#!python

from mt import np, cv

# termination criteria
criteria = (cv.TERM_CRITERIA_EPS + cv.TERM_CRITERIA_MAX_ITER, 30, 0.001)

# prepare object points, like (0,0,0), (1,0,0), (2,0,0) ....,(6,5,0)
objp = np.zeros((6 * 9, 3), np.float32)
objp[:, :2] = np.mgrid[0:9, 0:6].T.reshape(-1, 2)
# Arrays to store object points and image points from all the images.
objpoints = []  # 3d point in real world space
imgpoints = []  # 2d points in image plane.
vid = cv.VideoCapture(2)
print("Press ESC to quit.")
while True:
    vid.grab()
    ret, img = vid.retrieve()
    if not ret:
        break
    gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
    # Find the chess board corners
    ret, corners = cv.findChessboardCorners(gray, (9, 6), None)
    # If found, add object points, image points (after refining them)
    if ret == True:
        objpoints.append(objp)
        corners2 = cv.cornerSubPix(gray, corners, (11, 11), (-1, -1), criteria)
        imgpoints.append(corners2)
        # Draw and display the corners
        cv.drawChessboardCorners(img, (9, 6), corners2, ret)
    cv.imshow("img", img)
    c = cv.waitKey(1)
    if c == 27:
        break

cv.destroyAllWindows()
