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# | |
# The Python Imaging Library. | |
# $Id$ | |
# | |
# sequence support classes | |
# | |
# history: | |
# 1997-02-20 fl Created | |
# | |
# Copyright (c) 1997 by Secret Labs AB. | |
# Copyright (c) 1997 by Fredrik Lundh. | |
# | |
# See the README file for information on usage and redistribution. | |
# | |
## | |
from __future__ import annotations | |
from typing import Callable | |
from . import Image | |
class Iterator: | |
""" | |
This class implements an iterator object that can be used to loop | |
over an image sequence. | |
You can use the ``[]`` operator to access elements by index. This operator | |
will raise an :py:exc:`IndexError` if you try to access a nonexistent | |
frame. | |
:param im: An image object. | |
""" | |
def __init__(self, im: Image.Image): | |
if not hasattr(im, "seek"): | |
msg = "im must have seek method" | |
raise AttributeError(msg) | |
self.im = im | |
self.position = getattr(self.im, "_min_frame", 0) | |
def __getitem__(self, ix: int) -> Image.Image: | |
try: | |
self.im.seek(ix) | |
return self.im | |
except EOFError as e: | |
msg = "end of sequence" | |
raise IndexError(msg) from e | |
def __iter__(self) -> Iterator: | |
return self | |
def __next__(self) -> Image.Image: | |
try: | |
self.im.seek(self.position) | |
self.position += 1 | |
return self.im | |
except EOFError as e: | |
msg = "end of sequence" | |
raise StopIteration(msg) from e | |
def all_frames( | |
im: Image.Image | list[Image.Image], | |
func: Callable[[Image.Image], Image.Image] | None = None, | |
) -> list[Image.Image]: | |
""" | |
Applies a given function to all frames in an image or a list of images. | |
The frames are returned as a list of separate images. | |
:param im: An image, or a list of images. | |
:param func: The function to apply to all of the image frames. | |
:returns: A list of images. | |
""" | |
if not isinstance(im, list): | |
im = [im] | |
ims = [] | |
for imSequence in im: | |
current = imSequence.tell() | |
ims += [im_frame.copy() for im_frame in Iterator(imSequence)] | |
imSequence.seek(current) | |
return [func(im) for im in ims] if func else ims | |