
"rows": [],
"cells": [],
"header_rows": [],
}
# Build cells
cells = _build_cells(zone_words, columns, rows, img_w, img_h)
# Prefix cell IDs with zone index
for cell in cells:
cell["cell_id"] = f"Z{zone_index}_{cell['cell_id']}"
cell["zone_index"] = zone_index
# Detect header rows (pass columns for spanning header detection)
header_rows = _detect_header_rows(rows, zone_words, zone_y, columns,
skip_first_row_header=skip_first_row_header)
# Merge cells in spanning header rows into a single col-0 cell
if header_rows and len(columns) >= 2:
for hri in header_rows:
header_cells = [c for c in cells if c["row_index"] == hri]
if len(header_cells) <= 1:
continue
# Collect all word_boxes and text from all columns
all_wb = []
all_text_parts = []
for hc in sorted(header_cells, key=lambda c: c["col_index"]):
all_wb.extend(hc.get("word_boxes", []))
if hc.get("text", "").strip():
all_text_parts.append(hc["text"].strip())
# Remove all header cells, replace with one spanning cell
cells = [c for c in cells if c["row_index"] != hri]
if all_wb:
x_min = min(wb["left"] for wb in all_wb)
y_min = min(wb["top"] for wb in all_wb)
x_max = max(wb["left"] + wb["width"] for wb in all_wb)
y_max = max(wb["top"] + wb["height"] for wb in all_wb)
cells.append({
"cell_id": f"R{hri:02d}_C0",
"row_index": hri,
"col_index": 0,
"col_type": "spanning_header",
"text": " ".join(all_text_parts),
"confidence": 0.0,
"bbox_px": {"x": x_min, "y": y_min,
"w": x_max - x_min, "h": y_max - y_min},
"bbox_pct": {
"x": round(x_min / img_w * 100, 2) if img_w else 0,
"y": round(y_min / img_h * 100, 2) if img_h else 0,
"w": round((x_max - x_min) / img_w * 100, 2) if img_w else 0,
"h": round((y_max - y_min) / img_h * 100, 2) if img_h else 0,
},
"word_boxes": all_wb,
"ocr_engine": "words_first",
"is_bold": True,
})
# Convert columns to output format with percentages
out_columns = []
for col in columns:
x_min = col["x_min"]
x_max = col["x_max"]
out_columns.append({
"index": col["index"],
"label": col["type"],
"x_min_px": round(x_min),
"x_max_px": round(x_max),
"x_min_pct": round(x_min / img_w * 100, 2) if img_w else 0,
"x_max_pct": round(x_max / img_w * 100, 2) if img_w else 0,
"bold": False,
})
# Convert rows to output format with percentages
out_rows = []
for row in rows:
out_rows.append({
"index": row["index"],
"y_min_px": round(row["y_min"]),
"y_max_px": round(row["y_max"]),
"y_min_pct": round(row["y_min"] / img_h * 100, 2) if img_h else 0,
"y_max_pct": round(row["y_max"] / img_h * 100, 2) if img_h else 0,
"is_header": row["index"] in header_rows,
})
return {
"columns": out_columns,
"rows": out_rows,
"cells": cells,
"header_rows": header_rows,
"_raw_columns": columns, # internal: for propagation to other zones
}
def _get_content_bounds(words: List[Dict]) -> tuple:
"""Get content bounds from word positions."""
if not words:
return 0, 0, 0, 0
x_min = min(w["left"] for w in words)
y_min = min(w["top"] for w in words)
x_max = max(w["left"] + w["width"] for w in words)
y_max = max(w["top"] + w["height"] for w in words)
return x_min, y_min, x_max - x_min, y_max - y_min
def _filter_decorative_margin(
words: List[Dict],
img_w: int,
log: Any,
session_id: str,
) -> None:
"""Remove words that belong to a decorative alphabet strip on a margin.
Some vocabulary worksheets have a vertical AZ alphabet graphic along
the left or right edge. OCR reads each letter as an isolated single-
character word. These decorative elements are not content and confuse
column/row detection.
Detection criteria (phase 1 — find the strip using single-char words):
- Words are in the outer 30% of the page (left or right)
- Nearly all words are single characters (letters or digits)
- At least 8 such words form a vertical strip (≥8 unique Y positions)
- Average horizontal spread of the strip is small (< 80px)
Phase 2 — once a strip is confirmed, also remove any short word (≤3
chars) in the same narrow x-range. This catches multi-char OCR
artifacts like "Vv" that belong to the same decorative element.
Modifies *words* in place.
"""
if not words or img_w <= 0:
return
margin_cutoff = img_w * 0.30
# Phase 1: find candidate strips using single-char words
left_strip = [
w for w in words
if len((w.get("text") or "").strip()) == 1
and w["left"] + w.get("width", 0) / 2 < margin_cutoff
]
right_strip = [
w for w in words
if len((w.get("text") or "").strip()) == 1
and w["left"] + w.get("width", 0) / 2 > img_w - margin_cutoff
]
for strip, side in [(left_strip, "left"), (right_strip, "right")]:
if len(strip) < 8:
continue
# Check vertical distribution: should have many distinct Y positions
y_centers = sorted(set(
int(w["top"] + w.get("height", 0) / 2) // 20 * 20 # bucket
for w in strip
))
if len(y_centers) < 6:
continue
# Check horizontal compactness
x_positions = [w["left"] for w in strip]
x_min = min(x_positions)
x_max = max(x_positions)
x_spread = x_max - x_min
if x_spread > 80:
continue
# Phase 2: strip confirmed — also collect short words in same x-range
# Expand x-range slightly to catch neighbors (e.g. "Vv" next to "U")
strip_x_lo = x_min - 20
strip_x_hi = x_max + 60 # word width + tolerance
all_strip_words = [
w for w in words
if len((w.get("text") or "").strip()) <= 3
and strip_x_lo <= w["left"] <= strip_x_hi
and (w["left"] + w.get("width", 0) / 2 < margin_cutoff
if side == "left"
else w["left"] + w.get("width", 0) / 2 > img_w - margin_cutoff)
]
strip_set = set(id(w) for w in all_strip_words)
before = len(words)
words[:] = [w for w in words if id(w) not in strip_set]
removed = before - len(words)
if removed:
log.info(
"build-grid session %s: removed %d decorative %s-margin words "
"(strip x=%d-%d)",
session_id, removed, side, strip_x_lo, strip_x_hi,
)
def _filter_footer_words(
words: List[Dict],
img_h: int,
log: Any,
session_id: str,
) -> None:
"""Remove isolated words in the bottom 5% of the page (page numbers).
Modifies *words* in place.
"""
if not words or img_h <= 0:
return
footer_y = img_h * 0.95
footer_words = [
w for w in words
if w["top"] + w.get("height", 0) / 2 > footer_y
]
if not footer_words:
return
# Only remove if footer has very few words (≤ 3) with short text
total_text = "".join((w.get("text") or "").strip() for w in footer_words)
if len(footer_words) <= 3 and len(total_text) <= 10:
footer_set = set(id(w) for w in footer_words)
words[:] = [w for w in words if id(w) not in footer_set]
log.info(
"build-grid session %s: removed %d footer words ('%s')",
session_id, len(footer_words), total_text,
)
def _filter_header_junk(
words: List[Dict],
img_h: int,
log: Any,
session_id: str,
) -> None:
"""Remove OCR junk from header illustrations above the real content.
Textbook pages often have decorative header graphics (illustrations,
icons) that OCR reads as low-confidence junk characters. Real content
typically starts further down the page.
Algorithm:
1. Find the "content start" — the first Y position where a dense
horizontal row of 3+ high-confidence words begins.
2. Above that line, remove words with conf < 75 and text ≤ 3 chars.
These are almost certainly OCR artifacts from illustrations.
Modifies *words* in place.
"""
if not words or img_h <= 0:
return
# --- Find content start: first horizontal row with ≥3 high-conf words ---
# Sort words by Y
sorted_by_y = sorted(words, key=lambda w: w["top"])
content_start_y = 0
_ROW_TOLERANCE = img_h * 0.02 # words within 2% of page height = same row
_MIN_ROW_WORDS = 3
_MIN_CONF = 80
i = 0
while i < len(sorted_by_y):
row_y = sorted_by_y[i]["top"]
# Collect words in this row band
row_words = []
j = i
while j < len(sorted_by_y) and sorted_by_y[j]["top"] - row_y < _ROW_TOLERANCE:
row_words.append(sorted_by_y[j])
j += 1
# Count high-confidence words with real text (> 1 char)
high_conf = [
w for w in row_words
if w.get("conf", 0) >= _MIN_CONF
and len((w.get("text") or "").strip()) > 1
]
if len(high_conf) >= _MIN_ROW_WORDS:
content_start_y = row_y
break
i = j if j > i else i + 1
if content_start_y <= 0:
return # no clear content start found
# --- Remove low-conf short junk above content start ---
junk = [
w for w in words
if w["top"] + w.get("height", 0) < content_start_y
and w.get("conf", 0) < 75
and len((w.get("text") or "").strip()) <= 3
]
if not junk:
return
junk_set = set(id(w) for w in junk)
before = len(words)
words[:] = [w for w in words if id(w) not in junk_set]
removed = before - len(words)
if removed:
log.info(
"build-grid session %s: removed %d header junk words above y=%d "
"(content start)",
session_id, removed, content_start_y,
)
# ---------------------------------------------------------------------------
# Core computation (used by build-grid endpoint and regression tests)
# ---------------------------------------------------------------------------
async def _build_grid_core(session_id: str, session: dict) -> dict:
"""Core grid building logic — pure computation, no HTTP or DB side effects.
Args:
session_id: Session identifier (for logging and image loading).
session: Full session dict from get_session_db().
Returns:
StructuredGrid result dict.
Raises:
ValueError: If session data is incomplete.
"""
t0 = time.time()
# 1. Validate and load word results
word_result = session.get("word_result")
if not word_result or not word_result.get("cells"):
raise ValueError("No word results found. Run paddle-kombi or rapid-kombi first.")
img_w = word_result.get("image_width", 0)
img_h = word_result.get("image_height", 0)
if not img_w or not img_h:
raise ValueError("Missing image dimensions in word_result")
# 2. Flatten all word boxes from cells
all_words = _flatten_word_boxes(word_result["cells"])
if not all_words:
raise ValueError("No word boxes found in cells")
logger.info("build-grid session %s: %d words from %d cells",
session_id, len(all_words), len(word_result["cells"]))
# 2b. Filter decorative margin columns (alphabet graphics).
# Some worksheets have a decorative alphabet strip along one margin
# (A-Z in a graphic). OCR reads these as single-char words aligned
# vertically. Detect and remove them before grid building.
_filter_decorative_margin(all_words, img_w, logger, session_id)
# 2c. Filter footer rows (page numbers at the very bottom).
# Isolated short text in the bottom 5% of the page is typically a
# page number ("64", "S. 12") and not real content.
_filter_footer_words(all_words, img_h, logger, session_id)
# 2c2. Filter OCR junk from header illustrations.
# Low-confidence short fragments above the first real content row.
_filter_header_junk(all_words, img_h, logger, session_id)
# 2d. Filter words inside user-defined exclude regions (from Structure step).
# These are explicitly marked by the user, so ALL words inside are removed
# regardless of confidence.
structure_result = session.get("structure_result")
exclude_rects = []
if structure_result:
for er in structure_result.get("exclude_regions", []):
exclude_rects.append({
"x": er["x"], "y": er["y"],
"w": er["w"], "h": er["h"],
})
if exclude_rects:
before = len(all_words)
filtered = []
for w in all_words:
w_cx = w["left"] + w.get("width", 0) / 2
w_cy = w["top"] + w.get("height", 0) / 2
inside = any(
er["x"] <= w_cx <= er["x"] + er["w"]
and er["y"] <= w_cy <= er["y"] + er["h"]
for er in exclude_rects
)
if not inside:
filtered.append(w)
removed = before - len(filtered)
if removed:
all_words = filtered
logger.info(
"build-grid session %s: removed %d words inside %d user exclude region(s)",
session_id, removed, len(exclude_rects),
)
# 2e. Filter words inside detected graphic/image regions
# Only remove LOW-CONFIDENCE words (likely OCR artifacts from images).
# High-confidence words are real text even if they overlap a detected
# graphic region (e.g. colored text that graphic detection couldn't
# fully distinguish from an image).
_GRAPHIC_CONF_THRESHOLD = 50 # keep words with conf >= 50
graphic_rects = []
if structure_result:
for g in structure_result.get("graphics", []):
graphic_rects.append({
"x": g["x"], "y": g["y"],
"w": g["w"], "h": g["h"],
})
if graphic_rects:
before = len(all_words)
filtered = []
for w in all_words:
w_cx = w["left"] + w.get("width", 0) / 2
w_cy = w["top"] + w.get("height", 0) / 2
inside = any(
gr["x"] <= w_cx <= gr["x"] + gr["w"]
and gr["y"] <= w_cy <= gr["y"] + gr["h"]
for gr in graphic_rects
)
if inside and w.get("conf", 0) < _GRAPHIC_CONF_THRESHOLD:
continue # remove low-confidence artifact
filtered.append(w)
removed = before - len(filtered)
if removed:
all_words = filtered
logger.info(
"build-grid session %s: removed %d low-conf words inside %d graphic region(s)",
session_id, removed, len(graphic_rects),
)
# 3. Load image for box detection
img_png = await get_session_image(session_id, "cropped")
if not img_png:
img_png = await get_session_image(session_id, "dewarped")
if not img_png:
img_png = await get_session_image(session_id, "original")
zones_data: List[Dict[str, Any]] = []
boxes_detected = 0
recovered_count = 0
img_bgr = None
content_x, content_y, content_w, content_h = _get_content_bounds(all_words)
if img_png:
# Decode image for color detection + box detection
arr = np.frombuffer(img_png, dtype=np.uint8)
img_bgr = cv2.imdecode(arr, cv2.IMREAD_COLOR)
if img_bgr is not None:
# --- Recover colored text that OCR missed (before grid building) ---
recovered = recover_colored_text(img_bgr, all_words)
if recovered and graphic_rects:
# Filter recovered chars inside graphic regions
recovered = [
r for r in recovered
if not any(
gr["x"] <= r["left"] + r.get("width", 0) / 2 <= gr["x"] + gr["w"]
and gr["y"] <= r["top"] + r.get("height", 0) / 2 <= gr["y"] + gr["h"]
for gr in graphic_rects
)
]
if recovered:
recovered_count = len(recovered)
all_words.extend(recovered)
logger.info(
"build-grid session %s: +%d recovered colored words",
session_id, recovered_count,
)
# Detect bordered boxes
boxes = detect_boxes(
img_bgr,
content_x=content_x,
content_w=content_w,
content_y=content_y,
content_h=content_h,
)
boxes_detected = len(boxes)
if boxes:
# Filter border ghost words before grid building
all_words, ghost_count = _filter_border_ghosts(all_words, boxes)
if ghost_count:
logger.info(
"build-grid session %s: removed %d border ghost words",
session_id, ghost_count,
)
# Split page into zones
page_zones = split_page_into_zones(
content_x, content_y, content_w, content_h, boxes
)
# Merge content zones separated by box zones
page_zones = _merge_content_zones_across_boxes(
page_zones, content_x, content_w
)
# --- Union columns from all content zones ---
# Each content zone detects columns independently. Narrow
# columns (page refs, markers) may appear in only one zone.
# Merge column split-points from ALL content zones so every
# zone shares the full column set.
# First pass: build grids per zone independently
zone_grids: List[Dict] = []
for pz in page_zones:
zone_words = _words_in_zone(
all_words, pz.y, pz.height, pz.x, pz.width
)
# Filter recovered single-char artifacts in ALL zones
# (decorative colored pixel blobs like !, ?, • from
# recover_colored_text that don't represent real text)
before = len(zone_words)
zone_words = [
w for w in zone_words
if not (
w.get("recovered")
and len(w.get("text", "").strip()) <= 2
)
]
removed = before - len(zone_words)
if removed:
logger.info(
"build-grid: filtered %d recovered artifacts from %s zone %d",
removed, pz.zone_type, pz.index,
)
# Filter words inside image overlay regions (merged box zones)
if pz.image_overlays:
before_ov = len(zone_words)
zone_words = [
w for w in zone_words
if not any(
ov["y"] <= w["top"] + w["height"] / 2 <= ov["y"] + ov["height"]
and ov["x"] <= w["left"] + w["width"] / 2 <= ov["x"] + ov["width"]
for ov in pz.image_overlays
)
]
ov_removed = before_ov - len(zone_words)
if ov_removed:
logger.info(
"build-grid: filtered %d words inside image overlays from zone %d",
ov_removed, pz.index,
)
grid = _build_zone_grid(
zone_words, pz.x, pz.y, pz.width, pz.height,
pz.index, img_w, img_h,
skip_first_row_header=bool(pz.image_overlays),
)
zone_grids.append({"pz": pz, "words": zone_words, "grid": grid})
# Second pass: merge column boundaries from all content zones
content_zones = [
zg for zg in zone_grids if zg["pz"].zone_type == "content"
]
if len(content_zones) > 1:
# Collect column split points (x_min of non-first columns)
all_split_xs: List[float] = []
for zg in content_zones:
raw_cols = zg["grid"].get("_raw_columns", [])
for col in raw_cols[1:]:
all_split_xs.append(col["x_min"])
if all_split_xs:
all_split_xs.sort()
merge_distance = max(25, int(content_w * 0.03))
merged_xs = [all_split_xs[0]]
for x in all_split_xs[1:]:
if x - merged_xs[-1] < merge_distance:
merged_xs[-1] = (merged_xs[-1] + x) / 2
else:
merged_xs.append(x)
total_cols = len(merged_xs) + 1
max_zone_cols = max(
len(zg["grid"].get("_raw_columns", []))
for zg in content_zones
)
# Apply union whenever it has at least as many
# columns as the best single zone. Even with the
# same count the union boundaries are better because
# they incorporate evidence from all zones.
if total_cols >= max_zone_cols:
cx_min = min(w["left"] for w in all_words)
cx_max = max(
w["left"] + w["width"] for w in all_words
)
merged_columns: List[Dict[str, Any]] = []
prev_x = cx_min
for i, sx in enumerate(merged_xs):
merged_columns.append({
"index": i,
"type": f"column_{i + 1}",
"x_min": prev_x,
"x_max": sx,
})
prev_x = sx
merged_columns.append({
"index": len(merged_xs),
"type": f"column_{len(merged_xs) + 1}",
"x_min": prev_x,
"x_max": cx_max,
})
# Re-build ALL content zones with merged columns
for zg in zone_grids:
pz = zg["pz"]
if pz.zone_type == "content":
grid = _build_zone_grid(
zg["words"], pz.x, pz.y,
pz.width, pz.height,
pz.index, img_w, img_h,
global_columns=merged_columns,
skip_first_row_header=bool(pz.image_overlays),
)
zg["grid"] = grid
logger.info(
"build-grid session %s: union of %d content "
"zones → %d merged columns (max single zone: %d)",
session_id, len(content_zones),
total_cols, max_zone_cols,
)
for zg in zone_grids:
pz = zg["pz"]
grid = zg["grid"]
# Remove internal _raw_columns before adding to response
grid.pop("_raw_columns", None)
zone_entry: Dict[str, Any] = {
"zone_index": pz.index,
"zone_type": pz.zone_type,
"bbox_px": {
"x": pz.x, "y": pz.y,
"w": pz.width, "h": pz.height,
},
"bbox_pct": {
"x": round(pz.x / img_w * 100, 2) if img_w else 0,
"y": round(pz.y / img_h * 100, 2) if img_h else 0,
"w": round(pz.width / img_w * 100, 2) if img_w else 0,
"h": round(pz.height / img_h * 100, 2) if img_h else 0,
},
"border": None,
"word_count": len(zg["words"]),
**grid,
}
if pz.box:
zone_entry["border"] = {
"thickness": pz.box.border_thickness,
"confidence": pz.box.confidence,
}
if pz.image_overlays:
zone_entry["image_overlays"] = pz.image_overlays
zones_data.append(zone_entry)
# 4. Fallback: no boxes detected → single zone with all words
if not zones_data:
# Filter recovered single-char artifacts (same as in zone loop above)
before = len(all_words)
filtered_words = [
w for w in all_words
if not (w.get("recovered") and len(w.get("text", "").strip()) <= 2)
]
removed = before - len(filtered_words)
if removed:
logger.info(
"build-grid session %s: filtered %d recovered artifacts (fallback zone)",
session_id, removed,
)
grid = _build_zone_grid(
filtered_words, content_x, content_y, content_w, content_h,
0, img_w, img_h,
)
grid.pop("_raw_columns", None)
zones_data.append({
"zone_index": 0,
"zone_type": "content",
"bbox_px": {
"x": content_x, "y": content_y,
"w": content_w, "h": content_h,
},
"bbox_pct": {
"x": round(content_x / img_w * 100, 2) if img_w else 0,
"y": round(content_y / img_h * 100, 2) if img_h else 0,
"w": round(content_w / img_w * 100, 2) if img_w else 0,
"h": round(content_h / img_h * 100, 2) if img_h else 0,
},
"border": None,
"word_count": len(all_words),
**grid,
})
# 4b. Remove junk rows: rows where ALL cells contain only short,
# low-confidence text (OCR noise, stray marks). Real vocabulary rows
# have at least one word with conf >= 50 or meaningful text length.
# Also remove "oversized stub" rows: rows with ≤2 very short words
# whose word-boxes are significantly taller than the median (e.g.
# large red page numbers like "( 9" that are not real text content).
_JUNK_CONF_THRESHOLD = 50
_JUNK_MAX_TEXT_LEN = 3
for z in zones_data:
cells = z.get("cells", [])
rows = z.get("rows", [])
if not cells or not rows:
continue
# Compute median word height across the zone for oversized detection
all_wb_heights = [
wb["height"]
for cell in cells
for wb in cell.get("word_boxes") or []
if wb.get("height", 0) > 0
]
median_wb_h = sorted(all_wb_heights)[len(all_wb_heights) // 2] if all_wb_heights else 28
junk_row_indices = set()
for row in rows:
ri = row["index"]
row_cells = [c for c in cells if c.get("row_index") == ri]
if not row_cells:
continue
row_wbs = [
wb for cell in row_cells
for wb in cell.get("word_boxes") or []
]
# Rule 1: ALL word_boxes are low-conf AND short text
all_junk = True
for wb in row_wbs:
text = (wb.get("text") or "").strip()
conf = wb.get("conf", 0)
if conf >= _JUNK_CONF_THRESHOLD or len(text) > _JUNK_MAX_TEXT_LEN:
all_junk = False
break
if all_junk and row_wbs:
junk_row_indices.add(ri)
continue
# Rule 2: oversized stub — ≤3 words, short total text,
# and word height > 1.8× median (page numbers, stray marks,
# OCR from illustration labels like "SEA &")
if len(row_wbs) <= 3:
total_text = "".join((wb.get("text") or "").strip() for wb in row_wbs)
max_h = max((wb.get("height", 0) for wb in row_wbs), default=0)
if len(total_text) <= 5 and max_h > median_wb_h * 1.8:
junk_row_indices.add(ri)
continue
# Rule 3: scattered debris — rows with only tiny fragments
# (e.g. OCR artifacts from illustrations/graphics).
# If the row has no word longer than 2 chars, it's noise.
longest = max(len((wb.get("text") or "").strip()) for wb in row_wbs)
if longest <= 2:
junk_row_indices.add(ri)
continue
if junk_row_indices:
z["cells"] = [c for c in cells if c.get("row_index") not in junk_row_indices]
z["rows"] = [r for r in rows if r["index"] not in junk_row_indices]
logger.info(
"build-grid: removed %d junk rows from zone %d: %s",
len(junk_row_indices), z["zone_index"],
sorted(junk_row_indices),
)
# 4c. Remove oversized word_boxes from individual cells.
# OCR artifacts from graphics/images (e.g. a huge "N" from a map image)
# have word heights 3-5x the median. Remove them per-word so they don't
# pollute cells that also contain valid text in other columns.
for z in zones_data:
cells = z.get("cells", [])
if not cells:
continue
all_wh = [
wb["height"]
for cell in cells
for wb in cell.get("word_boxes") or []
if wb.get("height", 0) > 0
]
if not all_wh:
continue
med_h = sorted(all_wh)[len(all_wh) // 2]
oversized_threshold = med_h * 3
removed_oversized = 0
for cell in cells:
wbs = cell.get("word_boxes") or []
filtered = [wb for wb in wbs if wb.get("height", 0) <= oversized_threshold]
if len(filtered) < len(wbs):
removed_oversized += len(wbs) - len(filtered)
cell["word_boxes"] = filtered
cell["text"] = " ".join(
wb.get("text", "").strip()
for wb in sorted(filtered, key=lambda w: (w.get("top", 0), w.get("left", 0)))
if wb.get("text", "").strip()
)
if removed_oversized:
# Remove cells that became empty after oversized removal
z["cells"] = [c for c in cells if c.get("word_boxes")]
logger.info(
"build-grid: removed %d oversized word_boxes (>%dpx) from zone %d",
removed_oversized, oversized_threshold, z.get("zone_index", 0),
)
# 5. Color annotation on final word_boxes in cells
if img_bgr is not None:
all_wb: List[Dict] = []
for z in zones_data:
for cell in z.get("cells", []):
all_wb.extend(cell.get("word_boxes", []))
detect_word_colors(img_bgr, all_wb)
# 5a. Heading detection by color + height (after color is available)
heading_count = _detect_heading_rows_by_color(zones_data, img_w, img_h)
if heading_count:
logger.info("Detected %d heading rows by color+height", heading_count)
# 5b. Fix unmatched parentheses in cell text
# OCR often misses opening "(" while detecting closing ")".
# If a cell's text has ")" without a matching "(", prepend "(".
for z in zones_data:
for cell in z.get("cells", []):
text = cell.get("text", "")
if ")" in text and "(" not in text:
cell["text"] = "(" + text
# 5c. IPA phonetic correction — replace garbled OCR phonetics with
# correct IPA from the dictionary (same as in the OCR pipeline).
# Only applies to vocabulary tables (≥3 columns: EN | article | DE).
# Single/two-column layouts are continuous text, not vocab tables.
all_cells = [cell for z in zones_data for cell in z.get("cells", [])]
total_cols = sum(len(z.get("columns", [])) for z in zones_data)
if total_cols >= 3:
# Find the column that contains IPA brackets → English headwords.
# Count cells with bracket patterns per col_type. The column with
# the most brackets is the headword column (IPA sits after or below
# headwords). Falls back to longest-average if no brackets found.
col_bracket_count: Dict[str, int] = {}
col_avg_len: Dict[str, List[int]] = {}
for cell in all_cells:
ct = cell.get("col_type", "")
txt = cell.get("text", "") or ""
col_avg_len.setdefault(ct, []).append(len(txt))
if ct.startswith("column_") and '[' in txt:
col_bracket_count[ct] = col_bracket_count.get(ct, 0) + 1
# Pick column with most bracket IPA patterns
en_col_type = None
if col_bracket_count:
en_col_type = max(col_bracket_count, key=col_bracket_count.get)
else:
# Fallback: longest average text
best_avg = 0
for ct, lengths in col_avg_len.items():
if not ct.startswith("column_"):
continue
avg = sum(lengths) / len(lengths) if lengths else 0
if avg > best_avg:
best_avg = avg
en_col_type = ct
if en_col_type:
for cell in all_cells:
if cell.get("col_type") == en_col_type:
cell["_orig_col_type"] = en_col_type
cell["col_type"] = "column_en"
fix_cell_phonetics(all_cells, pronunciation="british")
for cell in all_cells:
orig = cell.pop("_orig_col_type", None)
if orig:
cell["col_type"] = orig
# 5d. Fix IPA continuation cells — cells where the printed
# phonetic transcription wraps to a line below the headword.
# These contain garbled IPA (e.g. "[n, nn]", "[1uedtX,1]").
# Replace garbled text with proper IPA looked up from the
# headword in the previous row's same column.
# Note: We check ALL columns, not just en_col_type, because
# the EN headword column may not be the longest-average column.
_REAL_IPA_CHARS = set("ˈˌəɪɛɒʊʌæɑɔʃʒθðŋ")
ipa_cont_fixed = 0
for z in zones_data:
rows_sorted = sorted(z.get("rows", []), key=lambda r: r["index"])
z_cells = z.get("cells", [])
for idx, row in enumerate(rows_sorted):
if idx == 0:
continue
ri = row["index"]
row_cells = [c for c in z_cells if c.get("row_index") == ri]
for cell in row_cells:
ct = cell.get("col_type", "")
if not ct.startswith("column_"):
continue
cell_text = (cell.get("text") or "").strip()
if not cell_text:
continue
is_bracketed = (
cell_text.startswith('[') and cell_text.endswith(']')
)
if is_bracketed:
# Bracketed continuation: "[n, nn]", "[klaoz 'daun]"
# Text like "employee [im'ploi:]" is NOT fully
# bracketed and won't match here.
if not _text_has_garbled_ipa(cell_text):
continue
# Already has proper IPA brackets → skip
if re.search(r'\[[^\]]*[ˈˌəɪɛɒʊʌæɑɔʃʒθðŋ][^\]]*\]', cell_text):
continue
else:
# Unbracketed continuation: "ska:f ska:vz",
# "'sekandarr sku:l". Only treat as IPA
# continuation if this is the ONLY content cell
# in the row (single-cell row) and the text is
# garbled IPA without real IPA Unicode symbols.
content_cells_in_row = [
c for c in row_cells
if c.get("col_type", "").startswith("column_")
and c.get("col_type") != "column_1"
]
if len(content_cells_in_row) != 1:
continue
if not _text_has_garbled_ipa(cell_text):
continue
# Has real IPA symbols → already fixed or valid
if any(c in _REAL_IPA_CHARS for c in cell_text):
continue
# Find headword in previous row, same column
prev_ri = rows_sorted[idx - 1]["index"]
prev_same_col = [
c for c in z_cells
if c.get("row_index") == prev_ri
and c.get("col_type") == ct
]
if not prev_same_col:
continue
prev_text = prev_same_col[0].get("text", "")
fixed = fix_ipa_continuation_cell(
cell_text, prev_text, pronunciation="british",
)
if fixed != cell_text:
cell["text"] = fixed
ipa_cont_fixed += 1
logger.info(
"IPA continuation R%d %s: '%s''%s'",
ri, ct, cell_text, fixed,
)
if ipa_cont_fixed:
logger.info("Fixed %d IPA continuation cells", ipa_cont_fixed)
# 5e. Heading detection by single-cell rows — black headings like
# "Theme" that have normal color and height but are the ONLY cell
# in their row (excluding page_ref column_1). Must run AFTER 5d
# so IPA continuation cells are already processed.
single_heading_count = _detect_heading_rows_by_single_cell(zones_data, img_w, img_h)
if single_heading_count:
logger.info("Detected %d heading rows by single-cell heuristic", single_heading_count)
duration = time.time() - t0
# 6. Build result
total_cells = sum(len(z.get("cells", [])) for z in zones_data)
total_columns = sum(len(z.get("columns", [])) for z in zones_data)
total_rows = sum(len(z.get("rows", [])) for z in zones_data)
# Collect color statistics from all word_boxes in cells
color_stats: Dict[str, int] = {}
for z in zones_data:
for cell in z.get("cells", []):
for wb in cell.get("word_boxes", []):
cn = wb.get("color_name", "black")
color_stats[cn] = color_stats.get(cn, 0) + 1
# Compute layout metrics for faithful grid reconstruction
all_content_row_heights: List[float] = []
for z in zones_data:
for row in z.get("rows", []):
if not row.get("is_header", False):
h = row.get("y_max_px", 0) - row.get("y_min_px", 0)
if h > 0:
all_content_row_heights.append(h)
avg_row_height = (
sum(all_content_row_heights) / len(all_content_row_heights)
if all_content_row_heights else 30.0
)
font_size_suggestion = max(10, int(avg_row_height * 0.6))
result = {
"session_id": session_id,
"image_width": img_w,
"image_height": img_h,
"zones": zones_data,
"boxes_detected": boxes_detected,
"summary": {
"total_zones": len(zones_data),
"total_columns": total_columns,
"total_rows": total_rows,
"total_cells": total_cells,
"total_words": len(all_words),
"recovered_colored": recovered_count,
"color_stats": color_stats,
},
"formatting": {
"bold_columns": [],
"header_rows": [],
},
"layout_metrics": {
"page_width_px": img_w,
"page_height_px": img_h,
"avg_row_height_px": round(avg_row_height, 1),
"font_size_suggestion_px": font_size_suggestion,
},
"duration_seconds": round(duration, 2),
}
return result
# ---------------------------------------------------------------------------
# Endpoints
# ---------------------------------------------------------------------------
@router.post("/sessions/{session_id}/build-grid")
async def build_grid(session_id: str):
"""Build a structured, zone-aware grid from existing Kombi word results.
Requires that paddle-kombi or rapid-kombi has already been run on the session.
Uses the image for box detection and the word positions for grid structuring.
Returns a StructuredGrid with zones, each containing their own
columns, rows, and cells — ready for the frontend Excel-like editor.
"""
session = await get_session_db(session_id)
if not session:
raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
try:
result = await _build_grid_core(session_id, session)
except ValueError as e:
raise HTTPException(status_code=400, detail=str(e))
# Persist to DB
await update_session_db(session_id, grid_editor_result=result)
logger.info(
"build-grid session %s: %d zones, %d cols, %d rows, %d cells, "
"%d boxes in %.2fs",
session_id,
len(result.get("zones", [])),
result.get("summary", {}).get("total_columns", 0),
result.get("summary", {}).get("total_rows", 0),
result.get("summary", {}).get("total_cells", 0),
result.get("boxes_detected", 0),
result.get("duration_seconds", 0),
)
return result
@router.post("/sessions/{session_id}/save-grid")
async def save_grid(session_id: str, request: Request):
"""Save edited grid data from the frontend Excel-like editor.
Receives the full StructuredGrid with user edits (text changes,
formatting changes like bold columns, header rows, etc.) and
persists it to the session's grid_editor_result.
"""
session = await get_session_db(session_id)
if not session:
raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
body = await request.json()
# Validate basic structure
if "zones" not in body:
raise HTTPException(status_code=400, detail="Missing 'zones' in request body")
# Preserve metadata from the original build
existing = session.get("grid_editor_result") or {}
result = {
"session_id": session_id,
"image_width": body.get("image_width", existing.get("image_width", 0)),
"image_height": body.get("image_height", existing.get("image_height", 0)),
"zones": body["zones"],
"boxes_detected": body.get("boxes_detected", existing.get("boxes_detected", 0)),
"summary": body.get("summary", existing.get("summary", {})),
"formatting": body.get("formatting", existing.get("formatting", {})),
"duration_seconds": existing.get("duration_seconds", 0),
"edited": True,
}
await update_session_db(session_id, grid_editor_result=result)
logger.info("save-grid session %s: %d zones saved", session_id, len(body["zones"]))
return {"session_id": session_id, "saved": True}
@router.get("/sessions/{session_id}/grid-editor")
async def get_grid(session_id: str):
"""Retrieve the current grid editor state for a session."""
session = await get_session_db(session_id)
if not session:
raise HTTPException(status_code=404, detail=f"Session {session_id} not found")
result = session.get("grid_editor_result")
if not result:
raise HTTPException(
status_code=404,
detail="No grid editor data. Run build-grid first.",
)
return result