python 给图片添加数字水印示例

【实例截图】

【核心代码】

# -*- coding: utf-8 -*-
"""
Spyder Editor

This is a temporary script file.
"""

from PIL import Image
import numpy as np
count = 85
def addWaterMark(pic, mark):
    img = Image.open(pic).convert("RGB")
    width, height = img.size
    img = img.point(lambda i : (int(i >> 2))<< 2)
    img = list(img.getdata())
    mark = Image.open(mark).convert("RGB")
    mark = mark.resize((width, height))
    mark = mark.point(lambda i : round(i / count))
    mark = list(mark.getdata())
    output = [0 for i in range(len(img))]
    for i in range(len(img)):
        temp = []
        for j in  range(3):
            temp.append(img[i][j]   mark[i][j])
        output[i] = tuple(temp)
    im = Image.new("RGB", (width, height))
    im.putdata(data = output)
    im.save('output.png')
    return

def testwatermark(pic, mark):
    img = Image.open(pic).convert("RGB")
    width, height = img.size
    mark1 = Image.open(mark).convert("RGB")
    w, h = mark1.size
    mark1 = mark1.resize((width, height))
    mark1 = mark1.point(lambda i : round(i / count) * count)
    mark1 = mark1.resize((w, h))
    mark2 = img.point(lambda i : (int(i & 3) * count))
    mark2 = mark2.resize((w, h))
    mark2.save('watermark2.png')
    m1 = mark1.convert("L");
    m2 = mark2.convert("L")
    d1 = m1.getdata()
    d2 = m2.getdata()
    d1 = np.mat(d1) / 255.0
    d2 = np.mat(d2) / 255.0
    corr = np.corrcoef(d1, d2)
    corr = np.mean(corr.flatten())
    return corr
addWaterMark('carry.bmp', 'watermark1.png')
test = testwatermark('output.png', 'watermark1.png')
if test > 0.8:
    print('水印验证成功!')
else:
    print('水印验证失败!')