text: #! /usr/bin/env python
  # -*- coding:utf-8 -*-
  
  import cv2
  import numpy as np
  import glob
  
  # Load previously saved data
  with np.load( 'B.npz' ) as X :
  	mtx, dist, _, _ = [ X[i] for i in ('mtx','dist','rvecs','tvecs') ]
  
  def draw(img, corners, imgpts):
  	corner = tuple(corners[0].ravel())
  	img = cv2.line(img, corner, tuple(imgpts[0].ravel()), (255,0,0), 5)
  	img = cv2.line(img, corner, tuple(imgpts[1].ravel()), (0,255,0), 5)
  	img = cv2.line(img, corner, tuple(imgpts[2].ravel()), (0,0,255), 5)
  	return img
  
  def draw2(img, corners, imgpts):
  	imgpts = np.int32(imgpts).reshape(-1,2)
  	# draw ground floor in green
  	img = cv2.drawContours(img, [imgpts[:4]],-1,(0,255,0),-3)
  	# draw pillars in blue color
  	for i,j in zip(range(4),range(4,8)):
  		img = cv2.line(img, tuple(imgpts[i]), tuple(imgpts[j]),(255),3)
  	# draw top layer in red color
  	img = cv2.drawContours(img, [imgpts[4:]],-1,(0,0,255),3)
  	return img
  
  criteria = (cv2.TERM_CRITERIA_EPS + cv2.TERM_CRITERIA_MAX_ITER, 30, 0.001)
  objp = np.zeros((7*7,3), np.float32)
  objp[:,:2] = np.mgrid[0:7,0:7].T.reshape(-1,2)
  axis = np.float32([[3,0,0], [0,3,0], [0,0,-3]]).reshape(-1,3)
  axis2 = np.float32([[0,0,0], [0,3,0], [3,3,0], [3,0,0],[0,0,-3],[0,3,-3],[3,3,-3],[3,0,-3] ])
  
  for fname in glob.glob('../CameraCalibration/camera*.png'):
  	img = cv2.imread(fname)
  	gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
  	ret, corners = cv2.findChessboardCorners(gray, (7,7),None)
  	if ret == True:
  		corners2 = cv2.cornerSubPix(gray,corners,(11,11),(-1,-1),criteria)
  		# Find the rotation and translation vectors.
  		_,rvecs, tvecs, inliers = cv2.solvePnPRansac(objp, corners2, mtx, dist)
  		# project 3D points to image plane
  #		imgpts, jac = cv2.projectPoints(axis, rvecs, tvecs, mtx, dist)
  #		img = draw(img,corners2,imgpts)
  		imgpts, jac = cv2.projectPoints(axis2, rvecs, tvecs, mtx, dist)
  		img = draw2(img,corners2,imgpts)
  		cv2.imshow('img',img)
  		k = cv2.waitKey(0) & 0xff
  		if k == 's':
  			cv2.imwrite(fname[:6]+'.png', img)
  	cv2.destroyAllWindows()
  