from struct import *

ch = ['.', ':', '!', '~', '+','=', '^', '*','$', '#']//可以在这里面由浅到深添加字符
ch.reverse()

def calc(R, G, B):#模式L
    return R * 299 // 1000 + G * 587 // 1000 + B * 144 / 1000


def character( val):
    num = val / 260 * len(ch)
    num = round(num)
    if num>=len(ch):
        num=len(ch)-1
    return ch[num]

class rmb:
    def __init__(self, path):
        file = open(path, 'rb')

        self.bfType = file.read(2)
        self.bfSize = file.read(4)
        self.bfReserved1 = file.read(2)
        self.bfReserved2 = file.read(2)
        self.bfOffBits = file.read(4)

        self.biSize = file.read(4)
        self.biWidth = file.read(4)
        self.biHeight = file.read(4)
        self.biPlanes = file.read(2)
        self.biBitCount = file.read(2)

        self.biCompression = file.read(4)
        self.biSizeImage = file.read(4)
        self.biXPelsPerMeter = file.read(4)
        self.biYPelsPerMeter = file.read(4)
        self.biClrUsed = file.read(4)
        self.biClrImportant = file.read(4)
        self.bmp_data = []

        self.h, = unpack("<i", self.biHeight)
        self.w, = unpack("<i", self.biWidth)
        print(self.h)
        print(self.w)

        for height in range(self.h):
            bmp_data_row = []
            count = 0
            for width in range(self.w):
                bmp_data_row.append(
                    [unpack("<B", file.read(1))[0], unpack("<B", file.read(1))[0], unpack("<B", file.read(1))[0]])
                count += 3

            while count % 4 != 0:
                file.read(1)
                count += 1
            self.bmp_data.append(bmp_data_row)
        self.bmp_data.reverse()
        file.close()

    def write_(self):
        res_file = open('res.txt', 'w')

        for height in range(self.h):
            bmp_data_row = self.bmp_data[height]
            for width in range(self.w):
                R = bmp_data_row[width][0]
                G = bmp_data_row[width][1]
                B = bmp_data_row[width][2]
                res_file.write(character(calc(R,G,B)))
            res_file.write('\n')


res = rmb('1.bmp')#图片路径bmp格式
res.write_()