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

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()

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])

使用windows7, python2.7, opencv 3.0,以下工作为我:

import cv2
import os

vvw           =   cv2.VideoWriter('mymovie.avi',cv2.VideoWriter_fourcc('X','V','I','D'),24,(640,480))
frameslist    =   os.listdir('.\\frames')
howmanyframes =   len(frameslist)
print('Frames count: '+str(howmanyframes)) #just for debugging

for i in range(0,howmanyframes):
    print(i)
    theframe = cv2.imread('.\\frames\\'+frameslist[i])
    vvw.write(theframe)

它不是一个python库,但mencoder可以做到这一点:从多个输入图像文件编码。你可以像这样从python中执行mencoder:

import os

os.system("mencoder ...")

我使用images2gif.py,这很容易使用。它似乎是文件大小的两倍。

26个110kb的PNG文件,我期望26*110kb = 2860kb,但my_gif.GIF是5.7mb

另外,因为GIF是8位的,好看的png在GIF中变得有点模糊

下面是我使用的代码:

__author__ = 'Robert'
from images2gif import writeGif
from PIL import Image
import os

file_names = sorted((fn for fn in os.listdir('.') if fn.endswith('.png')))
#['animationframa.png', 'animationframb.png', 'animationframc.png', ...] "

images = [Image.open(fn) for fn in file_names]

print writeGif.__doc__
# writeGif(filename, images, duration=0.1, loops=0, dither=1)
#    Write an animated gif from the specified images.
#    images should be a list of numpy arrays of PIL images.
#    Numpy images of type float should have pixels between 0 and 1.
#    Numpy images of other types are expected to have values between 0 and 255.


#images.extend(reversed(images)) #infinit loop will go backwards and forwards.

filename = "my_gif.GIF"
writeGif(filename, images, duration=0.2)
#54 frames written
#
#Process finished with exit code 0

以下是26帧中的3帧:

缩小图像会减小尺寸:

size = (150,150)
for im in images:
    im.thumbnail(size, Image.ANTIALIAS)

对我来说,使它工作的最简单的事情是在Python中调用shell命令。

如果您的图像存储为dummy_image_1.png, dummy_image_2.png…dummy_image_N.png,然后你可以使用函数:

import subprocess
def grid2gif(image_str, output_gif):
    str1 = 'convert -delay 100 -loop 1 ' + image_str  + ' ' + output_gif
    subprocess.call(str1, shell=True)

执行:

grid2gif("dummy_image*.png", "my_output.gif")

这将构造你的gif文件my_output.gif。