python小项目--图片转化为字符画

本文转自至：
https://www.shiyanlou.com/courses/370/labs/1191/document
获取图片命令：wget http://labfile.oss.aliyuncs.com/courses/370/ascii_dora.png
先要安装一个pillow库：

$ sudo apt-get update

$ sudo apt-get install python-dev

$ sudo apt-get install libtiff5-dev libjpeg8-dev zlib1g-dev \libfreetype6-dev liblcms2-dev libwebp-dev tcl8.6-dev tk8.6-dev python-tk

$ sudo pip install pillow

代码：

from PIL import Image

import argparse

#命令行输入参数处理

parser = argparse.ArgumentParser()

parser.add_argument('file')     #输入文件

parser.add_argument('-o', '--output')   #输出文件

parser.add_argument('--width', type = int, default = 80) #输出字符画宽

parser.add_argument('--height', type = int, default = 80) #输出字符画高

#获取参数

args = parser.parse_args()

IMG = args.file

WIDTH = args.width

HEIGHT = args.height

OUTPUT = args.output

ascii_char = list("$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,\"^`'. ")

# 将256灰度映射到70个字符上

def get_char(r,g,b,alpha = 256):

    if alpha == 0:

        return ' '

    length = len(ascii_char)

    gray = int(0.2126 * r + 0.7152 * g + 0.0722 * b)

    unit = (256.0 + 1)/length

    return ascii_char[int(gray/unit)]

if __name__ == '__main__':

    im = Image.open(IMG)

    im = im.resize((WIDTH,HEIGHT), Image.NEAREST)

    txt = ""

    for i in range(HEIGHT):

        for j in range(WIDTH):

            txt += get_char(*im.getpixel((j,i)))

        txt += '\n'

    print txt

    #字符画输出到文件

    if OUTPUT:

        with open(OUTPUT,'w') as f:

            f.write(txt)

    else:

        with open("output.txt",'w') as f:

            f.write(txt)