Merge pull request #980 from wiredfool/pr_938

4 bit TIFF support

PIL/TiffImagePlugin.py

@@ -149,6 +149,7 @@ OPEN_INFO = {
     (II, 0, 1, 2, (8,), ()): ("L", "L;IR"),
     (II, 0, 3, 1, (32,), ()): ("F", "F;32F"),
     (II, 1, 1, 1, (1,), ()): ("1", "1"),
+    (II, 1, 1, 1, (4,), ()): ("L", "L;4"),
     (II, 1, 1, 2, (1,), ()): ("1", "1;R"),
     (II, 1, 1, 1, (8,), ()): ("L", "L"),
     (II, 1, 1, 1, (8, 8), (2,)): ("LA", "LA"),
@@ -449,10 +450,10 @@ class ImageFileDirectory(collections.MutableMapping):
             if size > 4:
                 here = fp.tell()
                 if Image.DEBUG:
-                    print ("Tag Location: %s" %here)
+                    print("Tag Location: %s" % here)
                 fp.seek(i32(ifd, 8))
                 if Image.DEBUG:
-                    print ("Data Location: %s" %fp.tell())
+                    print("Data Location: %s" % fp.tell())
                 data = ImageFile._safe_read(fp, size)
                 fp.seek(here)
             else:
@@ -659,14 +660,14 @@ class TiffImageFile(ImageFile.ImageFile):
             if not self.__next:
                 raise EOFError("no more images in TIFF file")
             if Image.DEBUG:
-                print("Seeking to frame %s, on frame %s, __next %s, location: %s"%
+                print("Seeking to frame %s, on frame %s, __next %s, location: %s" %
                       (frame, self.__frame, self.__next, self.fp.tell()))
             # reset python3 buffered io handle in case fp
             # was passed to libtiff, invalidating the buffer
             self.fp.tell()
             self.fp.seek(self.__next)
             if Image.DEBUG:
-                print("Loading tags, location: %s"%self.fp.tell())
+                print("Loading tags, location: %s" % self.fp.tell())
             self.tag.load(self.fp)
             self.__next = self.tag.next
             self.__frame += 1

Tests/test_file_libtiff.py

@@ -342,6 +342,24 @@ class TestFileLibTiff(LibTiffTestCase):
         im.load()
         self.assertFalse(im.tag.next)
 
+    def test_4bit(self):
+        # Arrange
+        test_file = "Tests/images/hopper_gray_4bpp.tif"
+        original = hopper("L")
+
+        # Act
+        TiffImagePlugin.READ_LIBTIFF = True
+        im = Image.open(test_file)
+        TiffImagePlugin.READ_LIBTIFF = False
+
+        # Assert
+        self.assertEqual(im.size, (128, 128))
+        self.assertEqual(im.mode, "L")
+        self.assert_image_similar(im, original, 7.3)
+
+
+
+
 if __name__ == '__main__':
     unittest.main()
 

Tests/test_file_tiff.py

@@ -144,28 +144,27 @@ class TestFileTiff(PillowTestCase):
     def test_multipage(self):
         # issue #862
         im = Image.open('Tests/images/multipage.tiff')
-        # file is a multipage tiff,  10x10 green, 10x10 red, 20x20 blue
+        # file is a multipage tiff: 10x10 green, 10x10 red, 20x20 blue
 
         im.seek(0)
-        self.assertEqual(im.size, (10,10))
+        self.assertEqual(im.size, (10, 10))
-        self.assertEqual(im.convert('RGB').getpixel((0,0)), (0,128,0))
+        self.assertEqual(im.convert('RGB').getpixel((0, 0)), (0, 128, 0))
 
         im.seek(1)
         im.load()
-        self.assertEqual(im.size, (10,10))
+        self.assertEqual(im.size, (10, 10))
-        self.assertEqual(im.convert('RGB').getpixel((0,0)), (255,0,0))
+        self.assertEqual(im.convert('RGB').getpixel((0, 0)), (255, 0, 0))
 
         im.seek(2)
         im.load()
-        self.assertEqual(im.size, (20,20))
+        self.assertEqual(im.size, (20, 20))
-        self.assertEqual(im.convert('RGB').getpixel((0,0)), (0,0,255))
+        self.assertEqual(im.convert('RGB').getpixel((0, 0)), (0, 0, 255))
 
     def test_multipage_last_frame(self):
         im = Image.open('Tests/images/multipage-lastframe.tif')
         im.load()
-        self.assertEqual(im.size, (20,20))
+        self.assertEqual(im.size, (20, 20))
-        self.assertEqual(im.convert('RGB').getpixel((0,0)), (0,0,255))
+        self.assertEqual(im.convert('RGB').getpixel((0, 0)), (0, 0, 255))
-
 
     def test___str__(self):
         # Arrange
@@ -199,7 +198,6 @@ class TestFileTiff(PillowTestCase):
 
     def test_load_byte(self):
         # Arrange
-        from PIL import TiffImagePlugin
         ifd = TiffImagePlugin.ImageFileDirectory()
         data = b"abc"
 
@@ -211,7 +209,6 @@ class TestFileTiff(PillowTestCase):
 
     def test_load_string(self):
         # Arrange
-        from PIL import TiffImagePlugin
         ifd = TiffImagePlugin.ImageFileDirectory()
         data = b"abc\0"
 
@@ -223,7 +220,6 @@ class TestFileTiff(PillowTestCase):
 
     def test_load_float(self):
         # Arrange
-        from PIL import TiffImagePlugin
         ifd = TiffImagePlugin.ImageFileDirectory()
         data = b"abcdabcd"
 
@@ -235,7 +231,6 @@ class TestFileTiff(PillowTestCase):
 
     def test_load_double(self):
         # Arrange
-        from PIL import TiffImagePlugin
         ifd = TiffImagePlugin.ImageFileDirectory()
         data = b"abcdefghabcdefgh"
 
@@ -298,6 +293,19 @@ class TestFileTiff(PillowTestCase):
         # Assert
         self.assertEqual(ret, [0, 1])
 
+    def test_4bit(self):
+        # Arrange
+        test_file = "Tests/images/hopper_gray_4bpp.tif"
+        original = hopper("L")
+
+        # Act
+        im = Image.open(test_file)
+
+        # Assert
+        self.assertEqual(im.size, (128, 128))
+        self.assertEqual(im.mode, "L")
+        self.assert_image_similar(im, original, 7.3)
+
 
     def test_page_number_x_0(self):
         # Issue 973