Merge pull request #130 from sbrunner/dependabot/pip/scikit-image-0.19.0

Bump scikit-image from 0.18.3 to 0.19.0

Pipfile

@@ -5,7 +5,7 @@ name = "pypi"
 
 [packages]
 numpy = "==1.21.4"
-scikit-image = "==0.18.3"
+scikit-image = "==0.19.0"
 
 [dev-packages]
 pytest = "==6.2.5"

deskew/__init__.py

@@ -1,6 +1,7 @@
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple
 
 import numpy as np
+from skimage.color import rgb2gray, rgba2rgb
 from skimage.feature import canny
 from skimage.transform import hough_line, hough_line_peaks
 
@@ -55,11 +56,14 @@ def determine_skew_dev(
     Tuple[ImageTypeUint64, List[List[np.float64]], ImageTypeFloat64],
 ]:
     """Calculate skew angle."""
-    img = image
+    imagergb = rgba2rgb(image) if len(image.shape) == 3 and image.shape[2] == 4 else image
+    img = rgb2gray(imagergb) if len(imagergb.shape) == 3 else imagergb
     edges = canny(img, sigma=sigma)
     out, angles, distances = hough_line(edges, np.linspace(-np.pi / 2, np.pi / 2, num_angles, endpoint=False))
 
-    _, angles_peaks, _ = hough_line_peaks(out, angles, distances, num_peaks=num_peaks)
+    _, angles_peaks, _ = hough_line_peaks(
+        out, angles, distances, num_peaks=num_peaks, threshold=0.05 * np.max(out)
+    )
 
     absolute_deviations = [_calculate_deviation(k) for k in angles_peaks]
     average_deviation: np.float64 = np.mean(np.rad2deg(absolute_deviations))

mypy.ini

@@ -19,6 +19,3 @@ ignore_missing_imports = True
 
 [mypy-skimage.*]
 ignore_missing_imports = True
-
-[mypy-matplotlib.*]
-ignore_missing_imports = True

tests/test_deskew.py

@@ -2,7 +2,6 @@
 
 import pytest
 from skimage import io
-from skimage.color import rgb2gray
 
 from deskew import determine_skew
 
@@ -14,7 +13,7 @@
         ("2", pytest.approx(-2.0, abs=0.01)),
         ("3", pytest.approx(-6.0, abs=0.01)),
         ("4", pytest.approx(7.0, abs=0.01)),
-        ("5", pytest.approx(4.0, abs=0.01)),
+        ("5", pytest.approx(3.0, abs=0.01)),
         ("6", pytest.approx(-3.0, abs=0.01)),
         ("7", pytest.approx(3.0, abs=0.01)),
         ("8", pytest.approx(15.0, abs=0.01)),
@@ -26,8 +25,7 @@ def test_deskew(image, expected_angle):
         os.makedirs(root_folder)
 
     image = io.imread(os.path.join(os.path.dirname(__file__), f"deskew-{image}.png"))
-    grayscale = rgb2gray(image)
-    angle = determine_skew(grayscale)
+    angle = determine_skew(image)
     print(angle - expected_angle.expected)
     assert angle == expected_angle
 
@@ -37,8 +35,8 @@ def test_deskew(image, expected_angle):
     [
         ("1", pytest.approx(-1.4, abs=0.01)),
         ("2", pytest.approx(-2.1, abs=0.01)),
-        ("3", pytest.approx(-6.2, abs=0.01)),
-        ("4", pytest.approx(7.1, abs=0.01)),
+        ("3", pytest.approx(-6.3, abs=0.01)),
+        ("4", pytest.approx(7.0, abs=0.01)),
         ("5", pytest.approx(3.4, abs=0.01)),
         ("6", pytest.approx(-2.8, abs=0.01)),
         ("7", pytest.approx(3.7, abs=0.01)),
@@ -51,7 +49,6 @@ def test_deskew_higher_pressision(image, expected_angle):
         os.makedirs(root_folder)
 
     image = io.imread(os.path.join(os.path.dirname(__file__), f"deskew-{image}.png"))
-    grayscale = rgb2gray(image)
-    angle = determine_skew(grayscale, num_angles=1800)
+    angle = determine_skew(image, num_angles=1800)
     print(angle - expected_angle.expected)
     assert angle == expected_angle