while True loop inside a While True loop-CodePudding

Basically I need the buzzer and LED to play/light up every time it detects my face but it only does it once as of now. eg. I show my face and it plays "signed in" and the light turns on for 3 seconds once and it stops working.

About the project: we are using a usb camera on a ras pi to recognize faces and "unlock a door" currently turning on an LED for 3 seconds and a speaker will say "signed in" every time it someone's face is recognized. SQL is for attendance taking done by my classmate so I can't really explain it.

from imutils.video import VideoStream
from imutils.video import FPS  
import face_recognition
import imutils                                                                                   
import pickle                       
import time               
import cv2
import mysql.connector
from datetime import datetime,date
from playsound import playsound
from gpiozero import LED 

from time import sleep


db = mysql.connector.connect(
    host="localhost",
    user="User",
    passwd="passwd",
    database="attendancesystem")

cursor = db.cursor()    

identified.
currentname = "unauthorised"
train_model.py
encodingsP = "encodings.pickle"

print("[INFO] loading encodings   face detector...")
data = pickle.loads(open(encodingsP, "rb").read())

to my laptop
vs1 = VideoStream(src=0,framerate=30).start()
time.sleep(2.0)


# loop over frames from the video file stream
while True:
    # grab the frame from the threaded video stream and resize it
    # to 500px (to speedup processing)
    frame = vs1.read()
    frame = imutils.resize(frame, width=500)
    # Detect the fce boxes
    boxes = face_recognition.face_locations(frame)
    # compute the facial embeddings for each face bounding box
    encodings = face_recognition.face_encodings(frame, boxes)
    names = []

    # loop over the facial embeddings
    for encoding in encodings:
        # attempt to match each face in the input image to our known
        # encodings
        matches = face_recognition.compare_faces(data["encodings"],
            encoding)
        name = "Unauthorised" #if face is not recognized, then print Unknown

        # check to see if we have found a match
        if True in matches:
            # find the indexes of all matched faces then initialize a
            # dictionary to count the total number of times each face
            # was matched
            matchedIdxs = [i for (i, b) in enumerate(matches) if b]
            counts = {}

            # loop over the matched indexes and maintain a count for
            # each recognized face face
            for i in matchedIdxs:
                name = data["names"][i]
                counts[name] = counts.get(name, 0)   1

            # determine the recognized face with the largest number
            # of votes (note: in the event of an unlikely tie Python
            # will select first entry in the dictionary)
            name = max(counts, key=counts.get)

            #If someone in your dataset is identified, print their name on the screen
            if currentname != name:
                currentname = name
                print(currentname)
                #results = ("SELECT a_s.Admin_no,a_s.Name,a.clock_in FROM authorised_students a_s JOIN attendance a ON a_s.Admin_no = a.Admin_no")
                #cursor.execute(results])
                #for x in cursor:/';
                #   print(x)
                t = datetime.now()
                time = t.strftime("%H:%M:%S")
                date = date.today()
                cursor.execute("INSERT INTO Sign_in (admin_no, Date, Clock_in) VALUES (%s,%s,%s)",(currentname,date,time))
                db.commit()
                while True:
                #Buzzer
                    playsound('/home/pi/Desktop/Sound effects/Signed in.mp3')
                #LED 
                    red = LED(17)
                    red.on()
                    sleep(3)
                    red.off()
                    break

        # update the list of names
        names.append(name)

    # loop over the recognized faces
    for ((top, right, bottom, left), name) in zip(boxes, names):
        # draw the predicted face name on the image - color is in BGR
        cv2.rectangle(frame, (left, top), (right, bottom),
            (0, 255, 225), 2)
        y = top - 15 if top - 15 > 15 else top   15
        cv2.putText(frame, name, (left, y), cv2.FONT_HERSHEY_SIMPLEX,
            .8, (0, 255, 255), 2)

    # display the image to our screen
    cv2.imshow("Facial Recognition is Running", frame)
    key = cv2.waitKey(20) & 0xFF
    


    # quit when 'q' key is pressed
    if key == ord("q"):
        break

    # update the FPS counter
    #fps.update()

#hardware interrupt 



cv2.destroyAllWindows()
vs1.stop()

CodePudding user response：

The inner loop has an unconditional break, and so never iterates more than once. The outer loop has no break, so never stops.

CodePudding user response：

After the first run, you assign the value to the variable currentname, and on the next iterations of the loop, the if currentname! = name: condition will be False. Try resetting \ deleting the currentname variable before the break statement