python 添加图片水印

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python 真是越来越喜欢了，以前要一天的工作，现在用python 几个小时就能处理完，而且效果很理想～～ 因为网站经常有采集现象发生，所以想给所有图片增加水印，即使采走也帮我做宣传。

为了能使加的水印漂亮，水印文件想使用png格式，这样就能保证水印的平滑 漂亮，而且加上发光效果更帅～ 哈哈

python代码总是很短 ，经过几次调整，已经忘了最早的出处了 反正都是分享～～

# -*- coding: utf-8 -*-

import Image, ImageEnhance

POSITION = ('LEFTTOP','RIGHTTOP','CENTER','LEFTBOTTOM','RIGHTBOTTOM')

PADDING = 10

MARKIMAGE = 'water.png'

def reduce_opacity(im, opacity):

"""Returns an image with reduced opacity."""

assert opacity >= 0 and opacity <= 1

if im.mode != 'RGBA':

im = im.convert('RGBA')

else:

im = im.copy()

alpha = im.split()[3]

alpha = ImageEnhance.Brightness(alpha).enhance(opacity)

im.putalpha(alpha)

return im

def watermark(imagefile, markfile, position=POSITION[4], opacity=1):

"""Adds a watermark to an image."""

im = Image.open(imagefile)

mark = Image.open(markfile)

if opacity < 1:

mark = reduce_opacity(mark, opacity)

if im.mode != 'RGBA':

im = im.convert('RGBA')

# create a transparent layer the size of the image and draw the

# watermark in that layer.

layer = Image.new('RGBA', im.size, (0,0,0,0))

if position == 'title':

for y in range(0, im.size[1], mark.size[1]):

for x in range(0, im.size[0], mark.size[0]):

layer.paste(mark, (x, y))

elif position == 'scale':

# scale, but preserve the aspect ratio

ratio = min(

float(im.size[0]) / mark.size[0], float(im.size[1]) / mark.size[1])

w = int(mark.size[0] * ratio)

h = int(mark.size[1] * ratio)

mark = mark.resize((w, h))

layer.paste(mark, ((im.size[0] - w) / 2, (im.size[1] - h) / 2))

elif position == POSITION[0]:

#lefttop

position = (PADDING,PADDING)

layer.paste(mark, position)

elif position == POSITION[1]:

#righttop

position = (im.size[0] - mark.size[0]-PADDING, PADDING)

layer.paste(mark, position)

elif position == POSITION[2]:

#center

position = ((im.size[0] - mark.size[0])/2,(im.size[1] - mark.size[1])/2)

layer.paste(mark, position)

elif position == POSITION[3]:

#left bottom

position = (PADDING,im.size[1] - mark.size[1]-PADDING,)

layer.paste(mark, position)

else:

#right bottom (default)

position = (im.size[0] - mark.size[0]-PADDING, im.size[1] - mark.size[1]-PADDING,)

layer.paste(mark, position)

# composite the watermark with the layer

return Image.composite(layer, im, layer)

watermark(new_image_s_filename,MARKIMAGE,POSITION[4],opacity=1).save(new_image_s_filename,quality=90)