| | import unicodedata |
| | from typing import Dict, List, Tuple, Optional |
| |
|
| | def norm(text: str) -> str: |
| | """Text normalization: lowercase + remove whitespace/punctuation + keep alphanumerics only.""" |
| | if not text: |
| | return "" |
| | text = unicodedata.normalize('NFKC', text) |
| | text = text.lower() |
| | text = ''.join(c for c in text if c.isalnum()) |
| | return text |
| |
|
| | def poly_to_bbox(poly: List[List[float]]) -> Tuple[float, float, float, float]: |
| | """Convert polygon to bbox.""" |
| | xs = [p[0] for p in poly] |
| | ys = [p[1] for p in poly] |
| | return (min(xs), min(ys), max(xs), max(ys)) |
| |
|
| | def bbox_iou(box1: Tuple, box2: Tuple) -> float: |
| | """Compute IoU.""" |
| | x1_1, y1_1, x2_1, y2_1 = box1 |
| | x1_2, y1_2, x2_2, y2_2 = box2 |
| | xi1, yi1 = max(x1_1, x1_2), max(y1_1, y1_2) |
| | xi2, yi2 = min(x2_1, x2_2), min(y2_1, y2_2) |
| | inter = max(0, xi2 - xi1) * max(0, yi2 - yi1) |
| | union = (x2_1 - x1_1) * (y2_1 - y1_1) + (x2_2 - x1_2) * (y2_2 - y1_2) - inter |
| | return inter / union if union > 0 else 0.0 |
| |
|
| | def point_in_bbox(point: Tuple[float, float], bbox: Tuple) -> bool: |
| | """Check whether a point is inside a bbox.""" |
| | x, y = point |
| | x1, y1, x2, y2 = bbox |
| | return x1 <= x <= x2 and y1 <= y <= y2 |
| |
|
| | def bbox_center(bbox: Tuple) -> Tuple[float, float]: |
| | """Return the bbox center point.""" |
| | x1, y1, x2, y2 = bbox |
| | return ((x1 + x2) / 2, (y1 + y2) / 2) |
| |
|
| | def union_bboxes(bboxes: List[Tuple]) -> Tuple: |
| | """Merge multiple bboxes.""" |
| | if not bboxes: |
| | return (0, 0, 0, 0) |
| | x1 = min(b[0] for b in bboxes) |
| | y1 = min(b[1] for b in bboxes) |
| | x2 = max(b[2] for b in bboxes) |
| | y2 = max(b[3] for b in bboxes) |
| | return (x1, y1, x2, y2) |
| |
|
| | def group_into_lines(items: List[Dict], y_threshold: float = 10.0) -> List[List[Dict]]: |
| | """Cluster OCR items into lines by y-axis distance.""" |
| | if not items: |
| | return [] |
| | sorted_items = sorted(items, key=lambda it: (it['bbox'][1] + it['bbox'][3]) / 2) |
| | lines = [] |
| | current_line = [sorted_items[0]] |
| | |
| | for item in sorted_items[1:]: |
| | y_cur = (item['bbox'][1] + item['bbox'][3]) / 2 |
| | y_prev = (current_line[-1]['bbox'][1] + current_line[-1]['bbox'][3]) / 2 |
| | if abs(y_cur - y_prev) < y_threshold: |
| | current_line.append(item) |
| | else: |
| | lines.append(current_line) |
| | current_line = [item] |
| | lines.append(current_line) |
| | |
| | |
| | for line in lines: |
| | line.sort(key=lambda it: it['bbox'][0]) |
| | return lines |
