#!/usr/bin/python

import cv2.cv as cv

import sys

import urllib2

if __name__ == "__main__":

    cv.NamedWindow("win")

    if len(sys.argv) > 1:

        filename = sys.argv[1]

        im = cv.LoadImage(filename, cv.CV_LOAD_IMAGE_GRAYSCALE)

        im3 = cv.LoadImage(filename, cv.CV_LOAD_IMAGE_COLOR)

    else:

        try: # try opening local copy of image

            fileName = '../cpp/left01.jpg'

            im = cv.LoadImageM(fileName, False)

            im3 = cv.LoadImageM(fileName, True)

        except: # if local copy cannot be opened, try downloading it

            url = 'https://code.ros.org/svn/opencv/trunk/opencv/samples/cpp/left01.jpg'

            filedata = urllib2.urlopen(url).read()

            imagefiledata = cv.CreateMatHeader(1, len(filedata), cv.CV_8UC1)

            cv.SetData(imagefiledata, filedata, len(filedata))

            im = cv.DecodeImageM(imagefiledata, cv.CV_LOAD_IMAGE_GRAYSCALE)

            im3 = cv.DecodeImageM(imagefiledata, cv.CV_LOAD_IMAGE_COLOR)

    chessboard_dim = ( 9, 6 )

    found_all, corners = cv.FindChessboardCorners( im, chessboard_dim )

    print found_all, len(corners)

    cv.DrawChessboardCorners( im3, chessboard_dim, corners, found_all )

    cv.ShowImage("win", im3);

    cv.WaitKey()