python动图处理图像

本篇文章给大家带来的内容是关于Python处理gif动态图的解析与合成操作的介绍，有一定的参考价值，有需要的朋友可以参考一下，希望对你有所帮助。

本文实例讲述了Python图像处理之gif动态图的解析与合成操作。分享给大家供大家参考，具体如下：

gif动态图是在现在已经司空见惯，朋友圈里也经常是一言不合就斗图。这里，就介绍下如何使用python来解析和生成gif图像。

一、gif动态图的合成

如下图，是一个gif动态图。

gif动态图的解析可以使用PIL图像模块即可，具体代码如下：#-*- coding: UTF-8 -*-

import os

from PIL import Image

def analyseImage(path):

'''

Pre-process pass over the image to determine the mode (full or additive).

Necessary as assessing single frames isn't reliable. Need to know the mode

before processing all frames.

'''

im = Image.open(path)

results = {

'size': im.size,

'mode': 'full',

}

try:

while True:

if im.tile:

tile = im.tile[0]

update_region = tile[1]

update_region_dimensions = update_region[2:]

if update_region_dimensions != im.size:

results['mode'] = 'partial'

break

im.seek(im.tell() + 1)

except EOFError:

pass

return results

def processImage(path):

'''

Iterate the GIF, extracting each frame.

'''

mode = analyseImage(path)['mode']

im = Image.open(path)

i = 0

p = im.getpalette()

last_frame = im.convert('RGBA')

try:

while True:

print "saving %s (%s) frame %d, %s %s" % (path, mode, i, im.size, im.tile)

'''

If the GIF uses local colour tables, each frame will have its own palette.

If not, we need to apply the global palette to the new frame.

'''

if not im.getpalette():

im.putpalette(p)

new_frame = Image.new('RGBA', im.size)

'''

Is this file a "partial"-mode GIF where frames update a region of a different size to the entire image?

If so, we need to construct the new frame by pasting it on top of the preceding frames.

'''

if mode == 'partial':

new_frame.paste(last_frame)

new_frame.paste(im, (0,0), im.convert('RGBA'))

new_frame.save('%s-%d.png' % (''.join(os.path.basename(path).split('.')[:-1]), i), 'PNG')

i += 1

last_frame = new_frame

im.seek(im.tell() + 1)

except EOFError:

pass

def main():

processImage('test_gif.gif')

if __name__ == "__main__":

main()

解析结果如下，由此可见改动态图实际上是由14张相同分辨率的静态图组合而成

二、gif动态图的合成

gif图像的合成，使用imageio库(https://pypi.python.org/pypi/imageio)

代码如下：#-*- coding: UTF-8 -*-

import imageio

def create_gif(image_list, gif_name):

frames = []

for image_name in image_list:

frames.append(imageio.imread(image_name))

# Save them as frames into a gif

imageio.mimsave(gif_name, frames, 'GIF', duration = 0.1)

return

def main():

image_list = ['test_gif-0.png', 'test_gif-2.png', 'test_gif-4.png',

'test_gif-6.png', 'test_gif-8.png', 'test_gif-10.png']

gif_name = 'created_gif.gif'

create_gif(image_list, gif_name)

if __name__ == "__main__":

main()

这里，使用第一步解析出来的图像中的8幅图，间副的间隔时间为0.1s，合成新的gif动态图如下：