Add tests for opening 2-5 layer uint16 greyscale TIFFs.

Tests/test_file_tiff.py

@@ -450,6 +450,19 @@ class TestFileTiff(PillowTestCase):
         # Should not raise UnicodeDecodeError or anything else
         im.save(outfile)
 
+    def test_open_tiff_uint16_multiband(self):
+        """Test opening multiband TIFFs and reading all channels."""
+        base_value = 4660
+        for i in range(2, 6):
+            infile = "Tests/images/uint16_{}_{}.tif".format(i, base_value)
+            im = Image.open(infile)
+            im.load()
+            pixel = [base_value + j for j in range(0, i)]
+            actual_pixel = im.getpixel((0,0))
+            if type(actual_pixel) is int:
+                actual_pixel = [actual_pixel]
+            self.assertEqual(actual_pixel, pixel)
+
 if __name__ == '__main__':
     unittest.main()