invalidArea = 255 * np.logical_and(BW, np.logical_not(finalBW)).astype('uint8')
cv2.imshow('Original', orig)
cv2.imshow('Final', finalBW)
cv2.imshow('Invalid Area', invalidArea)
cv2.waitKey(0)
cv2.destroyAllWindows()
Check for areas that are too thin in an image