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Raspberry Pi 3 Cookbook for Python Programmers - Third Edition
book

Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

by Steven Lawrence Fernandes, Tim Cox
April 2018
Beginner content levelBeginner
552 pages
13h 58m
English
Packt Publishing
Content preview from Raspberry Pi 3 Cookbook for Python Programmers - Third Edition

How to do it...

  1. Import the necessary packages:
import cv2 
import numpy as np 
  1. Load the face cascade file:
frontalface_cascade= cv2.CascadeClassifier('haarcascade_frontalface_alt.xml') 
  1. Check whether the face cascade file has been loaded:
if frontalface_cascade.empty(): 
  raiseIOError('Unable to load the face cascade classifier xml file') 
  1. Initialize the video capture object:
capture = cv2.VideoCapture(0) 
  1. Define the scaling factor:
scale_factor = 0.5 
  1. Perform the operation until the Esc key is pressed:
# Loop until you hit the Esc key 
while True: 
  1. Capture the current frame and resize it:
  ret, frame = capture.read() 
  frame = cv2.resize(frame, None, fx=scale_factor, fy=scale_factor,  
            interpolation=cv2.INTER_AREA) 
  1. Convert the image ...
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Publisher Resources

ISBN: 9781788629874Supplemental Content