我有一系列的图片,我想从中创建一个视频。理想情况下,我可以为每帧指定帧持续时间,但固定的帧速率也可以。我在wxPython中这样做,所以我可以渲染到wxDC或我可以将图像保存到文件,如PNG。是否有一个Python库,将允许我创建一个视频(AVI, MPG等)或一个动画GIF从这些帧?

编辑:我已经尝试过PIL,它似乎不起作用。有人能用这个结论来纠正我吗?这个链接似乎支持我关于PIL的结论:http://www.somethinkodd.com/oddthinking/2005/12/06/python-imaging-library-pil-and-animated-gifs/


当前回答

from PIL import Image
import glob  #use it if you want to read all of the certain file type in the directory
imgs=[]
for i in range(596,691): 
    imgs.append("snap"+str(i)+'.png')
    print("scanned the image identified with",i)  

标识不同文件名的索引的起始值和结束值+1

imgs = glob.glob("*.png") #do this if you want to read all files ending with .png

我的文件是:snap596.png, snap597.png ......snap690.png

frames = []
for i in imgs:
    new_frame = Image.open(i)
    frames.append(new_frame)

保存到一个GIF文件,永远循环

frames[0].save('fire3_PIL.gif', format='GIF',
    append_images=frames[1:],
    save_all=True,
    duration=300, loop=0)

我发现闪烁的问题与imageio和这个方法固定。

其他回答

要创建视频,你可以使用opencv,

#load your frames
frames = ...
#create a video writer
writer = cvCreateVideoWriter(filename, -1, fps, frame_size, is_color=1)
#and write your frames in a loop if you want
cvWriteFrame(writer, frames[i])

就像沃伦去年说的,这是一个老问题。由于人们似乎仍然在浏览页面,我想将他们重定向到一个更现代的解决方案。就像blakev说的,github上有一个枕头的例子。

 import ImageSequence
 import Image
 import gifmaker
 sequence = []

 im = Image.open(....)

 # im is your original image
 frames = [frame.copy() for frame in ImageSequence.Iterator(im)]

 # write GIF animation
 fp = open("out.gif", "wb")
 gifmaker.makedelta(fp, frames)
 fp.close()

注意:这个例子已经过时了(gifmaker不是一个可导入的模块,只是一个脚本)。Pillow有一个GifImagePlugin(其源代码在GitHub上),但ImageSequence上的文档似乎表明有限的支持(只读)

安装

pip install imageio-ffmpeg
pip install imageio

Code

import imageio
images = []
for filename in filenames:
    images.append(imageio.imread(filename))
imageio.mimsave('movie.mp4', images)

当保存为mp4而不是gif时,质量提高,大小从8Mb减少到80Kb

下面是如何使用PIL (install with: pip install Pillow):

import glob
import contextlib
from PIL import Image

# filepaths
fp_in = "/path/to/image_*.png"
fp_out = "/path/to/image.gif"

# use exit stack to automatically close opened images
with contextlib.ExitStack() as stack:

    # lazily load images
    imgs = (stack.enter_context(Image.open(f))
            for f in sorted(glob.glob(fp_in)))

    # extract  first image from iterator
    img = next(imgs)

    # https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html#gif
    img.save(fp=fp_out, format='GIF', append_images=imgs,
             save_all=True, duration=200, loop=0)

查看文档:https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html#gif

一个制作动图的简单函数:

import imageio
import pathlib
from datetime import datetime


def make_gif(image_directory: pathlib.Path, frames_per_second: float, **kwargs):
    """
    Makes a .gif which shows many images at a given frame rate.
    All images should be in order (don't know how this works) in the image directory

    Only tested with .png images but may work with others.

    :param image_directory:
    :type image_directory: pathlib.Path
    :param frames_per_second:
    :type frames_per_second: float
    :param kwargs: image_type='png' or other
    :return: nothing
    """
    assert isinstance(image_directory, pathlib.Path), "input must be a pathlib object"
    image_type = kwargs.get('type', 'png')

    timestampStr = datetime.now().strftime("%y%m%d_%H%M%S")
    gif_dir = image_directory.joinpath(timestampStr + "_GIF.gif")

    print('Started making GIF')
    print('Please wait... ')

    images = []
    for file_name in image_directory.glob('*.' + image_type):
        images.append(imageio.imread(image_directory.joinpath(file_name)))
    imageio.mimsave(gif_dir.as_posix(), images, fps=frames_per_second)

    print('Finished making GIF!')
    print('GIF can be found at: ' + gif_dir.as_posix())


def main():
    fps = 2
    png_dir = pathlib.Path('C:/temp/my_images')
    make_gif(png_dir, fps)

if __name__ == "__main__":
    main()