python 使图片变灰

参考博客: https://www.cnblogs.com/zhangjiansheng/p/6925722.html

# coding=gbk
from PIL import Image


# 灰度策略
def strategy_avg(r, g, b):
    return int((r + g + b) / 3)


def strategy_seven(r, g, b):
    return int((r*38 + g*75 + b*15) >> 7)


# 灰度转换
def imageToGray(strategy):
    # 读取图片
    im = Image.open("test.jpg")

    width = im.size[0]
    height = im.size[1]
    im = im.convert('RGB')
    for x in range(width):
        for y in range(height):
            r, g, b = im.getpixel((x, y))
            # 灰度策略
            avg = strategy(r, g, b)
            im.putpixel((x, y), (avg, avg, avg))
    # 展示转换结果
    im.show()


imageToGray(strategy_seven)

原图：(来自网图)

灰度后：