diff --git a/PIL/GifImagePlugin.py b/PIL/GifImagePlugin.py index c53a61c94..7eeaae646 100644 --- a/PIL/GifImagePlugin.py +++ b/PIL/GifImagePlugin.py @@ -99,6 +99,8 @@ class GifImageFile(ImageFile.ImageFile): self.dispose_extent = [0, 0, 0, 0] #x0, y0, x1, y1 self.__frame = -1 self.__fp.seek(self.__rewind) + self._prev_im = None + self.disposal_method = 0 if frame != self.__frame + 1: raise ValueError("cannot seek to frame %d" % frame) @@ -120,7 +122,6 @@ class GifImageFile(ImageFile.ImageFile): from copy import copy self.palette = copy(self.global_palette) - disposal_method = 0 while True: s = self.fp.read(1) @@ -143,8 +144,8 @@ class GifImageFile(ImageFile.ImageFile): self.info["duration"] = i16(block[1:3]) * 10 # disposal method - find the value of bits 4 - 6 - disposal_method = 0b00011100 & flags - disposal_method = disposal_method >> 2 + self.disposal_method = 0b00011100 & flags + self.disposal_method = self.disposal_method >> 2 elif i8(s) == 255: # # application extension @@ -190,10 +191,10 @@ class GifImageFile(ImageFile.ImageFile): # raise IOError, "illegal GIF tag `%x`" % i8(s) try: - if disposal_method < 2: + if self.disposal_method < 2: # do not dispose or none specified self.dispose = None - elif disposal_method == 2: + elif self.disposal_method == 2: # replace with background colour self.dispose = Image.core.fill("P", self.size, self.info["background"]) @@ -220,6 +221,18 @@ class GifImageFile(ImageFile.ImageFile): def tell(self): return self.__frame + def load_end(self): + ImageFile.ImageFile.load_end(self) + + # if the disposal method is 'do not dispose', transparent + # pixels should show the content of the previous frame + if self._prev_im and self.disposal_method == 1: + # we do this by pasting the updated area onto the previous + # frame which we then use as the current image content + updated = self.im.crop(self.dispose_extent) + self._prev_im.paste(updated, self.dispose_extent, updated.convert('RGBA')) + self.im = self._prev_im + self._prev_im = self.im.copy() # -------------------------------------------------------------------- # Write GIF files