#OpenCV – How to add a Pencil Sketch effect to an image 🖼️ using Python 🐍

#englishpost #codesample #effects

Hi !

Super quick post today with a cool scenario to support my TikTok videos in Spanish (I know 😀):

How to add a pencil sketch effect to an image using python and opencv

Here is the output with an original photo from my office and a new image with the pencil sketch effect:

Sample code:

	# Copyright (c) 2022
	# Author : Bruno Capuano
	# Create Time : 2022 Feb
	# Change Log :
	# - Open a local image
	# - Apply a pencil sketch effect to the image
	#
	# 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 cv2

	# open an image using opencv
	imgOriginal = cv2.imread('Office2.jpg')
	img = cv2.resize(imgOriginal, (324, 720))
	cv2.imshow('@ElBruno - Office', img)

	# get image height and width
	height, width, channels = img.shape

	img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
	img_blur = cv2.GaussianBlur(img_gray, (21, 21), 0, 0)
	img_blend = cv2.divide(img_gray, img_blur, scale=256)
	cv2.imshow('@ElBruno - Pencil Sketch', img_blend)

	# save image using opencv
	cv2.imwrite('OfficePencilSketch.jpg', img)

	# key controller
	cv2.waitKey(0)
	cv2.destroyAllWindows()