Fix: Sidebar scrollable + add Eltern-Portal nav link
overflow-hidden → overflow-y-auto so all nav items are reachable. Added /parent (Eltern-Portal) link with people icon. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
Benjamin Admin
404
klausur-service/backend/ocr/words_first.py
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404
klausur-service/backend/ocr/words_first.py
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"""
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Words-First Grid Builder (Bottom-Up).
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Builds a cell grid from Tesseract word_boxes directly, without requiring
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pre-detected columns or rows. Algorithm:
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1. Cluster words into columns by X-gap analysis
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2. Cluster words into rows by Y-proximity
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3. Build cells at (column, row) intersections
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Returns the same (cells, columns_meta) format as build_cell_grid_v2().
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Lizenz: Apache 2.0 (kommerziell nutzbar)
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DATENSCHUTZ: Alle Verarbeitung erfolgt lokal.
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"""
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import logging
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import re
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import statistics
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from typing import Any, Dict, List, Optional, Tuple
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from cv_ocr_engines import (
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_group_words_into_lines,
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_words_to_reading_order_text,
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)
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logger = logging.getLogger(__name__)
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# ---------------------------------------------------------------------------
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# 1. Column clustering
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# ---------------------------------------------------------------------------
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def _cluster_columns(
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words: List[Dict],
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img_w: int,
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min_gap_pct: float = 3.0,
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max_columns: Optional[int] = None,
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) -> List[Dict[str, Any]]:
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"""Cluster words into columns by finding large horizontal gaps.
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Args:
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max_columns: If set, limits the number of columns by merging
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the closest adjacent pairs until the count matches.
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Prevents phantom columns from degraded OCR.
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Returns a list of column dicts:
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[{'index': 0, 'type': 'column_1', 'x_min': ..., 'x_max': ...}, ...]
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sorted left-to-right.
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"""
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if not words:
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return []
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# Sort by X center
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sorted_w = sorted(words, key=lambda w: w['left'] + w['width'] / 2)
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# Collect word heights to compute adaptive threshold
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heights = [w['height'] for w in sorted_w if w.get('height', 0) > 0]
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median_h = statistics.median(heights) if heights else 30
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# Adaptive gap threshold: 3× median word height, but at least min_gap_pct of image width
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min_gap_px = max(median_h * 3, img_w * min_gap_pct / 100) if img_w > 0 else median_h * 3
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# Find X-gap boundaries between consecutive words (sorted by X-center)
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# For each word, compute right edge; for next word, compute left edge
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# Collect gaps with their sizes for max_columns enforcement
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gaps: List[Tuple[float, float]] = [] # (gap_size, split_x)
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for i in range(len(sorted_w) - 1):
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right_edge = sorted_w[i]['left'] + sorted_w[i]['width']
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left_edge = sorted_w[i + 1]['left']
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gap = left_edge - right_edge
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if gap > min_gap_px:
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split_x = (right_edge + left_edge) / 2
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gaps.append((gap, split_x))
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# If max_columns is set, keep only the (max_columns - 1) largest gaps
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if max_columns and len(gaps) >= max_columns:
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gaps.sort(key=lambda g: g[0], reverse=True)
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gaps = gaps[:max_columns - 1]
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logger.info(
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f"_cluster_columns: limited to {max_columns} columns "
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f"(removed {len(gaps) + max_columns - 1 - (max_columns - 1)} smallest gaps)"
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)
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boundaries = sorted(g[1] for g in gaps)
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# Build column ranges from boundaries
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col_edges = [0.0] + boundaries + [float(img_w)]
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columns = []
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for ci in range(len(col_edges) - 1):
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columns.append({
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'index': ci,
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'type': f'column_{ci + 1}' if len(col_edges) > 2 else 'column_text',
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'x_min': col_edges[ci],
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'x_max': col_edges[ci + 1],
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})
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return columns
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# ---------------------------------------------------------------------------
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# 2. Row clustering
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# ---------------------------------------------------------------------------
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def _cluster_rows(
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words: List[Dict],
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) -> List[Dict[str, Any]]:
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"""Cluster words into visual rows by Y-proximity.
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Uses half the median word height as Y-tolerance.
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Returns a list of row dicts:
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[{'index': 0, 'y_min': ..., 'y_max': ..., 'y_center': ...}, ...]
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sorted top-to-bottom.
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"""
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if not words:
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return []
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heights = [w['height'] for w in words if w.get('height', 0) > 0]
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median_h = statistics.median(heights) if heights else 20
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y_tol = max(median_h * 0.5, 5)
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lines = _group_words_into_lines(words, y_tolerance_px=int(y_tol))
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rows = []
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for ri, line_words in enumerate(lines):
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y_min = min(w['top'] for w in line_words)
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y_max = max(w['top'] + w['height'] for w in line_words)
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rows.append({
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'index': ri,
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'y_min': y_min,
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'y_max': y_max,
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'y_center': (y_min + y_max) / 2,
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})
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return rows
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# ---------------------------------------------------------------------------
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# 3. Build cells
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# ---------------------------------------------------------------------------
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def _assign_word_to_column(word: Dict, columns: List[Dict]) -> int:
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"""Return column index for a word based on overlap, then center, then nearest.
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Three-pass strategy (consistent with _assign_row_words_to_columns):
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1. Overlap-based: assign to column with maximum horizontal overlap.
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2. Midpoint-range: if no overlap, use midpoints between adjacent columns.
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3. Nearest center: last resort fallback.
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"""
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w_left = word['left']
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w_right = w_left + word['width']
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w_center = w_left + word['width'] / 2
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# Pass 1: overlap-based
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best_col = -1
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best_overlap = 0
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for col in columns:
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overlap = max(0, min(w_right, col['x_max']) - max(w_left, col['x_min']))
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if overlap > best_overlap:
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best_overlap = overlap
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best_col = col['index']
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if best_col >= 0 and best_overlap > 0:
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return best_col
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# Pass 2: midpoint-range (non-overlapping assignment zones)
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for ci, col in enumerate(columns):
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if ci == 0:
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assign_left = 0
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else:
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assign_left = (columns[ci - 1]['x_max'] + col['x_min']) / 2
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if ci == len(columns) - 1:
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assign_right = float('inf')
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else:
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assign_right = (col['x_max'] + columns[ci + 1]['x_min']) / 2
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if assign_left <= w_center < assign_right:
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return col['index']
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# Pass 3: nearest column center
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return min(columns, key=lambda c: abs((c['x_min'] + c['x_max']) / 2 - w_center))['index']
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def _assign_word_to_row(word: Dict, rows: List[Dict]) -> int:
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"""Return row index for a word based on its Y-center.
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When rows overlap (e.g. due to tall border-ghost characters inflating
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a row's y_max), prefer the row whose y_center is closest.
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"""
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y_center = word['top'] + word['height'] / 2
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# Find all rows whose y_range contains this word's center
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matching = [r for r in rows if r['y_min'] <= y_center <= r['y_max']]
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if matching:
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return min(matching, key=lambda r: abs(r['y_center'] - y_center))['index']
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# Fallback: nearest row by Y-center
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return min(rows, key=lambda r: abs(r['y_center'] - y_center))['index']
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def _build_cells(
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words: List[Dict],
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columns: List[Dict],
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rows: List[Dict],
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img_w: int,
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img_h: int,
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) -> List[Dict[str, Any]]:
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"""Build cell dicts from word assignments to (column, row) pairs."""
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if not columns or not rows:
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return []
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# Bucket words into (col_idx, row_idx)
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buckets: Dict[Tuple[int, int], List[Dict]] = {}
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for w in words:
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ci = _assign_word_to_column(w, columns)
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ri = _assign_word_to_row(w, rows)
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buckets.setdefault((ci, ri), []).append(w)
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cells = []
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for (ci, ri), cell_words in sorted(buckets.items(), key=lambda kv: (kv[0][1], kv[0][0])):
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col = columns[ci]
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row = rows[ri]
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# Compute tight bbox from actual word positions
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x_min = min(w['left'] for w in cell_words)
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y_min = min(w['top'] for w in cell_words)
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x_max = max(w['left'] + w['width'] for w in cell_words)
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y_max = max(w['top'] + w['height'] for w in cell_words)
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bw = x_max - x_min
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bh = y_max - y_min
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# Text from words in reading order
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text = _words_to_reading_order_text(cell_words, y_tolerance_px=max(10, int(bh * 0.4)))
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# Average confidence
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confs = [w.get('conf', 0) for w in cell_words if w.get('conf', 0) > 0]
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avg_conf = sum(confs) / len(confs) if confs else 0.0
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# Word boxes with absolute pixel coordinates (consistent with cv_cell_grid.py).
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# PaddleOCR returns phrase-level boxes (e.g. "competition [kompa'tifn]"),
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# but the overlay slide mechanism expects one box per word. Split multi-word
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# boxes into individual word positions proportional to character length.
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# Also split at "[" boundaries (IPA patterns like "badge[bxd3]").
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#
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# Sort in reading order: group by Y (same visual line), then sort by X.
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# Simple (top, left) sort fails when words on the same line have slightly
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# different top values (1-6px), causing wrong word order.
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y_tol_wb = max(10, int(bh * 0.4))
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reading_lines = _group_words_into_lines(cell_words, y_tolerance_px=y_tol_wb)
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ordered_cell_words = [w for line in reading_lines for w in line]
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word_boxes = []
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for w in ordered_cell_words:
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raw_text = w.get('text', '').strip()
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# Split by whitespace, at "[" boundaries (IPA), and after leading "!"
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# e.g. "badge[bxd3]" → ["badge", "[bxd3]"]
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# e.g. "profit['proft]" → ["profit", "['proft]"]
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# e.g. "!Betonung" → ["!", "Betonung"]
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tokens = re.split(r'\s+|(?=\[)|(?<=!)(?=[A-Za-z\u00c0-\u024f])', raw_text)
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tokens = [t for t in tokens if t] # remove empty strings
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if len(tokens) <= 1:
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# Single word — keep as-is
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word_boxes.append({
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'text': raw_text,
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'left': w['left'],
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'top': w['top'],
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'width': w['width'],
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'height': w['height'],
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'conf': w.get('conf', 0),
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})
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else:
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# Multi-word phrase — split proportionally by character count
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total_chars = sum(len(t) for t in tokens)
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if total_chars == 0:
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continue
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# Small gap between words (2% of box width per gap)
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n_gaps = len(tokens) - 1
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gap_px = w['width'] * 0.02
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usable_w = w['width'] - gap_px * n_gaps
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cursor = w['left']
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for t in tokens:
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token_w = max(1, usable_w * len(t) / total_chars)
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word_boxes.append({
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'text': t,
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'left': round(cursor),
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'top': w['top'],
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'width': round(token_w),
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'height': w['height'],
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'conf': w.get('conf', 0),
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})
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cursor += token_w + gap_px
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cells.append({
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'cell_id': f"R{ri:02d}_C{ci}",
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'row_index': ri,
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'col_index': ci,
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'col_type': col['type'],
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'text': text,
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'confidence': round(avg_conf, 1),
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'bbox_px': {'x': x_min, 'y': y_min, 'w': bw, 'h': bh},
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'bbox_pct': {
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'x': round(x_min / img_w * 100, 2) if img_w else 0,
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'y': round(y_min / img_h * 100, 2) if img_h else 0,
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'w': round(bw / img_w * 100, 2) if img_w else 0,
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'h': round(bh / img_h * 100, 2) if img_h else 0,
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},
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'word_boxes': word_boxes,
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'ocr_engine': 'words_first',
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'is_bold': False,
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})
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return cells
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# ---------------------------------------------------------------------------
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# 4. Public API
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# ---------------------------------------------------------------------------
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def build_grid_from_words(
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word_dicts: List[Dict],
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img_w: int,
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img_h: int,
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min_confidence: int = 30,
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box_rects: Optional[List[Dict]] = None,
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max_columns: Optional[int] = None,
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) -> Tuple[List[Dict[str, Any]], List[Dict[str, Any]]]:
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"""Build a cell grid bottom-up from Tesseract word boxes.
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Args:
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word_dicts: Flat list of word dicts with keys:
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text, left, top, width, height, conf
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(absolute pixel coordinates).
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img_w: Image width in pixels.
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img_h: Image height in pixels.
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min_confidence: Minimum OCR confidence to keep a word.
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box_rects: Optional list of box dicts with keys x, y, width, height.
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Words inside these boxes are excluded from column clustering
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(box-internal columns are detected separately in sub-sessions).
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Returns:
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(cells, columns_meta) — same format as build_cell_grid_v2().
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cells: list of cell dicts with cell_id, bbox_px, bbox_pct, etc.
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columns_meta: list of {'index', 'type', 'x', 'width'} dicts.
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"""
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if not word_dicts:
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logger.info("build_grid_from_words: no words — returning empty grid")
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return [], []
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# Filter by confidence
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words = [
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w for w in word_dicts
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if w.get('conf', 0) >= min_confidence and w.get('text', '').strip()
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]
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if not words:
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logger.info("build_grid_from_words: all words filtered (conf < %d)", min_confidence)
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return [], []
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logger.info("build_grid_from_words: %d words (after confidence filter from %d)", len(words), len(word_dicts))
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# Exclude words inside detected boxes — box columns are detected separately
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if box_rects:
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content_words = []
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for w in words:
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w_cx = w['left'] + w['width'] / 2
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w_cy = w['top'] + w['height'] / 2
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inside = any(
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b['x'] <= w_cx <= b['x'] + b['width']
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and b['y'] <= w_cy <= b['y'] + b['height']
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for b in box_rects
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)
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if not inside:
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content_words.append(w)
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excluded = len(words) - len(content_words)
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if excluded:
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logger.info("build_grid_from_words: excluded %d words inside %d box(es)",
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excluded, len(box_rects))
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words = content_words
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if not words:
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logger.info("build_grid_from_words: all words inside boxes — returning empty grid")
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return [], []
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# Step 1: cluster columns
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columns = _cluster_columns(words, img_w, max_columns=max_columns)
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logger.info("build_grid_from_words: %d column(s) detected%s",
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len(columns), f" (max={max_columns})" if max_columns else "")
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# Step 2: cluster rows
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rows = _cluster_rows(words)
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logger.info("build_grid_from_words: %d row(s) detected", len(rows))
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# Step 3: build cells
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cells = _build_cells(words, columns, rows, img_w, img_h)
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logger.info("build_grid_from_words: %d cells built", len(cells))
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# Build columns_meta in same format as build_cell_grid_v2
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columns_meta = []
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for col in columns:
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x = int(col['x_min'])
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w = int(col['x_max'] - col['x_min'])
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columns_meta.append({
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'index': col['index'],
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'type': col['type'],
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'x': x,
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'width': w,
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})
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return cells, columns_meta
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