Image loading now respects exif image rotation

beeref/fileio/image.py

@@ -21,17 +21,63 @@ from urllib import request
 
 from PyQt6 import QtGui
 
+import exif
+
 
 logger = logging.getLogger(__name__)
 
 
+def exif_rotated_image(path=None):
+    """Returns a QImage that is transformed according to the source's
+    orientation EXIF data.
+    """
+
+    img = QtGui.QImage(path)
+    if img.isNull():
+        return img
+
+    with open(path, 'rb') as f:
+        exifimg = exif.Image(f)
+
+    if 'orientation' in exifimg.list_all():
+        orientation = exifimg.orientation
+    else:
+        return img
+
+    transform = QtGui.QTransform()
+
+    if orientation == exif.Orientation.TOP_RIGHT:
+        return img.mirrored(horizontal=True, vertical=False)
+    if orientation == exif.Orientation.BOTTOM_RIGHT:
+        transform.rotate(180)
+        return img.transformed(transform)
+    if orientation == exif.Orientation.BOTTOM_LEFT:
+        return img.mirrored(horizontal=False, vertical=True)
+    if orientation == exif.Orientation.LEFT_TOP:
+        transform.rotate(90)
+        return img.transformed(transform).mirrored(
+            horizontal=True, vertical=False)
+    if orientation == exif.Orientation.RIGHT_TOP:
+        transform.rotate(90)
+        return img.transformed(transform)
+    if orientation == exif.Orientation.RIGHT_BOTTOM:
+        transform.rotate(270)
+        return img.transformed(transform).mirrored(
+            horizontal=True, vertical=False)
+    if orientation == exif.Orientation.LEFT_BOTTOM:
+        transform.rotate(270)
+        return img.transformed(transform)
+
+    return img
+
+
 def load_image(path):
     if isinstance(path, str):
-        return (QtGui.QImage(path), path)
+        return (exif_rotated_image(path), path)
     if path.isLocalFile():
-        return (QtGui.QImage(path.path()), path.path())
+        return (exif_rotated_image(path.path()), path.path())
 
-    img = QtGui.QImage()
+    img = exif_rotated_image()
     try:
         imgdata = request.urlopen(path.url()).read()
     except URLError as e:
@@ -42,5 +88,5 @@ def load_image(path):
             with open(fname, 'wb') as f:
                 f.write(imgdata)
                 logger.debug(f'Temporarily saved in: {fname}')
-            img = QtGui.QImage(fname)
+            img = exif_rotated_image(fname)
     return (img, path.url())

setup.py

@@ -11,6 +11,7 @@ setup(
     install_requires=[
         'pyQt6>=6.1',
         'rectangle-packer>=2.0.1',
+        'exif',
     ],
     packages=['beeref'],
     entry_points={

tests/fileio/test_image.py

@@ -1,8 +1,52 @@
+import math
+import os.path
+
 import httpretty
+import pytest
 
-from PyQt6 import QtCore
+from PyQt6 import QtCore, QtGui
 
-from beeref.fileio.image import load_image
+from beeref.fileio.image import exif_rotated_image, load_image
+
+
+def test_exif_rotated_image_without_path(qapp):
+    img = exif_rotated_image()
+    assert img.isNull() is True
+
+
+def test_exif_rotated_image_not_a_file(qapp):
+    img = exif_rotated_image('foo')
+    assert img.isNull() is True
+
+
+@pytest.mark.parametrize('path,expected',
+                         [('test3x3.png', 'test3x3.png'),
+                          ('test3x3_orientation1.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation2.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation3.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation4.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation5.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation6.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation7.jpg', 'test3x3.jpg'),
+                          ('test3x3_orientation8.jpg', 'test3x3.jpg')])
+def test_exif_rotated_image(path, expected, qapp):
+    def get_fname(p):
+        root = os.path.dirname(__file__)
+        return os.path.join(root, '..', 'assets', p)
+
+    img = exif_rotated_image(get_fname(path))
+    assert img.isNull() is False
+    expected = QtGui.QImage(get_fname(expected))
+    assert expected.isNull() is False
+
+    # The JPEG format isn't pixel perfect, so we have to check whether
+    # pixels are approximately the same:
+    for x in range(3):
+        for y in range(3):
+            col_img = img.pixelColor(x, y).getRgb()
+            col_expected = expected.pixelColor(x, y).getRgb()
+            diff = [(col_img[i] - col_expected[i])**2 for i in range(4)]
+            assert math.sqrt(sum(diff)) < 3
 
 
 def test_load_image_loads_from_filename(view, imgfilename3x3):