OpenCV Python Tutorial For Beginners - Object Detection and Object Tracking Using HSV Color Space

opencv_python_object_detection.py

import cv2
import numpy as np

def nothing(x):
    pass

cv2.namedWindow("Tracking")
cv2.createTrackbar("LH", "Tracking", 0, 255, nothing)
cv2.createTrackbar("LS", "Tracking", 0, 255, nothing)
cv2.createTrackbar("LV", "Tracking", 0, 255, nothing)
cv2.createTrackbar("UH", "Tracking", 255, 255, nothing)
cv2.createTrackbar("US", "Tracking", 255, 255, nothing)
cv2.createTrackbar("UV", "Tracking", 255, 255, nothing)

while True:
    frame = cv2.imread('smarties.png')

    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    l_h = cv2.getTrackbarPos("LH", "Tracking")
    l_s = cv2.getTrackbarPos("LS", "Tracking")
    l_v = cv2.getTrackbarPos("LV", "Tracking")

    u_h = cv2.getTrackbarPos("UH", "Tracking")
    u_s = cv2.getTrackbarPos("US", "Tracking")
    u_v = cv2.getTrackbarPos("UV", "Tracking")

    l_b = np.array([l_h, l_s, l_v])
    u_b = np.array([u_h, u_s, u_v])

    mask = cv2.inRange(hsv, l_b, u_b)

    res = cv2.bitwise_and(frame, frame, mask=mask)

    cv2.imshow("frame", frame)
    cv2.imshow("mask", mask)
    cv2.imshow("res", res)

    key = cv2.waitKey(1)
    if key == 27:
        break

cv2.destroyAllWindows()

opencv_python_object_detection_video.py

import cv2
import numpy as np

def nothing(x):
    pass

cap = cv2.VideoCapture(0);

cv2.namedWindow("Tracking")
cv2.createTrackbar("LH", "Tracking", 0, 255, nothing)
cv2.createTrackbar("LS", "Tracking", 0, 255, nothing)
cv2.createTrackbar("LV", "Tracking", 0, 255, nothing)
cv2.createTrackbar("UH", "Tracking", 255, 255, nothing)
cv2.createTrackbar("US", "Tracking", 255, 255, nothing)
cv2.createTrackbar("UV", "Tracking", 255, 255, nothing)

while True:
    #frame = cv2.imread('smarties.png')
    _, frame = cap.read()

    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)

    l_h = cv2.getTrackbarPos("LH", "Tracking")
    l_s = cv2.getTrackbarPos("LS", "Tracking")
    l_v = cv2.getTrackbarPos("LV", "Tracking")

    u_h = cv2.getTrackbarPos("UH", "Tracking")
    u_s = cv2.getTrackbarPos("US", "Tracking")
    u_v = cv2.getTrackbarPos("UV", "Tracking")

    l_b = np.array([l_h, l_s, l_v])
    u_b = np.array([u_h, u_s, u_v])

    mask = cv2.inRange(hsv, l_b, u_b)

    res = cv2.bitwise_and(frame, frame, mask=mask)

    cv2.imshow("frame", frame)
    cv2.imshow("mask", mask)
    cv2.imshow("res", res)

    key = cv2.waitKey(1)
    if key == 27:
        break

cap.release()
cv2.destroyAllWindows()

@pknowledge i did copy and paste of your code but its not working just like mine is not working
Here is my code:
`import cv2 as cv
import numpy as np

def nothing(x):
pass

cv.namedWindow('Tracking')
cv.createTrackbar('Lower_Hue', 'Tracking', 0, 255, nothing)
cv.createTrackbar('Lower_Saturation', 'Tracking', 0, 255, nothing)
cv.createTrackbar('Lower_Value', 'Tracking', 0, 255, nothing)
cv.createTrackbar('Upper_Hue', 'Tracking', 255, 255, nothing)
cv.createTrackbar('Upper_Saturation', 'Tracking', 255, 255, nothing)
cv.createTrackbar('Upper_Value', 'Tracking', 255, 255, nothing)

while True:
img = cv.imread('opencv_resources/balls.jpeg')
hsv = cv.cvtColor(img, cv.cv2.COLOR_BGR2HSV)

L_Hue = cv.getTrackbarPos('Lower_Hue', 'Tracking')
L_Saturation = cv.getTrackbarPos('Lower_Saturation', 'Tracking')
L_Value = cv.getTrackbarPos('Lower_Value', 'Tracking')

U_Hue = cv.getTrackbarPos('Upper_Hue', 'Tracking')
U_Saturation = cv.getTrackbarPos('Upper_Saturation', 'Tracking')
U_Value = cv.getTrackbarPos('Upper_Value', 'Tracking')

lower_bound = np.array([L_Hue, L_Saturation, L_Value])
upper_bound = np.array([U_Hue, U_Saturation, U_Value])

mask = cv.inRange(hsv, lower_bound, upper_bound)
result = cv.bitwise_and(img, img, mask=mask)

cv.imshow('Original', img)
cv.imshow('MASK', mask)
cv.imshow('RESULT', result)

key = cv.waitKey(0) & 0xff
if key == 27:
    break

cv.destroyAllWindows()

`

`

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