import numpy as np
import cv2

cap = cv2.VideoCapture(0)

def nothing(x):
    pass


cv2.namedWindow("Trackbars")
cv2.createTrackbar("L - H", "Trackbars", 0, 255, nothing)
cv2.createTrackbar("L - S", "Trackbars", 0, 255, nothing)
cv2.createTrackbar("L - V", "Trackbars", 0, 255, nothing)
cv2.createTrackbar("U - H", "Trackbars", 255, 255, nothing)
cv2.createTrackbar("U - S", "Trackbars", 255, 255, nothing)
cv2.createTrackbar("U - V", "Trackbars", 255, 255, nothing)

while True:
    ret, frame = cap.read()
    frame = cv2.resize(frame, (640, 480))
    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    l_h = cv2.getTrackbarPos("L - H", "Trackbars")
    l_s = cv2.getTrackbarPos("L - S", "Trackbars")
    l_v = cv2.getTrackbarPos("L - V", "Trackbars")
    u_h = cv2.getTrackbarPos("U - H", "Trackbars")
    u_s = cv2.getTrackbarPos("U - S", "Trackbars")
    u_v = cv2.getTrackbarPos("U - V", "Trackbars")
    lower_range = np.array([l_h, l_s, l_v])
    upper_range = np.array([u_h, u_s, u_v])
    mask = cv2.inRange(hsv, lower_range, upper_range)
    result = cv2.bitwise_and(frame, frame, mask=mask)

    # show thresholded image
    cv2.imshow("mask", mask)
    cv2.imshow("result", result)

    key = cv2.waitKey(1) & 0xFF
    if key == ord("q"):
        break
cap.release()
cv2.destroyAllWindows()