Merge pull request #2883 from uploadcare/tiff-wrong-bitspersample

Fix count of BITSPERSAMPLE items in broken TIFF files

PIL/TiffImagePlugin.py

@@ -1186,12 +1186,23 @@ def _setup(self):
             # for more exotic images.
             sampleFormat = (1,)
 
+        bps_tuple = self.tag_v2.get(BITSPERSAMPLE, (1,))
+        extra_tuple = self.tag_v2.get(EXTRASAMPLES, ())
+        if photo in (2, 6, 8):  # RGB, YCbCr, LAB
+            bps_count = 3
+        elif photo == 5:  # CMYK
+            bps_count = 4
+        else:
+            bps_count = 1
+        bps_count += len(extra_tuple)
+        # Some files have only one value in bps_tuple,
+        # while should have more. Fix it
+        if bps_count > len(bps_tuple) and len(bps_tuple) == 1:
+            bps_tuple = bps_tuple * bps_count
+
         # mode: check photometric interpretation and bits per pixel
-        key = (
-            self.tag_v2.prefix, photo, sampleFormat, fillorder,
-            self.tag_v2.get(BITSPERSAMPLE, (1,)),
-            self.tag_v2.get(EXTRASAMPLES, ())
-            )
+        key = (self.tag_v2.prefix, photo, sampleFormat, fillorder,
+               bps_tuple, extra_tuple)
         if DEBUG:
             print("format key:", key)
         try:

Tests/test_file_tiff.py

@@ -59,6 +59,14 @@ def test_16bit_RGBa_tiff(self):
         self.assertEqual(im.tile, [('tiff_lzw', (0, 0, 100, 40), 50, 'RGBa;16B')])
         im.load()
 
+    def test_wrong_bits_per_sample(self):
+        im = Image.open("Tests/images/tiff_wrong_bits_per_sample.tiff")
+
+        self.assertEqual(im.mode, "RGBA")
+        self.assertEqual(im.size, (52, 53))
+        self.assertEqual(im.tile, [('raw', (0, 0, 52, 53), 160, ('RGBA', 0, 1))])
+        im.load()
+
     def test_gimp_tiff(self):
         # Read TIFF JPEG images from GIMP [@PIL168]