You can try the code given below

CODE :

# Python program for Detection of a

# specific color(blue here) using OpenCV with Python

import cv2

import numpy as np

# Webcamera no 0 is used to capture the frames

cap = cv2.VideoCapture(0)

# This drives the program into an infinite loop.

while(1):

# Captures the live stream frame-by-frame

_, frame = cap.read()

# Converts images from BGR to HSV

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

lower_red = np.array([110,50,50])

upper_red = np.array([130,255,255])

# Here we are defining range of bluecolor in HSV

# This creates a mask of blue coloured

# objects found in the frame.

mask = cv2.inRange(hsv, lower_red, upper_red)

# The bitwise and of the frame and mask is done so

# that only the blue coloured objects are highlighted

# and stored in res

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

cv2.imshow('frame',frame)

cv2.imshow('mask',mask)

cv2.imshow('res',res)

# This displays the frame, mask

# and res which we created in 3 separate windows.

k = cv2.waitKey(5) & 0xFF

if k == 27:

break

# Destroys all of the HighGUI windows.

cv2.destroyAllWindows()

# release the captured frame

cap.release()

Anoop A Nair thank you for your response and the code. I have tried these steps and it detects all the blue objects present in the frame. I want to detect a particular object not all blue objects.

Aparna Sathya Murthy and Anoop A Nair please see the attached picture. Here you can see that it detect both the objects but i want to detect only the first object. Please help

Mudassir Ejaz for detecting the first object which I suppose is a cylinder, You need to train a Haar Cascade. It's the easiest way to execute your task.

Tutorial for training the Haar cascade :

https://medium.com/@dikshitkathuria1803/training-your-own-cascade-classifier-detector-opencv-9ea6055242c2