#!/usr/bin/python

# usage: image_to_dcf.py myimage.png
# minimal program to write any image in a form that is suitable for
# viewing on a cybershot -- proof of concept only, no warranty ...
# ewan_at_mathcode_dot_net

# Chieh Cheng
# Version 1
# This python program is based originally the comments above.
# I have made the following changes:
# 1. Changed /usr/local/bin to /usr/bin
# 2. Changed image_to_dcf.py to DCF.py
# 3. Output file name as "DCF_xxxx.JPG", where xxxx is a unique number

import Image
import os
import sys

filename = sys.argv[1]
# input isn't checked,
# it is user's responsibility to make sure
# that input filename has 3-letter extension eg .jpg or .png

im = Image.open(filename)

def padZeros (num):
  result = ""
  if num < 1000:
    result = result + "0"
  if num < 100:
    result = result + "0"
  if num < 10:
    result = result + "0"
  result = result + str (num)
  return result

def getUniqueName ():
  count = 1
  name = 'DCF_' + padZeros (count) + '.JPG'
  while os.path.isfile (name):
    count = count + 1;
    name = 'DCF_' + padZeros (count) + '.JPG'
  return name

outfile = getUniqueName ()
# after conversion, you'll want to rename the output file
# to the format AAAANNNN.JPG, where 'AAAANNNN' has 8 characters,
# A representing an uppercase letter, N a number form 0001 to 9999

oim = im.copy()
oim = im.convert('YCbCr')
oim.mode = 'YCbCr'

oim.save(outfile, 'JPEG', quality=100)