如何在python中将字节从字符串转换为图像？

Question

I have this byte object in string format inside a .txt file and I'm lost on how to convert it back into byte object, like img=b'\\x00\\x00\\x00' so that I can write it back into an image.

The image is supposed to be a black square when back to image format.

b'\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x00\xdd\x00\x00\x00\xdd\x08\x06\x00\x00\x00?\xc4w\x1a\x00\x00\x00\x01sRGB\x00\xae\xce\x1c\xe9\x00\x00\x00\x04gAMA\x00\x00\xb1\x8f\x0b\xfca\x05\x00\x00\x00\tpHYs\x00\x00\x0e\xc3\x00\x00\x0e\xc3\x01\xc7o\xa8d\x00\x00\x00!tEXtCreation Time\x002019:07:22 19:10:08\xa0\x9d\xf4\xb4\x00\x00\x02\x80IDATx^\xed\xd3\xb1\r\xc00\x00\xc30\xa7\xff\xff\xdcf\xe8\r\x9aH\xc0\xf0\x05:\xdb\xde; \xf2\xfc\x0fDD\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x10\x13\x1d\xc4D\x071\xd1ALt\x90\xda>\xddB\x02\xb9L3W\xe8\x00\x00\x00\x00IEND\xaeB`\x82'

Opening the file .txt file with the byte object

file=open('filename.txt','r').read()

I tried this, but the file is in a string format

with open('new_pic.png','wb')as img:
    img.write(file)

Answer 1

You should be reading the file as binary ( "rb" ).

file = open('filename.txt', 'rb').read()
print(type(file))  # <class 'bytes'>
print(file)        # b'\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x01\x06\x0

with open("image.png", "wb") as img:
    img.write(file)

Now, I don't know why you have image bytes stored in a text file, but a better implementation would be to use image-related modules like Pillow to read-write image files:

from PIL import Image

file = Image.open("input.png")
file.save("output.png")