logo

OpenCV 人脸检测

王哲峰 / 2022-08-31

目录

目标简介

目标: 使用 Flask API 部署 OpenCV App 进行人脸检测 实现技术:

img

项目结构

img

Flask App

from flask import Flask, render_template, Response
import cv2

app = Flask(__name__)

def capture_by_frames():
    global camera
    camera = cv2.VideoCapture(0)
    while True:
        # read the camera frame
        success, frame = camera.read()
        detector = cv2.CascadeClassifier("Haarcascades/haarcascade_frontalface_default.xml")
        faces = detector.detectMultiScale(frame, 1, 2, 6)
        # draw the rectangle around each face
        for (x, y, w, h) in faces:
            cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 3)
        
        ret, buffer = cv2.imencode(".jpg", frame)
        frame = buffer.tobytes()
        yield(b"--frame\r\n"
              b"Content-Type: image/jpeg\r\n\r\n" + frame + b"\r\n")

@app.route("/")
def index():
    return render_template("index.html")

@app.route("/start", methods = ["POST"])
def start():
    return render_template("index.html")

@app.route("/stop", methods = ["POST"])
def stop():
    if camera.isOpened():
        camera.release()
    return render_template("stop.html")

@app.route("./video_capture")
def video_capture():
    return Response(capture_by_frames(), mimetype = "multipart/x-mixed-replace; boundary=frame")


if __name__ == "__main__":
    app.run(debug = True, use_reloader = False, port = 8000)

Web 页面

index.html

<!DOCTYPE html>
<html>
 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
 <title>Dharmaraj - Face Detection</title>
<style>
h2
{
padding-bottom:20px;
font-weight: 600;
font-size: 3.2em
}
img {
    pointer-events: none;
}
</style>
  <body>
    <div class="container"><center><h2>Face Detection</h2></center>
      <div class="col-lg-offset-2 col-lg-8">
        <center><form  class="form-inline" action = "/stop" method = "post" enctype="multipart/form-data">          
          <input type = "submit" class="btn btn-danger btn-md btn-block" value="Stop">
             </form></center>
                <center><form  class="form-inline" action = "/start" method = "post" enctype="multipart/form-data">          
          <input type = "submit" class="btn btn-success btn-md btn-block" value="Start">
             </form></center><br></div>
                    <div class="col-lg-offset-2 col-lg-8">
         <img src="{{ url_for('video_capture') }}" width="100%">
        </div></div>
    </body>
</html>

stop.html

<!DOCTYPE html>
<html>
 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
 <title>Dharmaraj - Face Detection</title>
<style>
h2
{
padding-bottom:20px;
font-weight: 600;
font-size: 3.2em
}
img {
    pointer-events: none;
}
</style>
  <body>
    <div class="container">
    <center><h2>Face Detection</h2></center>
            <div class="col-lg-offset-2 col-lg-8">
                  <center><form  class="form-inline" action = "/stop" method = "post" enctype="multipart/form-data">          
          <input type = "submit" class="btn btn-danger btn-md btn-block" value="Stop">
                       </form></center>
                <center><form  class="form-inline" action = "/start" method = "post" enctype="multipart/form-data">          
          <input type = "submit" class="btn btn-success btn-md btn-block" value="Start">
             </form></center><br>                
            </div></div>
    </body>
</html>

运行 Flask App

$ flask app

参考