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

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)

其他回答

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 ...")

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

我尝试了以下方法,非常有用:

首先下载Figtodat和images2gif库到本地目录。

其次,收集数组中的图形并将其转换为动画gif:

import sys
sys.path.insert(0,"/path/to/your/local/directory")
import Figtodat
from images2gif import writeGif
import matplotlib.pyplot as plt
import numpy

figure = plt.figure()
plot   = figure.add_subplot (111)

plot.hold(False)
    # draw a cardinal sine plot
images=[]
y = numpy.random.randn(100,5)
for i in range(y.shape[1]):
    plot.plot (numpy.sin(y[:,i]))  
    plot.set_ylim(-3.0,3)
    plot.text(90,-2.5,str(i))
    im = Figtodat.fig2img(figure)
    images.append(im)

writeGif("images.gif",images,duration=0.3,dither=0)

我看到这篇文章,没有一个解决方案是有效的,所以这里是我的解决方案是有效的

到目前为止,其他解决方案存在的问题: 1)对于如何修改持续时间没有明确的解决方案 2)对于乱序目录迭代没有解决方案,而乱序目录迭代对于动图是必不可少的 3)没有说明如何为python3安装imageio

像这样安装imageio: python3 -m PIP Install imageio

注意:你要确保你的帧在文件名中有某种索引,这样它们就可以排序,否则你就无法知道GIF从哪里开始或结束

import imageio
import os

path = '/Users/myusername/Desktop/Pics/' # on Mac: right click on a folder, hold down option, and click "copy as pathname"

image_folder = os.fsencode(path)

filenames = []

for file in os.listdir(image_folder):
    filename = os.fsdecode(file)
    if filename.endswith( ('.jpeg', '.png', '.gif') ):
        filenames.append(filename)

filenames.sort() # this iteration technique has no built in order, so sort the frames

images = list(map(lambda filename: imageio.imread(filename), filenames))

imageio.mimsave(os.path.join('movie.gif'), images, duration = 0.04) # modify duration as needed

正如上面提到的一个成员,imageio是一种很好的方法。imageio还允许你设置帧速率,我实际上用Python写了一个函数,允许你设置最后一帧的暂停。我将此函数用于科学动画,其中循环是有用的,但立即重新启动不是。下面是链接和函数:

如何使用Python制作GIF

import matplotlib.pyplot as plt
import os
import imageio

def gif_maker(gif_name,png_dir,gif_indx,num_gifs,dpi=90):
    # make png path if it doesn't exist already
    if not os.path.exists(png_dir):
        os.makedirs(png_dir)

    # save each .png for GIF
    # lower dpi gives a smaller, grainier GIF; higher dpi gives larger, clearer GIF
    plt.savefig(png_dir+'frame_'+str(gif_indx)+'_.png',dpi=dpi)
    plt.close('all') # comment this out if you're just updating the x,y data

    if gif_indx==num_gifs-1:
        # sort the .png files based on index used above
        images,image_file_names = [],[]
        for file_name in os.listdir(png_dir):
            if file_name.endswith('.png'):
                image_file_names.append(file_name)       
        sorted_files = sorted(image_file_names, key=lambda y: int(y.split('_')[1]))

        # define some GIF parameters

        frame_length = 0.5 # seconds between frames
        end_pause = 4 # seconds to stay on last frame
        # loop through files, join them to image array, and write to GIF called 'wind_turbine_dist.gif'
        for ii in range(0,len(sorted_files)):       
            file_path = os.path.join(png_dir, sorted_files[ii])
            if ii==len(sorted_files)-1:
                for jj in range(0,int(end_pause/frame_length)):
                    images.append(imageio.imread(file_path))
            else:
                images.append(imageio.imread(file_path))
        # the duration is the time spent on each image (1/duration is frame rate)
        imageio.mimsave(gif_name, images,'GIF',duration=frame_length)