Fix color management by keeping ICC color profiles and EXIF data in addition

tests/test_wand.py

@@ -158,6 +158,38 @@ def test_save_as_jpeg_progressive(self):
 
  self.assertTrue(PILImage.open(image.f).info["progressive"])
 
+ def test_save_as_jpeg_with_icc_profile(self):
+ images = ["colorchecker_sRGB.jpg", "colorchecker_ECI_RGB_v2.jpg"]
+ for img_name in images:
+ with open(f"tests/images/{img_name}", "rb") as f:
+ image = WandImage.open(JPEGImageFile(f))
+
+ icc_profile = image.get_wand_image().profiles["ICC"]
+ self.assertIsNotNone(icc_profile)
+
+ buffer = io.BytesIO()
+ image.save_as_jpeg(buffer)
+ buffer.seek(0)
+
+ saved = WandImage.open(JPEGImageFile(buffer))
+ saved_icc_profile = saved.get_wand_image().profiles["ICC"]
+ self.assertEqual(saved_icc_profile, icc_profile)
+
+ def test_save_as_jpeg_with_exif(self):
+ with open("tests/images/colorchecker_sRGB.jpg", "rb") as f:
+ image = WandImage.open(JPEGImageFile(f))
+
+ exif_datetime = image.get_wand_image().metadata.get("exif:DateTime")
+ self.assertIsNotNone(exif_datetime)
+
+ buffer = io.BytesIO()
+ image.save_as_jpeg(buffer)
+ buffer.seek(0)
+
+ saved = WandImage.open(JPEGImageFile(buffer))
+ saved_exif_datetime = saved.get_wand_image().metadata.get("exif:DateTime")
+ self.assertEqual(saved_exif_datetime, exif_datetime)
+
  def test_save_as_png(self):
  output = io.BytesIO()
  return_value = self.image.save_as_png(output)
@@ -358,6 +390,24 @@ def test_save_webp_lossless(self):
  break
  self.assertTrue(identical)
 
+ @unittest.skipIf(no_webp_support, "ImageMagick was built without WebP support")
+ def test_save_as_webp_with_icc_profile(self):
+ images = ["colorchecker_sRGB.jpg", "colorchecker_ECI_RGB_v2.jpg"]
+ for img_name in images:
+ with open(f"tests/images/{img_name}", "rb") as f:
+ image = WandImage.open(JPEGImageFile(f))
+
+ icc_profile = image.get_wand_image().profiles["ICC"]
+ self.assertIsNotNone(icc_profile)
+
+ buffer = io.BytesIO()
+ image.save_as_webp(buffer)
+ buffer.seek(0)
+
+ saved = WandImage.open(WebPImageFile(buffer))
+ saved_icc_profile = saved.get_wand_image().profiles["ICC"]
+ self.assertEqual(saved_icc_profile, icc_profile)
+
 
 class TestWandImageWithOptimizers(unittest.TestCase):
  def setUp(self):

willow/plugins/wand.py

@@ -146,6 +146,12 @@ def set_background_color_rgb(self, color):
 
  return clone
 
+ def get_icc_profile(self):
+ return self.image.metadata.get("icc-profile")
+
+ def get_exif_data(self):
+ return self.image.metadata.get("exif")
+
  @Image.operation
  def save_as_jpeg(
  self,
@@ -164,8 +170,18 @@ def save_as_jpeg(
  :param apply_optimizers: controls whether to run any configured optimizer libraries
  :return: JPEGImageFile
  """
- with self.image.convert("pjpeg" if progressive else "jpeg") as converted:
+ with self.image.clone() as converted:
+ converted.format = "pjpeg" if progressive else "jpeg"
  converted.compression_quality = quality
+
+ icc_profile = self.get_icc_profile()
+ if icc_profile is not None:
+ converted.profiles["icc"] = icc_profile
+
+ exif_data = self.get_exif_data()
+ if exif_data is not None:
+ converted.profiles["exif"] = exif_data
+
  converted.save(file=f)
 
  if apply_optimizers:
@@ -215,7 +231,9 @@ def save_as_webp(
  Note that when lossless=True, this will be ignored.
  :return: WebPImageFile
  """
- with self.image.convert("webp") as converted:
+ with self.image.clone() as converted:
+ converted.format = "webp"
+
  if lossless:
  library = _wand_api().library
  library.MagickSetOption.argtypes = [c_void_p, c_char_p, c_char_p]
@@ -226,7 +244,13 @@ def save_as_webp(
  )
  else:
  converted.compression_quality = quality
+
+ icc_profile = self.get_icc_profile()
+ if icc_profile is not None:
+ converted.profiles["icc"] = icc_profile
+
  converted.save(file=f)
+
  if not lossless and apply_optimizers:
  self.optimize(f, "webp")
  return WebPImageFile(f)