basic.py

import mediapipe as mp
import time
import cv2

cap = cv2.VideoCapture(0)

pTime = 0

mpFaceDetection = mp.solutions.face_detection
mpDraw = mp.solutions.drawing_utils
faceDetection = mpFaceDetection.FaceDetection(0.75)

while True:
    success, img = cap.read()

    imgRGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    results = faceDetection.process(imgRGB)

    if results.detections:
        for id, detection in enumerate(results.detections):
            bboxC = detection.location_data.relative_bounding_box
            ih, iw, ic = img.shape
            bbox = int(bboxC.xmin * iw), int(bboxC.ymin * ih), \
                int(bboxC.width * iw), int(bboxC.height * ih)
            cv2.rectangle(img, bbox, (255, 0, 0), 2)
            cv2.putText(img, f'{int(detection.score[0] * 100)}%',
                        (bbox[0], bbox[1] - 20), cv2.FONT_HERSHEY_PLAIN,
                        3, (0, 255, 0), 2)

    cTime = time.time()
    fps = 1 / (cTime - pTime)
    pTime = cTime
    cv2.putText(img, f'FPS: {int(fps)}', (20, 70), cv2.FONT_HERSHEY_PLAIN,
                3, (0, 255, 0), 2)

    cv2.imshow("Image", img)

    if cv2.waitKey(1) == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()