fix(ocr): move bounding bow rotation util to orientation.py

Signed-off-by: Clément Doumouro <clement.doumouro@gmail.com>

docling/models/tesseract_ocr_cli_model.py

@@ -21,11 +21,11 @@ from docling.datamodel.pipeline_options import (
 from docling.datamodel.settings import settings
 from docling.models.base_ocr_model import BaseOcrModel
 from docling.utils.ocr_utils import (
-    Box,
     map_tesseract_script,
     parse_tesseract_orientation,
     tesseract_box_to_bounding_rectangle,
 )
+from docling.utils.orientation import Box
 from docling.utils.profiling import TimeRecorder
 
 _log = logging.getLogger(__name__)

docling/utils/ocr_utils.py

@@ -1,13 +1,14 @@
-from typing import Optional, Tuple
+from typing import Optional
 
 from docling_core.types.doc import BoundingBox, CoordOrigin
 from docling_core.types.doc.page import BoundingRectangle
 
-_TESSERACT_ORIENTATIONS = {0, 90, 180, 270}
-
-Point = Tuple[float, float]
-Box = Tuple[float, float, float, float]
-Size = Tuple[int, int]
+from docling.utils.orientation import (
+    Box,
+    Size,
+    CLIPPED_ORIENTATIONS,
+    rotate_ltwh_bounding_box,
+)
 
 
 def map_tesseract_script(script: str) -> str:
@@ -21,45 +22,18 @@ def map_tesseract_script(script: str) -> str:
     return script
 
 
-def reverse_tesseract_preprocessing_rotation(
-    box: Box, orientation: int, rotated_im_size: Size
-) -> tuple[Point, Point, Point, Point]:
-    # The box is left top width height in TOPLEFT coordinates
-    # Bounding rectangle start with r_0 at the bottom left whatever the
-    # coordinate system. Then other corners are found rotating counterclockwise
-    l, t, w, h = box
-    rotated_im_w, rotated_im_h = rotated_im_size
-    if orientation == 0:
-        r0_x = l
-        r0_y = t + h
-        return (r0_x, r0_y), (r0_x + w, r0_y), (r0_x + w, r0_y - h), (r0_x, r0_y - h)
-    if orientation == 90:
-        r0_x = rotated_im_h - (t + h)
-        r0_y = l
-        return (r0_x, r0_y), (r0_x, r0_y + w), (r0_x + h, r0_y + w), (r0_x, r0_y + w)
-    if orientation == 180:
-        r0_x = rotated_im_w - l
-        r0_y = rotated_im_h - (t + h)
-        return (r0_x, r0_y), (r0_x - w, r0_y), (r0_x - w, r0_y + h), (r0_x, r0_y + h)
-    if orientation == 270:
-        r0_x = t + h
-        r0_y = rotated_im_w - l
-        return (r0_x, r0_y), (r0_x, r0_y - w), (r0_x - h, r0_y - w), (r0_x - h, r0_y)
-    msg = (
-        f"invalid tesseract document orientation {orientation}, "
-        f"expected orientation: {sorted(_TESSERACT_ORIENTATIONS)}"
-    )
-    raise ValueError(msg)
-
-
 def parse_tesseract_orientation(orientation: str) -> int:
+    # Tesseract orientation is [0, 90, 180, 270] clockwise, bounding rectangle angles
+    # are [0, 360[ counterclockwise
     parsed = int(orientation)
-    if parsed not in _TESSERACT_ORIENTATIONS:
+    if parsed not in CLIPPED_ORIENTATIONS:
         msg = (
             f"invalid tesseract document orientation {orientation}, "
-            f"expected orientation: {sorted(_TESSERACT_ORIENTATIONS)}"
+            f"expected orientation: {sorted(CLIPPED_ORIENTATIONS)}"
         )
         raise ValueError(msg)
+    parsed = -parsed
+    parsed %= 360
     return parsed
 
 
@@ -72,9 +46,7 @@ def tesseract_box_to_bounding_rectangle(
     rotated_image_size: Size,
 ) -> BoundingRectangle:
     # box is in the top, left, height, width format + top left orientation
-    r_0, r_1, r_2, r_3 = reverse_tesseract_preprocessing_rotation(
-        box, orientation, rotated_image_size
-    )
+    r_0, r_1, r_2, r_3 = rotate_ltwh_bounding_box(box, orientation, rotated_image_size)
     rect = BoundingRectangle(
         r_x0=r_0[0] / scale,
         r_y0=r_0[1] / scale,

docling/utils/orientation.py

@@ -1,13 +1,19 @@
 from collections import Counter
 from operator import itemgetter
+from typing import Tuple
 
 from docling_core.types.doc.page import TextCell
 
-_ORIENTATIONS = [0, 90, 180, 270]
+
+Point = Tuple[float, float]
+Box = Tuple[float, float, float, float]
+Size = Tuple[int, int]
+
+CLIPPED_ORIENTATIONS = [0, 90, 180, 270]
 
 
 def _clipped_orientation(angle: float) -> int:
-    return min((abs(angle - o) % 360, o) for o in _ORIENTATIONS)[1]
+    return min((abs(angle - o) % 360, o) for o in CLIPPED_ORIENTATIONS)[1]
 
 
 def detect_orientation(cells: list[TextCell]) -> int:
@@ -15,3 +21,34 @@ def detect_orientation(cells: list[TextCell]) -> int:
         return 0
     orientation_counter = Counter(_clipped_orientation(c.rect.angle_360) for c in cells)
     return max(orientation_counter.items(), key=itemgetter(1))[0]
+
+
+def rotate_ltwh_bounding_box(
+    box: Box, orientation: int, rotated_im_size: Size
+) -> tuple[Point, Point, Point, Point]:
+    # The box is left top width height in TOPLEFT coordinates
+    # Bounding rectangle start with r_0 at the bottom left whatever the
+    # coordinate system. Then other corners are found rotating counterclockwise
+    l, t, w, h = box
+    rotated_im_w, rotated_im_h = rotated_im_size
+    if orientation == 0:
+        r0_x = l
+        r0_y = t + h
+        return (r0_x, r0_y), (r0_x + w, r0_y), (r0_x + w, r0_y - h), (r0_x, r0_y - h)
+    if orientation == 90:
+        r0_x = t + h
+        r0_y = rotated_im_w - l
+        return (r0_x, r0_y), (r0_x, r0_y - w), (r0_x - h, r0_y - w), (r0_x - h, r0_y)
+    if orientation == 180:
+        r0_x = rotated_im_w - l
+        r0_y = rotated_im_h - (t + h)
+        return (r0_x, r0_y), (r0_x - w, r0_y), (r0_x - w, r0_y + h), (r0_x, r0_y + h)
+    if orientation == 270:
+        r0_x = rotated_im_h - (t + h)
+        r0_y = l
+        return (r0_x, r0_y), (r0_x, r0_y + w), (r0_x + h, r0_y + w), (r0_x, r0_y + w)
+    msg = (
+        f"orientation {orientation}, expected values in:"
+        f" {sorted(CLIPPED_ORIENTATIONS)}"
+    )
+    raise ValueError(msg)