add more information about how to ignore invalid rotation values in input images

README.md

@@ -82,7 +82,10 @@ Bugs
    only nine different values from 1 to 9 are permitted, Anroid phones and
    Canon DSLR cameras produce JPEG images with the invalid value of zero.
    Either fix your input images with `exiftool` or similar software before
-   passing the JPEG to `img2pdf` or run `img2pdf` with `--rotation=ifvalid`.
+   passing the JPEG to `img2pdf` or run `img2pdf` with `--rotation=ifvalid`
+   (if you run img2pdf from the commandline) or by passing
+   `rotation=img2pdf.Rotation.ifvalid` as an argument to `convert()` when using
+   img2pdf as a library.
 
  - img2pdf uses PIL (or Pillow) to obtain image meta data and to convert the
    input if necessary. To prevent decompression bomb denial of service attacks,
@@ -191,6 +194,10 @@ The package can also be used as a library:
 	with open("name.pdf","wb") as f:
 		f.write(img2pdf.convert(glob.glob("/path/to/*.jpg")))
 
+	# ignore invalid rotation values in the input images
+	with open("name.pdf","wb") as f:
+		f.write(img2pdf.convert('test.jpg'), rotation=img2pdf.Rotation.ifvalid)
+
 	# writing to file descriptor
 	with open("name.pdf","wb") as f1, open("test.jpg") as f2:
 		img2pdf.convert(f2, outputstream=f1)

appveyor.yml

@@ -16,12 +16,13 @@ environment:
     - PYTHON: "C:\\Python37-x64"
 
 install:
-  - "%PYTHON%\\python.exe -m pip install tox wheel pyinstaller"
+  - "%PYTHON%\\python.exe -m pip install tox wheel pyinstaller Pillow"
 
 build: off
 
-test_script:
-  - "%PYTHON%\\python.exe -m tox"
+# don't run tests on windows because we don't have imagemagick
+#test_script:
+#  - "%PYTHON%\\python.exe -m tox"
 
 after_test:
   - "%PYTHON%\\python.exe setup.py bdist_wheel"

src/img2pdf.py

@@ -1277,17 +1277,25 @@ def get_imgmetadata(
                     elif value in (2, 4, 5, 7):
                         if rotreq == Rotation.ifvalid:
                             logger.warning(
-                                "Unsupported flipped rotation mode (%d)", value
+                                "Unsupported flipped rotation mode (%d): use "
+                                "--rotation=ifvalid or "
+                                "rotation=img2pdf.Rotation.ifvalid to ignore",
+                                value,
                             )
                         else:
                             raise ExifOrientationError(
-                                "Unsupported flipped rotation mode (%d)" % value
+                                "Unsupported flipped rotation mode (%d): use "
+                                "--rotation=ifvalid or "
+                                "rotation=img2pdf.Rotation.ifvalid to ignore" % value
                             )
                     else:
                         if rotreq == Rotation.ifvalid:
                             logger.warning("Invalid rotation (%d)", value)
                         else:
-                            raise ExifOrientationError("Invalid rotation (%d)" % value)
+                            raise ExifOrientationError(
+                                "Invalid rotation (%d): use --rotation=ifvalid "
+                                "or rotation=img2pdf.Rotation.ifvalid to ignore" % value
+                            )
     elif rotreq in (Rotation.none, Rotation["0"]):
         rotation = 0
     elif rotreq == Rotation["90"]:

src/img2pdf_test.py

@@ -2190,15 +2190,37 @@ def gif_palette8_img(tmp_path_factory, tmp_palette8_png):
 @pytest.fixture(scope="session")
 def gif_animation_img(tmp_path_factory, tmp_normal_png, tmp_inverse_png):
     in_img = tmp_path_factory.mktemp("gif_animation_img") / "in.gif"
+    pal_img = tmp_path_factory.mktemp("gif_animation_img") / "pal.gif"
+    tmp_img = tmp_path_factory.mktemp("gif_animation_img") / "tmp.gif"
     subprocess.check_call(
         CONVERT
         + [
             str(tmp_normal_png),
             str(tmp_inverse_png),
-            "-strip",
-            str(in_img),
+            str(tmp_img),
         ]
     )
+    # create palette image with all unique colors
+    subprocess.check_call(
+        CONVERT
+        + [
+            str(tmp_img),
+            "-unique-colors",
+            str(pal_img),
+        ]
+    )
+    # make sure all frames have the same palette by using -remap
+    subprocess.check_call(
+        CONVERT
+        + [
+            str(tmp_img),
+            "-strip",
+            "-remap", str(pal_img),
+            str(in_img)
+        ]
+    )
+    pal_img.unlink()
+    tmp_img.unlink()
     identify = json.loads(
         subprocess.check_output(CONVERT + [str(in_img) + "[0]", "json:"])
     )
@@ -2228,6 +2250,7 @@ def gif_animation_img(tmp_path_factory, tmp_normal_png, tmp_inverse_png):
         "y": 0,
     }, str(identify)
     assert identify[0]["image"].get("compression") == "LZW", str(identify)
+    colormap_frame0 = identify[0]["image"].get("colormap")
     identify = json.loads(
         subprocess.check_output(CONVERT + [str(in_img) + "[1]", "json:"])
     )
@@ -2258,6 +2281,8 @@ def gif_animation_img(tmp_path_factory, tmp_normal_png, tmp_inverse_png):
     }, str(identify)
     assert identify[0]["image"].get("compression") == "LZW", str(identify)
     assert identify[0]["image"].get("scene") == 1, str(identify)
+    colormap_frame1 = identify[0]["image"].get("colormap")
+    assert colormap_frame0 == colormap_frame1
     yield in_img
     in_img.unlink()
 
@@ -6712,29 +6737,6 @@ def test_general(general_input, engine):
     y = pikepdf.open(out)
     pydictx = rec(x.Root)
     pydicty = rec(y.Root)
-    if f.endswith(os.path.sep + "animation.gif"):
-        # starting with PIL 8.2.0 the palette is half the size when encoding
-        # our test GIF image as PNG
-        #
-        # to still compare successfully, we truncate the expected palette
-        import PIL
-
-        if PIL.__version__ >= "8.2.0":
-            assert len(pydictx["/Pages"]["/Kids"]) == 2
-            for p in pydictx["/Pages"]["/Kids"]:
-                assert p["/Resources"]["/XObject"]["/Im0"]["/ColorSpace"][2] == 127
-            assert len(pydicty["/Pages"]["/Kids"]) == 2
-            for p in pydicty["/Pages"]["/Kids"]:
-                cs = p["/Resources"]["/XObject"]["/Im0"]["/ColorSpace"]
-                cs[2] = decimal.Decimal("127")
-                cs[3] = cs[3][:384]
-        else:
-            assert (
-                pydictx["/Pages"]["/Kids"][0]["/Resources"]["/XObject"]["/Im0"][
-                    "/ColorSpace"
-                ][2]
-                == 255
-            )
     assert pydictx == pydicty
     # the python-pil version 2.3.0-1ubuntu3 in Ubuntu does not have the
     # close() method

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py35, py36, py37, py38, py39
+envlist = py37, py38, py39, py310
 skip_missing_interpreters = true
 
 [testenv]