Digram based binary visualization

digram_visualization.py

#!/usr/bin/env python3

from collections import Counter
from PIL import Image
import math, os, sys

def create_image(filename):
	# build digram
	digram = Counter()
	with open(filename, 'rb') as f:
		y = ord(f.read(1))
		for x in f.read():
			digram.update([(x,y)])
			y = x

	# log normal data
	for key in digram:
		digram[key] = math.log(digram[key], 256)

	# make image
	img = Image.new('F', (256, 256), 0)
	for point in digram:
		color = digram[point] * 255
		img.putpixel(point, color)

	img.convert('RGB').save('%s.png' % os.path.basename(filename))

def main():
	try:
		filename = sys.argv[1]
	except Exception as e:
		print('Error: missing filename')
		return
	else:
		if os.path.isfile(filename):
			create_image(filename)

if __name__ == '__main__':
	main()