Merge pull request #3848 from radarhere/pa

Improved palette handling for LA and PA modes

Tests/test_file_im.py

@@ -48,7 +48,7 @@ class TestFileIm(PillowTestCase):
         im.seek(n_frames-1)
 
     def test_roundtrip(self):
-        for mode in ["RGB", "P"]:
+        for mode in ["RGB", "P", "PA"]:
             out = self.tempfile('temp.im')
             im = hopper(mode)
             im.save(out)

Tests/test_file_tiff.py

@@ -489,6 +489,16 @@ class TestFileTiff(PillowTestCase):
         self.assert_image_equal_tofile(im,
                                        "Tests/images/tiff_adobe_deflate.png")
 
+    def test_palette(self):
+        for mode in ["P", "PA"]:
+            outfile = self.tempfile("temp.tif")
+
+            im = hopper(mode)
+            im.save(outfile)
+
+            reloaded = Image.open(outfile)
+            self.assert_image_equal(im.convert("RGB"), reloaded.convert("RGB"))
+
     def test_tiff_save_all(self):
         import io
         import os

Tests/test_pickle.py

@@ -75,6 +75,15 @@ class TestPickle(PillowTestCase):
                                           protocol=protocol,
                                           test_file=test_file)
 
+    def test_pickle_pa_mode(self):
+        # Arrange
+        import pickle
+
+        # Act / Assert
+        for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
+            self.helper_pickle_string(pickle, protocol, mode="PA")
+            self.helper_pickle_file(pickle, protocol, mode="PA")
+
     def test_pickle_l_mode(self):
         # Arrange
         import pickle
@@ -84,6 +93,24 @@ class TestPickle(PillowTestCase):
             self.helper_pickle_string(pickle, protocol, mode="L")
             self.helper_pickle_file(pickle, protocol, mode="L")
 
+    def test_pickle_la_mode_with_palette(self):
+        # Arrange
+        import pickle
+        im = Image.open('Tests/images/hopper.jpg')
+        filename = self.tempfile('temp.pkl')
+        im = im.convert("PA")
+
+        # Act / Assert
+        for protocol in range(0, pickle.HIGHEST_PROTOCOL + 1):
+            im.mode = "LA"
+            with open(filename, 'wb') as f:
+                pickle.dump(im, f, protocol)
+            with open(filename, 'rb') as f:
+                loaded_im = pickle.load(f)
+
+            im.mode = "PA"
+            self.assertEqual(im, loaded_im)
+
     def test_cpickle_l_mode(self):
         # Arrange
         try:

docs/reference/Image.rst

@@ -210,9 +210,9 @@ Instances of the :py:class:`Image` class have the following attributes:
 
 .. py:attribute:: palette
 
-    Colour palette table, if any. If mode is “P”, this should be an instance of
+    Colour palette table, if any. If mode is "P" or "PA", this should be an
-    the :py:class:`~PIL.ImagePalette.ImagePalette` class. Otherwise, it should
+    instance of the :py:class:`~PIL.ImagePalette.ImagePalette` class.
-    be set to ``None``.
+    Otherwise, it should be set to ``None``.
 
     :type: :py:class:`~PIL.ImagePalette.ImagePalette` or ``None``
 

src/PIL/ImImagePlugin.py

@@ -71,6 +71,7 @@ OPEN = {
     "RYB3 image": ("RGB", "RYB;T"),
     # extensions
     "LA image": ("LA", "LA;L"),
+    "PA image": ("LA", "PA;L"),
     "RGBA image": ("RGBA", "RGBA;L"),
     "RGBX image": ("RGBX", "RGBX;L"),
     "CMYK image": ("CMYK", "CMYK;L"),
@@ -218,15 +219,16 @@ class ImImageFile(ImageFile.ImageFile):
                         linear = 0
                 else:
                     greyscale = 0
-            if self.mode == "L" or self.mode == "LA":
+            if self.mode in ["L", "LA", "P", "PA"]:
                 if greyscale:
                     if not linear:
                         self.lut = [i8(c) for c in palette[:256]]
                 else:
-                    if self.mode == "L":
+                    if self.mode in ["L", "P"]:
                         self.mode = self.rawmode = "P"
-                    elif self.mode == "LA":
+                    elif self.mode in ["LA", "PA"]:
-                        self.mode = self.rawmode = "PA"
+                        self.mode = "PA"
+                        self.rawmode = "PA;L"
                     self.palette = ImagePalette.raw("RGB;L", palette)
             elif self.mode == "RGB":
                 if not greyscale or not linear:
@@ -340,10 +342,10 @@ def _save(im, fp, filename):
         fp.write(("Name: %s\r\n" % filename).encode('ascii'))
     fp.write(("Image size (x*y): %d*%d\r\n" % im.size).encode('ascii'))
     fp.write(("File size (no of images): %d\r\n" % frames).encode('ascii'))
-    if im.mode == "P":
+    if im.mode in ["P", "PA"]:
         fp.write(b"Lut: 1\r\n")
     fp.write(b"\000" * (511-fp.tell()) + b"\032")
-    if im.mode == "P":
+    if im.mode in ["P", "PA"]:
         fp.write(im.im.getpalette("RGB", "RGB;L"))  # 768 bytes
     ImageFile._save(im, fp, [("raw", (0, 0)+im.size, 0, (rawmode, 0, -1))])
 

src/PIL/Image.py

@@ -715,7 +715,7 @@ class Image(object):
         self.mode = mode
         self._size = size
         self.im = core.new(mode, size)
-        if mode in ("L", "P") and palette:
+        if mode in ("L", "LA", "P", "PA") and palette:
             self.putpalette(palette)
         self.frombytes(data)
 

src/PIL/TiffImagePlugin.py

@@ -1357,7 +1357,7 @@ class TiffImageFile(ImageFile.ImageFile):
 
         # fixup palette descriptor
 
-        if self.mode == "P":
+        if self.mode in ["P", "PA"]:
             palette = [o8(b // 256) for b in self.tag_v2[COLORMAP]]
             self.palette = ImagePalette.raw("RGB;L", b"".join(palette))
 
@@ -1483,7 +1483,7 @@ def _save(im, fp, filename):
 
     ifd[PHOTOMETRIC_INTERPRETATION] = photo
 
-    if im.mode == "P":
+    if im.mode in ["P", "PA"]:
         lut = im.im.getpalette("RGB", "RGB;L")
         ifd[COLORMAP] = tuple(i8(v) * 256 for v in lut)
     # data orientation

src/_imaging.c

@@ -1588,7 +1588,7 @@ _putpalette(ImagingObject* self, PyObject* args)
 
     ImagingPaletteDelete(self->image->palette);
 
-    strcpy(self->image->mode, "P");
+    strcpy(self->image->mode, strlen(self->image->mode) == 2 ? "PA" : "P");
 
     self->image->palette = ImagingPaletteNew("RGB");