img = cv2.imread('imgs/bulls.jpg')
hsv_img = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)

court_color = np.uint8([[[160,221,248]]])
hsv_court_color = cv2.cvtColor(court_color, cv2.COLOR_BGR2HSV)
hue = hsv_court_color[0][0][0]

# define range of blue color in HSV
lower_color = np.array([hue - 10,10,10])
upper_color = np.array([hue + 10,255,255])

# Threshold the HSV image to get only blue colors
mask = cv2.inRange(hsv_img, lower_color, upper_color)

# Bitwise-AND mask and original image
res = cv2.bitwise_and(img,img, mask= mask)

plt.imshow(cv2.cvtColor(img, cv2.COLOR_BGR2RGB)), plt.title('Original Image'), plt.show()
plt.imshow(mask, cmap='Greys'), plt.title('Mask'), plt.savefig('imgs/mask.jpg'), plt.show()

# Erosion
kernel = np.ones((2,2),np.uint8)
erosions2 = cv2.erode(mask,kernel,iterations = 5)

# Dilation
dilation = cv2.dilate(mask,kernel,iterations = 3)

# Opening
opening = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel)

# Closing
closing = cv2.morphologyEx(mask, cv2.MORPH_CLOSE, kernel)