Merge pull request #6270 from radarhere/samples_per_pixel

Adjust BITSPERSAMPLE to match SAMPLESPERPIXEL

Author: hugovk

Tests/images/tiff_wrong_bits_per_sample_3.tiff

@@ -92,17 +92,33 @@ def test_bigtiff(self):
             assert_image_equal_tofile(im, "Tests/images/hopper.tif")
 
     @pytest.mark.parametrize(
-        "file_name,mode,size,offset",
+        "file_name,mode,size,tile",
         [
-            ("tiff_wrong_bits_per_sample.tiff", "RGBA", (52, 53), 160),
-            ("tiff_wrong_bits_per_sample_2.tiff", "RGB", (16, 16), 8),
+            (
+                "tiff_wrong_bits_per_sample.tiff",
+                "RGBA",
+                (52, 53),
+                [("raw", (0, 0, 52, 53), 160, ("RGBA", 0, 1))],
+            ),
+            (
+                "tiff_wrong_bits_per_sample_2.tiff",
+                "RGB",
+                (16, 16),
+                [("raw", (0, 0, 16, 16), 8, ("RGB", 0, 1))],
+            ),
+            (
+                "tiff_wrong_bits_per_sample_3.tiff",
+                "RGBA",
+                (512, 256),
+                [("libtiff", (0, 0, 512, 256), 0, ("RGBA", "tiff_lzw", False, 48782))],
+            ),
         ],
     )
-    def test_wrong_bits_per_sample(self, file_name, mode, size, offset):
+    def test_wrong_bits_per_sample(self, file_name, mode, size, tile):
         with Image.open("Tests/images/" + file_name) as im:
             assert im.mode == mode
             assert im.size == size
-            assert im.tile == [("raw", (0, 0) + size, offset, (mode, 0, 1))]
+            assert im.tile == tile
             im.load()
 
     def test_set_legacy_api(self):

Tests/test_file_tiff.py

@@ -1355,19 +1355,19 @@ def _setup(self):
             bps_count = 1
         bps_count += len(extra_tuple)
         bps_actual_count = len(bps_tuple)
-        if bps_count < bps_actual_count:
+        samples_per_pixel = self.tag_v2.get(
+            SAMPLESPERPIXEL,
+            3 if self._compression == "tiff_jpeg" and photo in (2, 6) else 1,
+        )
+        if samples_per_pixel < bps_actual_count:
             # If a file has more values in bps_tuple than expected,
             # remove the excess.
-            bps_tuple = bps_tuple[:bps_count]
-        elif bps_count > bps_actual_count and bps_actual_count == 1:
+            bps_tuple = bps_tuple[:samples_per_pixel]
+        elif samples_per_pixel > bps_actual_count and bps_actual_count == 1:
             # If a file has only one value in bps_tuple, when it should have more,
             # presume it is the same number of bits for all of the samples.
-            bps_tuple = bps_tuple * bps_count
+            bps_tuple = bps_tuple * samples_per_pixel
 
-        samples_per_pixel = self.tag_v2.get(
-            SAMPLESPERPIXEL,
-            3 if self._compression == "tiff_jpeg" and photo in (2, 6) else 1,
-        )
         if len(bps_tuple) != samples_per_pixel:
             raise SyntaxError("unknown data organization")