python生成缩略图

一、环境配置

确保系统安装了libjpeg libjpeg-dev libfreetype6 libfreetype6-dev zlib1g-dev

如果系统未安装，则会出现  JPEG support not available的异常。 安装libjpeg-dev需要注意对安装的库文件生成链接，即执行：

# ln -s /usr/lib/i386-linux-gnu/libjpeg.so /usr/lib

# ln -s /usr/lib/i386-linux-gnu/libfreetype.so /usr/lib

# ln -s /usr/lib/i386-linux-gnu/libz.so /usr/lib

然后删掉 PIL 的解压文件，重新解压一份再安装即可。

二、使用PIL生成缩略图

#-*-!/usr/bin/env python-*-#-*-coding=utf-8-*-from PIL import Imageimport osimport sysimport fnmatchimport loggingclass ThumbnailGenerator:    # --*-- exts 为规定的后缀名列表，空则获取所有类型文件 --*--    def __getFileList(self, path, exts=None, subdir=True):        if os.path.exists(path):            dirlist = []            for name in os.listdir(path):                fullname = os.path.join(path, name)                if os.path.isdir(fullname):                    dirlist += self.getFileList(fullname,exts)                else:                    if exts and len(exts) > 0:                        for ext in exts:                            if fnmatch.fnmatch(fullname, ext):                                dirlist.append(fullname)                                break                    elif exts == None or len(exts) == 0:                        dirlist.append(fullname)                                    return dirlist        else:            return []    # --*-- sizes 参数传递要生成的尺寸，可以生成多种尺寸，每个size是一个二值元组 --*--    def __make_thumb(self, source_file, dest_path, sizes):        basename = os.path.basename(source_file)        dest_path         try:            im = Image.open(source_file)        except IOError, e:            logging.error('Open %s error: ' + str(e), source_file)            return        mode = im.mode        if mode not in ('L', 'RGB'):            if mode == 'RGBA':                # 透明图片需要加白色底                alpha = im.split()[3]                bgmask = alpha.point(lambda x: 255-x)                im = im.convert('RGB')                # paste(color, box, mask)                im.paste((255,255,255), None, bgmask)            else:                im = im.convert('RGB')                        width, height = im.size        if width == height:            region = im        else:            if width > height:                delta = (width - height)/2                box = (delta, 0, delta+height, height)            else:                delta = (height - width)/2                box = (0, delta, width, delta+width)             region = im.crop(box)                        for size in sizes:            filename = os.path.join(dest_path,basename)            thumb = region.resize((size[0],size[1]), Image.ANTIALIAS)            thumb.save(filename, quality=100) # 默认 JPEG 保存质量是 75, 不太清楚。可选值(0~100)    def thumb_generate(self, source_path, dest_path, sizes, subdir=True):        exts = ['*.jpg','*.png','*.JPG','*.PNG']        file_list = self.__getFileList(source_path, exts, subdir)        for file in file_list:            try:                self.__make_thumb(file, dest_path, sizes)            except Exception, e:                logging.error('Thumb %s error: ' + str(e), file)if __name__ == '__main__':    logging.basicConfig(filename='thumb.log',filemode='w',format='[%(asctime)s]-%(levelname)s : %(message)s',level=logging.DEBUG)    sizes = [(128,96)]    source_path = '201206'    dest_path = 's'    generator = ThumbnailGenerator()    generator.thumb_generate(source_path,dest_path,sizes)