import cv2
import numpy as np
import glob
################################################################################

print 'criteria and object points set'

# termination criteria
criteria = (3L, 30, 0.001)

# prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(8,5,0)
objpoint = np.zeros((9 * 6, 3), np.float32)
objpoint[:,:2] = np.mgrid[0:9, 0:6].T.reshape(-1,2)

# arrays to store object points and image points from all the images

# 3d point in real world space
objpoints = []
# 2d points in image plane
imgpoints = []
################################################################################

print 'Load Images'

images = glob.glob('images/Phone Camera/*.bmp')

for frame in images:
    
    img = cv2.imread(frame)
    imgGray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

    # find chess board corners
    ret, corners = cv2.findChessboardCorners(imgGray, (9,6), None)
    
    # print ret to check if pattern size is set correctly 
    print ret
    
    # if found, add object points, image points (after refining them)
    if ret == True:
        
        # add object points
        objpoints.append(objpoint)
        cv2.cornerSubPix(imgGray, corners, (11,11), (-1,-1), criteria)        
        # add corners as image points
        imgpoints.append(corners)

        # draw corners
        cv2.drawChessboardCorners(img, (9,6), corners, ret)

        cv2.imshow('Image',img)
        cv2.waitKey(0)
        cv2.destroyAllWindows()

################################################################################

print 'camera matrix'

ret, camMat, distortCoffs, rotVects, transVects = cv2.calibrateCamera(objpoints, imgpoints, imgGray.shape[::-1],None,None)
################################################################################

print 're-projection error'

meanError = 0
for i in xrange(len(objpoints)):
    imgpoints2, _ = cv2.projectPoints(objpoints[i], rotVects[i], transVects[i], camMat, distortCoffs)
    error = cv2.norm(imgpoints[i], imgpoints2, cv2.NORM_L2) / len(imgpoints2)
    meanError += error

print "total error: ", meanError / len(objpoints)
################################################################################

def drawAxis(img, corners, imgpoints):
    
    corner = tuple(corners[0].ravel())
    cv2.line(img, corner, tuple(imgpoints[0].ravel()), (255,0,0), 5)
    cv2.line(img, corner, tuple(imgpoints[1].ravel()), (0,255,0), 5)
    cv2.line(img, corner, tuple(imgpoints[2].ravel()), (0,0,255), 5)
    
    return img
################################################################################

def drawCube(img, corners, imgpoints):
    
    imgpoints = np.int32(imgpoints).reshape(-1,2)

    # draw ground floor in green color
    cv2.drawContours(img, [imgpoints[:4]], -1, (0,255,0), -3)

    # draw pillars in blue color
    for i,j in zip(range(4), range(4,8)):
        cv2.line(img, tuple(imgpoints[i]), tuple(imgpoints[j]), (255,0,0), 3)

    # draw top layer in red color
    cv2.drawContours(img, [imgpoints[4:]], -1, (0,0,255), 3)

    return img
################################################################################

print 'pose calculation'    
            
axis = np.float32([[3,0,0], [0,3,0], [0,0,-3]]).reshape(-1,3)
axisCube = 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 frame in glob.glob('images/Phone Camera/*.bmp'):
    
    img = cv2.imread(frame)

    gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
    ret, corners = cv2.findChessboardCorners(gray, (9,6), None)

    if ret == True:

        # find the rotation and translation vectors.
        rotVects, transVects, inliers = cv2.solvePnPRansac(objpoint, corners, camMat, distortCoffs)

        # project 3D points to image plane
        '''
        imgpoints, jac = cv2.projectPoints(axis, rotVecs, transVecs, camMat, distortCoffs)
        img = drawAxis(img, corners, imgpoints)
        '''
        
        imgpoints, jac = cv2.projectPoints(axisCube, rotVects, transVects, camMat, distortCoffs)
        img = drawCube(img, corners, imgpoints)
                
        cv2.imshow('Image with Pose', img)
        
        cv2.waitKey(0)
        cv2.destroyAllWindows()