How to get the exact count of people by face detection in python(opencv)?

edit

I am working on getting the total count of people along with gender in a sample video or webcam.

Gender identification is working well but in counting it will show the count of people in that frame but is again reset to 0.

How do I get the count accurately(i.e, count must not increment when the same person appears more than once)

Like comparing presently detected face and check if it's unique or not and then increment (Can it be done ?How to do it?)

Or by extracting all the detected faces to a folder can continuous similarity checking be done on those extracted faces and increment when new face is scanned?

or

Is there any other way by which I can get this?

This is the function which gives count, please help with the modifications for total count with unique faces detected.

def start_webcam(model_gender, window_size, window_name='live', update_time=50):
cv2.namedWindow(window_name, WINDOW_NORMAL)
if window_size:
    width, height = window_size
    cv2.resizeWindow(window_name, width, height)

video_feed = cv2.VideoCapture(0)
video_feed.set(3, width)
video_feed.set(4, height)
read_value, webcam_image = video_feed.read()


delay = 0
init = True
while read_value:
    read_value, webcam_image = video_feed.read()
    webcam_image=cv2.flip(webcam_image,1,0)
    faces = face_cascade.detectMultiScale(webcam_image)
    for normalized_face, (x, y, w, h) in find_faces(webcam_image):
      if init or delay == 0:
        init = False
        gender_prediction = model_gender.predict(normalized_face)
      if (gender_prediction[0] == 0):
          cv2.rectangle(webcam_image, (x,y), (x+w, y+h), (0,0,255), 2)
          cv2.putText(webcam_image, 'female', (x,y-10), cv2.FONT_HERSHEY_SIMPLEX, 1, (0,0,255), 2)
      else:
          cv2.rectangle(webcam_image, (x,y), (x+w, y+h), (255,0,0), 2)
          cv2.putText(webcam_image, 'male', (x,y-10), cv2.FONT_HERSHEY_SIMPLEX, 1.5, (255,0,0), 2)

    delay += 1
    delay %= 20

    cv2.putText(webcam_image, "Number of faces detected: " + str(len(faces)), (0,webcam_image.shape[0] -10), cv2.FONT_HERSHEY_TRIPLEX, 0.7,  (255,255,255), 1)
    cv2.imshow(window_name, webcam_image)
    key = cv2.waitKey(update_time)
    if key == ESC:
        break

cv2.destroyWindow(window_name)