Viewing file:  ImageSequence.py (2.14 KB) -rw-r--r--
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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
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