Merge branch 'jpeg-orientation'

README.rst

@@ -58,6 +58,7 @@ Changelog
 
   * Python 2.7 support dropped
   * Allow to cancel an optimization using Ctrl+C (NOTE: this may not work on Windows)
+  * Honor JPEG orientation EXIF tag
 
 * **1.0.0:**
 

scripts/lsexif.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+
+import sys
+
+from PIL import Image
+from PIL.ExifTags import TAGS
+
+
+def print_exif(input_path):
+    image = Image.open(input_path)
+    exif = image.getexif()
+
+    print("+-- %s" % input_path)
+    for key, value in exif.items():
+        print("    +-- [%i] %s: %s" % (key, TAGS[key], value))
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        print("USAGE:")
+        print(
+            "  ./scripts/lsexif.py <image.jpg> [image2.jpg ...]"
+        )
+        sys.exit(1)
+
+    for input_path in sys.argv[1:]:
+        print_exif(input_path)

test/test_image_encoders_jpeg.py

@@ -0,0 +1,39 @@
+import pytest
+
+from yoga.image.encoders import jpeg
+
+
+class Test_open_jpeg(object):
+    @pytest.mark.parametrize(
+        "image_path",
+        [
+            "test/images/orientation/no-metadata.jpg",
+            "test/images/orientation/1-rotation-0.jpg",
+            "test/images/orientation/2-flip-horizontal.jpg",
+            "test/images/orientation/3-rotation-180.jpg",
+            "test/images/orientation/4-flip-vertical.jpg",
+            "test/images/orientation/5-rotation-270-flip-horizontal.jpg",
+            "test/images/orientation/6-rotation-270.jpg",
+            "test/images/orientation/7-rotation-90-flip-horizontal.jpg",
+            "test/images/orientation/8-rotation-90.jpg",
+        ],
+    )
+    def test_jpeg_orientation(self, image_path):
+        with open(image_path, "rb") as image_file:
+            image = jpeg.open_jpeg(image_file)
+
+            # Test image size
+            assert image.width == 256
+            assert image.height == 341
+
+            # Check if the red square is at top-left corner
+            r1, g1, b1 = image.getpixel((8, 8))
+            assert r1 > 250 and g1 < 5 and b1 < 5  # ~red
+
+            # Check if the green square is at top-right corner
+            r2, g2, b2 = image.getpixel((255 - 8, 8))
+            assert r2 < 5 and g2 > 250 and b2 < 5  # ~lime
+
+            # Check if the blue square is at bottom-right corner
+            r3, g3, b3 = image.getpixel((255 - 8, 340 - 8))
+            assert r3 < 5 and g3 < 5 and b3 > 250  # ~blue

yoga/image/__init__.py

@@ -169,6 +169,7 @@ API
 from PIL import Image
 
 from .encoders.jpeg import optimize_jpeg
+from .encoders.jpeg import open_jpeg
 from .encoders.png import optimize_png
 from .encoders.webp import optimize_lossy_webp
 from .encoders.webp_lossless import optimize_lossless_webp
@@ -195,8 +196,19 @@ def optimize(input_file, output_file, options={}, verbose=False, quiet=False):
     else:
         raise ValueError("Unsupported parameter type for 'input_file'")
 
+    # Determine the input image format
+    try:
+        input_format = helpers.guess_image_format(image_file.read())
+    except ValueError:
+        input_format = None
+    finally:
+        image_file.seek(0)  # to allow PIL.Image to read the file
+
     # Open the image with Pillow
-    image = Image.open(image_file)
+    if input_format == "jpeg":
+        image = open_jpeg(image_file)
+    else:
+        image = Image.open(image_file)
 
     # Resize image if requested
     if options["resize"] != "orig":
@@ -204,8 +216,9 @@ def optimize(input_file, output_file, options={}, verbose=False, quiet=False):
 
     # Output format
     if options["output_format"] == "orig":
-        image_file.seek(0)  # PIL.Image already read the file
-        output_format = helpers.guess_image_format(image_file.read())
+        if input_format is None:
+            raise ValueError("Unsupported image format")
+        output_format = input_format
     elif options["output_format"] == "auto":
         if helpers.image_have_alpha(image, options["opacity_threshold"]):
             output_format = "png"

yoga/image/encoders/jpeg.py

@@ -1,4 +1,5 @@
 import pyguetzli
+from PIL import Image
 
 
 def is_jpeg(file_bytes):
@@ -32,3 +33,34 @@ def optimize_jpeg(image, quality):
     if not 0.00 <= quality <= 1.00:
         raise ValueError("JPEG quality value must be between 0.00 and 1.00")
     return pyguetzli.process_pil_image(image, int(quality * 100))
+
+
+def open_jpeg(image_file):
+    """Open JPEG file.
+
+    This function also handles JPEG Orientation EXIF.
+
+    :param file-like image_file: the image file.
+    :rtype: PIL.Image
+    """
+    EXIF_TAG_ORIENTATION = 274
+    ORIENTATION_OPERATIONS = {
+        1: [],
+        2: [Image.FLIP_LEFT_RIGHT],
+        3: [Image.ROTATE_180],
+        4: [Image.FLIP_TOP_BOTTOM],
+        5: [Image.FLIP_LEFT_RIGHT, Image.ROTATE_90],
+        6: [Image.ROTATE_270],
+        7: [Image.FLIP_LEFT_RIGHT, Image.ROTATE_270],
+        8: [Image.ROTATE_90],
+    }
+
+    image = Image.open(image_file)
+    exif = image.getexif()
+
+    if EXIF_TAG_ORIENTATION in exif:
+        orientation = exif[EXIF_TAG_ORIENTATION]
+        for operation in ORIENTATION_OPERATIONS[orientation]:
+            image = image.transpose(operation)
+
+    return image