#!/usr/bin/env python3

gpib_address = "GPIB0::7::INSTR"

import pyvisa
import sys
from PIL import Image
rm = pyvisa.ResourceManager()
instr = rm.open_resource(gpib_address)
instr.write(':PRINT?')
answer = instr.read_raw(30742)
img = Image.frombytes("1", (640, 384), answer[23:])
img = img.crop((0, 0, 595, 384))
sys.stdout.buffer.write(b"Content-type: image/png\n\n")
img.save(sys.stdout.buffer, 'png')