img2rawdump.py

img2rawdump.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

# img2rawdump.py - dump raw date from input image
#
# Copyright (C) 2011 Homin Lee <ff4500@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

import Image

def toYCbCr422(pixels):
    r1, g1, b1, a1 = pixels[0]
    r2, g2, b2, a2 = pixels[1]

    y1 = int(0.299 * r1 + 0.587 * g1 + 0.114 * b1)
    cb1 = 0.564 * (b1 - y1)
    cr1 = 0.713 * (r1 - y1)

    y2 = int(0.299 * r2 + 0.587 * g2 + 0.114 * b2)
    cb2 = 0.564 * (b2 - y2)
    cr2 = 0.713 * (r2 - y2)

    cb = int((cb1 + cb2) / 2)
    cr = int((cr1 + cr2) / 2)

    return map(lambda x:x&0xff, (y1, cb, cr, y2, cb, cr))

def toRGB565(pixels):
    r, g, b, a = pixels[0]

    b1 = ((r >> 3) << 3) + ((g >> 2) >> 3)
    b2 = ((g >> 2) << 5) + (b >> 3)

    return map(lambda x:x&0xff, (b2, b1)) # should swap the edian

convertDict = {
    'YCbCr422': (2, toYCbCr422),
    'RGB565': (1, toRGB565),
}

if __name__ == '__main__':
    from optparse import OptionParser
    optPsr = OptionParser("usage: %prog [-f FMT] input_imgs")
    optPsr.add_option('-f', '--fmt', type='string',
                    help="format: 'YCbCr422 or RGB565")
    (opts, args) = optPsr.parse_args()

    cStep, cFunc = convertDict[opts.fmt]
    for imgPath in args:
        img = Image.open(imgPath)
        dumpPath = imgPath + '_%dx%d.'%img.size + opts.fmt
        wp = open(dumpPath, 'wb')
        imgData = map(ord, list(img.tostring()))
        while(imgData):
            pixels = []
            for i in range(cStep):
                r = imgData.pop(0)
                g = imgData.pop(0)
                b = imgData.pop(0)
                if img.mode == 'RGBA':
                    a = imgData.pop(0)
                else:
                    a = 0xff
                pixels.append((r,g,b,a))

            retDump = cFunc(pixels)
            wp.write(''.join(map(chr, retDump)))

        wp.close()

# vim: et sw=4 fenc=utf-8: