Merge pull request #1782 from radarhere/compression

Different frames may have different compression types

PIL/TiffImagePlugin.py

@@ -238,8 +238,8 @@ class IFDRational(Rational):
     as a fractions.Fraction(). Delegate as appropriate
 
     """
-    
-    __slots__ = ('_numerator', '_denominator', '_val') 
+
+    __slots__ = ('_numerator', '_denominator', '_val')
 
     def __init__(self, value, denominator=1):
         """
@@ -255,7 +255,7 @@ def __init__(self, value, denominator=1):
             self._numerator = value.numerator
             self._denominator = value.denominator
             self._val = value
-        
+
         if type(value) == IFDRational:
             self._denominator = value.denominator
             self._numerator = value.numerator
@@ -287,7 +287,7 @@ def denominator(a):
 
     def limit_rational(self, max_denominator):
         """
-        
+
         :param max_denominator: Integer, the maximum denominator value
         :returns: Tuple of (numerator, denominator)
         """
@@ -349,7 +349,7 @@ def delegate(self, *args):
     __floor__ = _delegate('__floor__')
     __round__ = _delegate('__round__')
 
-    
+
 
 class ImageFileDirectory_v2(collections.MutableMapping):
     """This class represents a TIFF tag directory.  To speed things up, we
@@ -991,6 +991,11 @@ def _decoder(self, rawmode, layer, tile=None):
 
         return args
 
+    def load(self):
+        if self.use_load_libtiff:
+            return self._load_libtiff()
+        return super(TiffImageFile, self).load()
+
     def _load_libtiff(self):
         """ Overload method triggered when we detect a compressed tiff
             Calls out to libtiff """
@@ -1136,6 +1141,7 @@ def _setup(self):
         # build tile descriptors
         x = y = l = 0
         self.tile = []
+        self.use_load_libtiff = False
         if STRIPOFFSETS in self.tag_v2:
             # striped image
             offsets = self.tag_v2[STRIPOFFSETS]
@@ -1158,10 +1164,9 @@ def _setup(self):
                 # function.
                 #
                 # Setup the one tile for the whole image, then
-                # replace the existing load function with our
-                # _load_libtiff function.
+                # use the _load_libtiff function.
 
-                self.load = self._load_libtiff
+                self.use_load_libtiff = True
 
                 # To be nice on memory footprint, if there's a
                 # file descriptor, use that instead of reading

Tests/test_file_tiff.py

@@ -378,6 +378,22 @@ def test_deprecation_warning_with_spaces(self):
         self.assertEqual(im.tag_v2[X_RESOLUTION], 36)
         self.assertEqual(im.tag_v2[Y_RESOLUTION], 72)
 
+    def test_multipage_compression(self):
+        im = Image.open('Tests/images/compression.tif')
+
+        im.seek(0)
+        self.assertEqual(im._compression,'tiff_ccitt')
+        self.assertEqual(im.size, (10, 10))
+
+        im.seek(1)
+        self.assertEqual(im._compression,'packbits')
+        self.assertEqual(im.size, (10, 10))
+        im.load()
+
+        im.seek(0)
+        self.assertEqual(im._compression,'tiff_ccitt')
+        self.assertEqual(im.size, (10, 10))
+        im.load()
 
 if __name__ == '__main__':
     unittest.main()