Removes torch from ocr_wrapper

CHANGELOG.md

@@ -4,7 +4,7 @@ The version numbers are according to [Semantic Versioning](http://semver.org/).
 
 ## Release v0.0.x ()
 ### Added
-
+- Added possibility to deactivate using torch by setting the environment variable `OCR_WRAPPER_NO_TORCH`. By default, torch is used. The main use case for this to decreate import times of the library. If torch is not used, numpy and SciPy are used instead. Be aware that tilt correction is around 5x slower without torch.
 ### Fixed
 
 ### Changed

pyproject.toml

@@ -14,6 +14,7 @@ dependencies = [
     "torch",
     "torchvision",
     "numpy",
+    "scipy",
     "opentelemetry-api",
     "opentelemetry-sdk"
 ]

tests/test_tilt_correction.py

@@ -1,5 +1,13 @@
+import os
+
+import numpy as np
+import pytest
+from ocr_wrapper.tilt_correction import _closest_90_degree_distance, correct_tilt
+from PIL import Image
 from pytest import mark
-from ocr_wrapper.tilt_correction import _closest_90_degree_distance
+
+filedir = os.path.dirname(__file__)
+DATA_DIR = os.path.join(filedir, "data")
 
 
 @mark.parametrize(
@@ -25,3 +33,12 @@
 )
 def test_closest_90_degree_distance(angle, expected):
     assert _closest_90_degree_distance(angle) == expected
+
+
+@pytest.mark.parametrize("angle", np.linspace(0, 9, 15))
+def test_correct_tilt(angle):
+    file = os.path.join(DATA_DIR, "mixed_arabic.jpg")
+    img = Image.open(file)
+    rotated_img = img.rotate(angle)
+    _, detected_angle = correct_tilt(rotated_img)
+    assert pytest.approx(abs(detected_angle), abs=0.1) == angle