from PIL import Image
im_orig = Image.open('input-black.gif')
big = im_orig.resize((116, 56), Image.NEAREST)
big.save("input-NEAREST.tif")
image = Image.open('input-NEAREST.tif')
 

Traceback (most recent call last):
  File "reccap.py", line 4, in <module>
  File "PIL\Image.pyc", line 1423, in save
KeyError: '.tif'

Traceback (most recent call last):
  File "reccap.py", line 19, in <module>
  File "pytesser.pyc", line 31, in image_to_string
  File "pytesser.pyc", line 21, in call_tesseract
  File "subprocess.pyc", line 623, in __init__
  File "subprocess.pyc", line 833, in _execute_child
WindowsError: [Error 2] El sistema no puede encontrar el archivo especificado

image = Image.open('input-NEAREST.tif')

from pytesser import *
from PIL import TiffImagePlugin
from PIL import Image
import os
img = Image.open('captcha.png')
img = img.convert("RGBA")
pixdata = img.load()
# Por cada pixel que no sea negro lo convertimos en blanco
for y in xrange(img.size[1]):
    for x in xrange(img.size[0]):
        if pixdata[x, y] != (0, 0, 0, 255):
            pixdata[x, y] = (255, 255, 255, 255)
img.save("input-black.gif", "GIF")
# Hacer la imagen mas grander (requerido para OCR)
im_orig = Image.open('input-black.gif')
big = im_orig.resize((116, 56), Image.NEAREST)
ext = ".tif"
big.save("input-NEAREST" + ext)
image = Image.open('input-NEAREST.tif')
captcha = image_to_string(image).split()[0]
print captcha