使用PIL给图片加水印的工具类，pil工具类,#! /usr/bin/

使用PIL给图片加水印的工具类，pil工具类,#! /usr/bin/

#! /usr/bin/env python2.7# -*- coding: utf-8 -*-import Imageimport osclass WaterMark(object):    '''    水印工具类，提供基本的给图片打水印的功能    使用：        marker = WaterMark(path) # path为水印图片的路径        marker.mark(pic) # pic为待打水印的图片        marker.mark_dir(pic_dir) # pic_dir为待打水印的目录    '''    POSITION_TOP_LEFT = 0    POSITION_TOP_RIGHT = 1    POSITION_BOTTOM_LEFT = 2    POSITION_BOTTOM_RIGHT = 3    # 在原图片中打水印的区域    box = (0, 0, 0, 0)    backup_suffix = '.bak'    def _gen_mosaic(self, arg):        '''打开水印图片'''        try:            mosaic = Image.open(arg).convert('RGBA')        except IOError:            print 'cannot convert file.'        return mosaic    def __init__(self, *args, **kwargs):        if args:            arg = args[0]            self._mosaic = self._gen_mosaic(arg)    def _locate(self, image,  position=POSITION_BOTTOM_RIGHT):        '''定位原图片打水印的位置'''        w, h = self._mosaic.size        i_w, i_h = image.size        if position == self.POSITION_TOP_LEFT:            self.box = (0, 0, w, h)        elif position == self.POSITION_TOP_RIGHT:            self.box = (i_w - w, 0, i_w, h)        elif position == self.POSITION_BOTTOM_LEFT:            self.box = (0, i_h - h, w, i_h)        elif position == self.POSITION_BOTTOM_RIGHT:            self.box = (i_w - w, i_h - h, i_w, i_h)        else:            self.box = (0, 0, 0, 0)    def mark(self, path, position=POSITION_BOTTOM_RIGHT):        '''给单个图片打水印'''        try:            img = Image.open(path)        except IOError:            return None        if img.size[0] < self._mosaic.size[0]:            print 'width', img.size[0], self._mosaic.size[0]            return None        if img.size[1] < self._mosaic.size[1]:            print 'height', img.size[1], self._mosaic.size[1]            return None        img_area = img.size[0] * img.size[1]        mosaic_area = self._mosaic.size[0] * self._mosaic.size[1]        ratio = 4        if img_area < mosaic_area * ratio:            return None        self._locate(img, position)        layer = Image.new('RGBA', img.size, (0, 0, 0, 0))        layer.paste(self._mosaic, self.box)        return Image.composite(layer, img, layer)    def mark_dir(self, path, backup=False, position=POSITION_BOTTOM_RIGHT):        '''批量打水印'''        for root, dirs, files in os.walk(path):            for f in files:                path = os.path.join(root, f)                if path.endswith(self.backup_suffix):                    continue                print path                f_marked = self.mark(path)                if not f_marked:                    continue                if backup:                    os.rename(path, path + self.backup_suffix)                f_marked.save(path, f_marked.format)def test():    '''    用来测试打水印功能    命令行使用：        python watermark.py 水印图片路径 待打水印图片的目录    '''    import sys    if len(sys.argv) < 3:        return False    mosaic_path = sys.argv[1]    directory = sys.argv[2]    marker = WaterMark(mosaic_path)    marker.mark_dir(directory, backup=True)if __name__ == '__main__':    test()#该片段来自于http://byrx.net