ASCII.py

#For Python3 on Windows
from __future__ import division
from PIL import Image, ImageStat
import sys
import os
import re

#Dimension Enum
class dim:
    x = 0
    y = 1

#Get FileName function
def listFiles (ls):
    imageList = []
    for i in range (0, len (ls) ):
        if ( re.search ("\.(jpe?g|gif|png|bmp|tiff)$", ls[i]) ):
            print ( str(len(imageList)) + ". " + ls[i])
            imageList.append (ls[i])
    if ( len(imageList) == 0):
        _ = input("Error: No image files found")
        exit()
    if ( len(imageList) == 1):
        return imageList[0]
    while (True):
        index = getInteger("Enter selection number: ")
        if (index < len(imageList) and index >= 0):
            return imageList[ index ]
        print ("Error: input must be between %s and %s\n" % (0, len(imageList)-1) )

#Get integer from user input
def getInteger(query):
    while (True):
        try:
            return int( input(query) )
        except:
            print ("Error: input must be an integer\n")

#Rounding function
def round (number):
    diff = number - int(number)
    if (diff < .5):
        return int(number)
    else:
        return int(number) +1

#Prompt User / Set variables
print ("Image files in current directory:")
imageName = listFiles ( os.listdir() )
name = re.match( "(.+)\.", imageName )
fileName = "Renders\\" + name.group(1) + ".txt"
width = getInteger("Width of output file: ")
hdr = input ("Apply HDR? (y/n): ")
invert = input ("Invert image? (y/n): ")

#Initialization
defaultLetterset = "@%#x+=:- "
if not ( os.path.isdir("Renders") ):
    os.mkdir("Renders")
output = open(fileName, 'w')
if ( os.path.isfile("letterset.ini")):
    lettersetFile = open("letterset.ini", 'r+')
    letterset = lettersetFile.read()
    if ( len(letterset) < 2):
        letterset = defaultLetterset
        lettersetFile.write(defaultLetterset)
        print ("Error: letterset too short. Reverting to default")
else:
    lettersetFile = open("letterset.ini", 'w')
    lettersetFile.write(defaultLetterset)
    letterset = defaultLetterset
    print ("Error: letterset.ini not found: creating new file")
lettersetFile.close()
text = ""

#Load image and convert to greyscale
image = Image.open (imageName)
image = image.convert ('L')

#Resize image
ratio = width / image.size[dim.x]
height = round( ratio * image.size[dim.y] / 2) *2
image = image.resize((width,height))


#Apply Effects
data = []
stats = ImageStat.Stat(image)
[(min, max)] = stats.extrema
for y in range (0, image.size[dim.y]):
    for x in range (0, image.size[dim.x]):
        pixel = image.getpixel ((x,y))
        if (hdr != 'n'):
            offset = min - 0
            stretch = 255 / max
            pixel = (pixel - offset) * stretch
        if (invert == 'y'):
            pixel = 255 - pixel
        data.append (pixel)
image = Image.new ('L', image.size)
image.putdata (data)

#Generate ASCII
for y in range ( 0, image.size[dim.y], 2 ):
    for x in range ( 0, image.size[dim.x] ):
        brightness = ( image.getpixel(( x, y)) + image.getpixel((x,y+1)) ) / 2
        index = round( (brightness / 255) * len(letterset) ) -1
        text += letterset[ index ]
    text += "\n"

#Write to File
output.write( text )
output.close()
print ("Done")
os.startfile(fileName)