Opencv——Python face recognition demo

Install

Environment: python3.6.5

opencv version: 3.4.1.15

Extension pack version: 3.4.1.15

 

 It is best to open a virtual environment to install. What is a virtual environment? In a word, it is to prevent dependency conflicts in an environment. Thereby opening up another sub-environment. Create a virtual environment method: I can directly choose when I create a new project on pycharm. Other creation methods are Baidu.

If you don’t know the virtual environment yet, just move here

face recognition code

import cv2

if __name__ == '__main__':
    img = cv2.imread("3.jpg")
    img = cv2.resize(img, None, fy=0.5, fx=0.5)
    face_data = cv2.CascadeClassifier("haarcascade_frontalface_alt.xml")
    faces = face_data.detectMultiScale(img)
    for x, y, w, h in faces:
        cv2.rectangle(img, pt1=(x, y), pt2=(x + w, y + h), color=(0, 0, 255))
    cv2.imshow("co", img)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

 Renderings:

mosaic code

import cv2
import numpy as np

if __name__ == '__main__':
    img = cv2.imread("3.jpg")
    img = cv2.resize(img, None, fy=0.5, fx=0.5)
    face_data = cv2.CascadeClassifier("haarcascade_frontalface_alt.xml")
    faces = face_data.detectMultiScale(img)
    for x, y, w, h in faces:
        mask = None
        mask = img[y:y+h, x:x+w]
        mask = mask[::6, ::6]
        mask = np.repeat(mask, 6, axis=0)
        mask = np.repeat(mask, 6, axis=1)
        img[y:y+h, x:x+w] = mask[:h, :w]
    cv2.imshow("co", img)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

renderings

 

 Face recognition code in video

import cv2

if __name__ == '__main__':
    cap = cv2.VideoCapture(0)
    while cap.isOpened():
        ret, img = cap.read()
        face_data = cv2.CascadeClassifier("haarcascade_frontalface_alt.xml")
        faces = face_data.detectMultiScale(img)
        for x, y, w, h in faces:
            cv2.rectangle(img, pt1=(x, y), pt2=(x + w, y + h), color=(0, 0, 255))
        cv2.imshow("video", img)
        if cv2.waitKey(10) == ord('q'):
            break
    cv2.destroyAllWindows()

focus

Use the haarcascade_frontalface_alt.xml trained by others in opencv in github.

A video is equivalent to a photo

Color sorting in opencv is BGR

If you want to modify the accuracy of face recognition, you can adjust the scaleFactor default 1.1 and minNeighbors default 3 in the detectMultiScale method