highlightRink.py

    # shift the image x = -100, y = -100 since the pic generated has 100, 100 offset.
    rows, cols, d3 = rink.shape
    M = np.float32([[1, 0, -offset], [0, 1, -offset]])
    transformedImage = cv2.warpAffine(image, M, (cols, rows))

    # resize the rink image to match with play image.
    transformedRink = cv2.resize(rink, None, fx=300.0 * 2 / rows, fy=610.0 * 2 / cols, interpolation=cv2.INTER_CUBIC)
    # covert the transformRink to black/white mask
    rinkMask = cv2.cvtColor(transformedRink, cv2.COLOR_BGR2GRAY)
    h, rinkMask = cv2.threshold(rinkMask, 10, 255, cv2.THRESH_BINARY)
    cv2.imshow("rinkMask", rinkMask)

    # use this mask to truncate the play rink image
    rows, cols = rinkMask.shape
    imageMask = cv2.bitwise_and(cv2.cvtColor(rinkMask, cv2.COLOR_GRAY2BGR), transformedImage[0:rows, 0:cols])

    # convert the truncated play image (only have the rink part) to black/white mask
    imageMask = cv2.cvtColor(imageMask, cv2.COLOR_BGR2GRAY)
    h, imageMask = cv2.threshold(imageMask, 10, 255, cv2.THRESH_BINARY)
    cv2.imshow("imageMask", imageMask)

    # create the red mask to merge with the normalized rink image.
    cropImage = transformedImage[0:rows, 0:cols]
    cropImage[imageMask != 0] = [0, 0, 255]
    cropImage[imageMask == 0] = [0, 0, 0]
    cv2.imshow("cropImage", cropImage)

    highlightRink = cv2.addWeighted(cropImage, 0.1, transformedRink, 0.9, 0)

    cv2.imshow("highlightRink", highlightRink)