#OpenCV – Convert camera feed 🎦 to Grayscale and resalt Blue 🔵 and Red ❤️

Hi !

A new twist on these days demos, this time:

• Open a camera feed
• Convert each frame to grayscale
• Use a hue mask to resalt colors, Blue and Red

Here is a live sample from my office.

Note: I created a mask that identifies the Captain America shield, SpyderGwen poster and Ahsoka frame, but it’s missing the Canada flag 🍁 ! Still, my guitar and working desk are converted to grayscale.

Another funny scenario !

And the sample code:

	# Copyright (c) 2022
	# Author : Bruno Capuano
	# Create Time : 2022 June
	# Change Log :
	# - Open the camera feed
	# - Convert the camera feed to Grayscale
	# - Resalt a specific colors >> RED and BLUE
	#
	# The MIT License (MIT)
	#
	# Permission is hereby granted, free of charge, to any person obtaining a copy
	# of this software and associated documentation files (the "Software"), to deal
	# in the Software without restriction, including without limitation the rights
	# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	# copies of the Software, and to permit persons to whom the Software is
	# furnished to do so, subject to the following conditions:
	#
	# The above copyright notice and this permission notice shall be included in
	# all copies or substantial portions of the Software.
	#
	# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	# THE SOFTWARE.
	import numpy as np
	import cv2
	cap = cv2.VideoCapture(0)
	while True:
	# read image
	ret, img = cap.read()
	img = cv2.resize(img, (320, 240))
	#convert the BGR image to HSV colour space
	hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
	#obtain the grayscale image of the original image
	gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
	# set the bounds for the red and blue hue
	lower_red = np.array([25,37,40])
	upper_red = np.array ([255, 255, 255])
	# create a mask using the bounds set
	mask = cv2.inRange(hsv, lower_red, upper_red)
	# create an inverse of the mask
	mask_inv = cv2.bitwise_not(mask)
	# Filter only the red colour from the original image using the mask(foreground)
	res = cv2.bitwise_and(img, img, mask=mask)
	# Filter the regions containing colours other than red from the grayscale image(background)
	background = cv2.bitwise_and(gray, gray, mask = mask_inv)
	# convert the one channelled grayscale background to a three channelled image
	background = np.stack((background,)*3, axis=-1)
	# add the foreground and the background
	img_ca = cv2.add(res, background)
	cv2.imshow('@ElBruno - Office', img)
	cv2.imshow('@ElBruno - Captain America', img_ca)
	if cv2.waitKey(1) & 0xFF == ord('q'):
	break
	# close camera
	cap.release()
	cv2.destroyAllWindows()

view raw cameratograyscaleresaltredandblue.py hosted with ❤ by GitHub

Happy coding!

Greetings

El Bruno

More posts in my blog ElBruno.com.

---