Merge pull request #2719 from wiredfool/issue_2278

Fixes for Issues #2278 and #2006, value error in exif/tiff ifd

PIL/TiffImagePlugin.py

@@ -550,11 +550,28 @@ class ImageFileDirectory_v2(collections.MutableMapping):
 
         dest = self._tags_v1 if legacy_api else self._tags_v2
 
-        if info.length == 1:
-            if legacy_api and self.tagtype[tag] in [5, 10]:
+        # Three branches:
+        # Spec'd length == 1, Actual length 1, store as element
+        # Spec'd length == 1, Actual > 1, Warn and truncate. Formerly barfed.
+        # No Spec, Actual length 1, Formerly (<4.2) returned a 1 element tuple.
+        # Don't mess with the legacy api, since it's frozen.
+        if ((info.length == 1) or 
+            (info.length is None and len(values) == 1 and not legacy_api)): 
+            # Don't mess with the legacy api, since it's frozen.
+            if legacy_api and self.tagtype[tag] in [5, 10]: # rationals
                 values = values,
-            dest[tag], = values
+            try:
+                dest[tag], = values
+            except ValueError:
+                # We've got a builtin tag with 1 expected entry
+                warnings.warn(
+                    "Metadata Warning, tag %s had too many entries: %s, expected 1" % (
+                        tag, len(values)))
+                dest[tag] = values[0]
+
         else:
+            # Spec'd length > 1 or undefined
+            # Unspec'd, and length > 1
             dest[tag] = values
 
     def __delitem__(self, tag):
@@ -1011,8 +1028,10 @@ class TiffImageFile(ImageFile.ImageFile):
             args = rawmode, ""
             if JPEGTABLES in self.tag_v2:
                 # Hack to handle abbreviated JPEG headers
-                # FIXME This will fail with more than one value
-                self.tile_prefix, = self.tag_v2[JPEGTABLES]
+                # Definition of JPEGTABLES is that the count
+                # is the number of bytes in the tables datastream
+                # so, it should always be 1 in our tag info
+                self.tile_prefix = self.tag_v2[JPEGTABLES]
         elif compression == "packbits":
             args = rawmode
         elif compression == "tiff_lzw":

PIL/TiffTags.py

@@ -23,7 +23,7 @@ from collections import namedtuple
 class TagInfo(namedtuple("_TagInfo", "value name type length enum")):
     __slots__ = []
 
-    def __new__(cls, value=None, name="unknown", type=None, length=0, enum=None):
+    def __new__(cls, value=None, name="unknown", type=None, length=None, enum=None):
         return super(TagInfo, cls).__new__(
             cls, value, name, type, length, enum or {})
 
@@ -142,6 +142,8 @@ TAGS_V2 = {
     341: ("SMaxSampleValue", DOUBLE, 0),
     342: ("TransferRange", SHORT, 6),
 
+    347: ("JPEGTables", UNDEFINED, 1),
+    
     # obsolete JPEG tags
     512: ("JPEGProc", SHORT, 1),
     513: ("JPEGInterchangeFormat", LONG, 1),
@@ -158,7 +160,10 @@ TAGS_V2 = {
     531: ("YCbCrPositioning", SHORT, 1),
     532: ("ReferenceBlackWhite", LONG, 0),
 
+    700: ('XMP', BYTE, 1),
+    
     33432: ("Copyright", ASCII, 1),
+    34377: ('PhotoshopInfo', BYTE, 1),
 
     # FIXME add more tags here
     34665: ("ExifIFD", SHORT, 1),
@@ -188,8 +193,8 @@ TAGS_V2 = {
 
     50741: ("MakerNoteSafety", SHORT, 1, {"Unsafe": 0, "Safe": 1}),
     50780: ("BestQualityScale", RATIONAL, 1),
-    50838: ("ImageJMetaDataByteCounts", LONG, 1),
-    50839: ("ImageJMetaData", UNDEFINED, 1)
+    50838: ("ImageJMetaDataByteCounts", LONG, 0), # Can be more than one 
+    50839: ("ImageJMetaData", UNDEFINED, 1)       # see Issue #2006
 }
 
 # Legacy Tags structure

Tests/test_file_tiff_metadata.py

@@ -56,7 +56,7 @@ class TestFileTiffMetadata(PillowTestCase):
         loaded = Image.open(f)
 
         self.assertEqual(loaded.tag[ImageJMetaDataByteCounts], (len(bindata),))
-        self.assertEqual(loaded.tag_v2[ImageJMetaDataByteCounts], len(bindata))
+        self.assertEqual(loaded.tag_v2[ImageJMetaDataByteCounts], (len(bindata),))
 
         self.assertEqual(loaded.tag[ImageJMetaData], bindata)
         self.assertEqual(loaded.tag_v2[ImageJMetaData], bindata)
@@ -69,6 +69,16 @@ class TestFileTiffMetadata(PillowTestCase):
         loaded_double = loaded.tag[tag_ids['YawAngle']][0]
         self.assertAlmostEqual(loaded_double, doubledata)
 
+        # check with 2 element ImageJMetaDataByteCounts, issue #2006
+        
+        info[ImageJMetaDataByteCounts] = (8, len(bindata) - 8)
+        img.save(f, tiffinfo=info)
+        loaded = Image.open(f)
+
+        self.assertEqual(loaded.tag[ImageJMetaDataByteCounts], (8, len(bindata) - 8))
+        self.assertEqual(loaded.tag_v2[ImageJMetaDataByteCounts], (8, len(bindata) - 8))
+
+
     def test_read_metadata(self):
         img = Image.open('Tests/images/hopper_g4.tif')
 
@@ -202,8 +212,8 @@ class TestFileTiffMetadata(PillowTestCase):
         im.save(out, tiffinfo=info, compression='raw')
 
         reloaded = Image.open(out)
-        self.assertEqual(0, reloaded.tag_v2[41988][0].numerator)
-        self.assertEqual(0, reloaded.tag_v2[41988][0].denominator)
+        self.assertEqual(0, reloaded.tag_v2[41988].numerator)
+        self.assertEqual(0, reloaded.tag_v2[41988].denominator)
 
     def test_expty_values(self):
         data = io.BytesIO(
@@ -220,6 +230,27 @@ class TestFileTiffMetadata(PillowTestCase):
             self.fail("Should not be struct value error there.")
         self.assertIn(33432, info)
 
+    def test_PhotoshopInfo(self):
+        im = Image.open('Tests/images/issue_2278.tif')
+
+        self.assertIsInstance(im.tag_v2[34377], bytes)
+        out = self.tempfile('temp.tiff')
+        im.save(out)
+        reloaded = Image.open(out)
+        self.assertIsInstance(reloaded.tag_v2[34377], bytes)
+
+    def test_too_many_entries(self):
+        ifd = TiffImagePlugin.ImageFileDirectory_v2()
+
+        #    277: ("SamplesPerPixel", SHORT, 1),
+        ifd._tagdata[277] = struct.pack('hh', 4,4)
+        ifd.tagtype[277] = TiffTags.SHORT
+
+        try:
+            self.assert_warning(UserWarning, lambda: ifd[277])
+        except ValueError:
+            self.fail("Invalid Metadata count should not cause a Value Error.")
+
 
 if __name__ == '__main__':
     unittest.main()

docs/releasenotes/4.3.0.rst

@@ -46,6 +46,22 @@ This release contains several performance improvements:
   using a recent version of libjpeg-turbo.
 
 
+TIFF Metadata Changes
+=====================
+
+* TIFF tags with unknown type/quantity now default to being bare
+  values if they are 1 element, where previously they would be a
+  single element tuple. This is only with the new api, not the legacy
+  api. This normalizes the handling of fields, so that the metadata
+  with inferred or image specified counts are handled the same as
+  metadata with count specified in the TIFF spec. 
+* The ``PhotoshopInfo``, ``XMP``, and ``JPEGTables`` tags now have a
+  defined type (bytes) and a count of 1.
+* The ``ImageJMetaDataByteCounts`` tag now has an arbitrary number of
+  items, as there can be multiple items, one for UTF-8, and one for
+  UTF-16.
+
+
 Core Image API Changes
 ======================