没有库的python代码

Question

我想在python中创建一个bmp图像而不使用任何内置库，如下图像：

请告诉我该怎么做？

Answer 1

使用BMP file format，您只需创建自己的BMP文件：

import math
import struct

width = 200
height = 200
bits_per_pixel = 24

# bitmap file header
data = 'BM' # Windows 3.1x, 95, NT, ... etc.
data += struct.pack('i', 26 + bits_per_pixel / 8 * width * height) # The size of the BMP file in bytes = header + (color bytes * w * h)
data += struct.pack('h', 0) # Reserved
data += struct.pack('h', 0) # Reserved
data += struct.pack('i', 26) # The offset, i.e. starting address, of the byte where the bitmap image data (pixel array) can be found.
# bitmap header (BITMAPCOREHEADER)
data += struct.pack('i', 12) # The size of this header (12 bytes)
data += struct.pack('h', width) # width
data += struct.pack('h', height) # height
data += struct.pack('h', 1) # The number of color planes, must be 1
data += struct.pack('h', bits_per_pixel) # The number of bits per pixel, which is the color depth of the image. Typical values are 1, 4, 8, 16, 24 and 32.

def rgb_to_bmp_data(r, g, b):
    return chr(b) + chr(g) + chr(r)

row_bytes = width * (bits_per_pixel / 8)
row_padding = int(math.ceil(row_bytes / 4.0)) * 4 - row_bytes

for y in xrange(height - 1, -1, -1):
    for x in xrange(width):
        if (y / 25) % 2:
            if (x / 25) % 2:
                data += rgb_to_bmp_data(255, 255, 255)
            else:
                data += rgb_to_bmp_data(0, 0, 0)
        else:
            if (x / 25) % 2:
                data += rgb_to_bmp_data(0, 0, 0)
            else:
                data += rgb_to_bmp_data(255, 255, 255)
    # add padding
    data += '\x00' * row_padding

with open('out.bmp', 'wb') as f:
    f.write(data)

图像结果接近您的需要：