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 osfrom PIL import Imagedef 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 resultsdef 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: passdef 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 imageiodef 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) returndef 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：
希望本文所述对大家Python程序设计有所帮助。
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