You can save a picture in byte format inside a variable in your program. You can then convert the bytes back into a file-like object using the BytesIO function of the io module and plot that object using the Image module from the Pillow library.

import io
import PIL.Image

with open("filename.png", "rb") as file:
    img_binary = file.read()

img = PIL.Image.open(io.BytesIO(img_binary))
img.show()

To save the binary data inside your program without having to read from the source file you need to encode it with something like base64, use print() and then simply copy the output into a new variable and remove the file reading operation from your code.

That would look like this:

img_encoded = base64.encodebytes(img_binary)
print(img_binary)

img_encoded = " " # paste the output from the console into the variable

the output will be very long, especially if you are using a big image. I only used a very small png for testing.

This is how the program should look like at the end:

import io
import base64
import PIL.Image

# with open("filename.png", "rb") as file:
#    img_binary = file.read()
# img_encoded = base64.encodebytes(img_binary)

img_encoded = b'iVBORw0KGgoAAAANSUhEUgAAADAAAAAwCAYAAABX[...]'
img = PIL.Image.open(io.BytesIO(base64.decodebytes(img_encoded)))
img.show()

You can use the base64 module to embed data into your programs. From the base64 documentation:

Copy>>> import base64
>>> encoded = base64.b64encode('data to be encoded')
>>> encoded
'ZGF0YSB0byBiZSBlbmNvZGVk' 
>>> data = base64.b64decode(encoded)
>>> data
'data to be encoded'

Using this ability you can base64 encode an image and embed the resulting string in your program. To get the original image data you would pass that string to base64.b64decode.