ImageDecoder.py | Decode Text from Images

#! /usr/bin/env python
# ImageDecoder.py
# Author: Abdul Fatir
# E-Mail: [email protected]

from PIL import Image
import optparse

morse_dict={
    'A':'.-','B':'-...','C':'-.-.','D':'-..','E':'.','F':'..-.',
    'G':'--.','H':'....','I':'..','J':'.---','K':'-.-','L':'.-..',
    'M':'--','N':'-.','O':'---','P':'.--.','Q':'--.-','R':'.-.',
    'S':'...','T':'-','U':'..-','V':'...-','W':'.--','X':'-..-',
    'Y':'-.--','Z':'--..','0':'-----','1':'.----','2':'..---','3':'...--',
    '4':'....-','5':'.....','6':'-....','7':'--...','8':'---..','9':'----.',
    '.':'.-.-.-',',':'--..--','?':'..--..',"'":'.----.','/':'-..-.','(':'-.--.-',
    ')':'-.--.-',':':'---...',';':'-.-.-.','=':'-...-','+':'.-.-.','-':'-....-',
    '_':'..--.-','"':'.-..-.','$':'...-..-','':''
    }
def getLetterForMorse(l):

    for key, value in morse_dict.iteritems():
        if(value == l):
            return str(key)
def Main():
    parser = optparse.OptionParser('usage: python ImageDecoder.py -i <input PNG image name>')
    parser.add_option('-i',dest='inPNG',type='string',help='Please specify the input image file')
    (options,arg) = parser.parse_args()
    if (options.inPNG == None):
        print parser.usage
        exit(0)
    else:
        inPNG = options.inPNG
    _img = Image.open(inPNG)
    W = _img.size[0]
    H = _img.size[1]
    _pixs = _img.load()
    lastOff = 0
    _letter = ""
    answer = ""

    for y in range(H):
        for x in range(W):
            if(_pixs[x,y] == (255,255,255)):
                offset = y*100 + x - lastOff
                lastOff = y*100 + x
                _char = chr(offset)
                if(_char != ' '):
                    _letter += _char
                else:
                    answer += getLetterForMorse(_letter)
                    _letter = ""

    print answer

if __name__ == '__main__':
    Main()