Ich habe das Google-Beispiel auseinandergenommen (Bilddatei/Webcam), leicht angepasst und korrigiert. Das Original-Beispiel findet man online.
Aus Bilddatei
py
import cv2
import mediapipe as mp
mp_face_detection = mp.solutions.face_detection
mp_drawing = mp.solutions.drawing_utils
# For static images:
IMAGE_FILES = ["selfie.jpg"]
with mp_face_detection.FaceDetection(model_selection=1, min_detection_confidence=0.5) as face_detection:
for file in IMAGE_FILES:
image = cv2.imread(file)
# Convert the BGR image to RGB and process it with MediaPipe Face Detection.
converted = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
results = face_detection.process(converted)
# Draw face detections of each face.
if not results.detections:
continue
annotated_image = image.copy()
for detection in results.detections:
print('Nose tip:')
print(mp_face_detection.get_key_point(detection, mp_face_detection.FaceKeyPoint.NOSE_TIP))
mp_drawing.draw_detection(annotated_image, detection)
cv2.imwrite(file.split(".")[0] + '_output.png', annotated_image)
Von Webcam
py
import cv2
import mediapipe as mp
mp_face_detection = mp.solutions.face_detection
mp_drawing = mp.solutions.drawing_utils
# For webcam input:
cap = cv2.VideoCapture(0)
with mp_face_detection.FaceDetection(model_selection=0, min_detection_confidence=0.5) as face_detection:
while cap.isOpened():
(success, image) = cap.read()
if not success:
print("Ignoring empty camera frame.")
# If loading a video, use 'break' instead of 'continue'.
continue
# To improve performance, optionally mark the image as not writeable to
# pass by reference.
image.flags.writeable = False
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
results = face_detection.process(image)
# Draw the face detection annotations on the image.
image.flags.writeable = True
image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
if results.detections:
for detection in results.detections:
mp_drawing.draw_detection(image, detection)
# Flip the image horizontally for a selfie-view display.
cv2.imshow('MediaPipe Face Detection', cv2.flip(image, 1))
if cv2.waitKey(5) & 0xFF == 27:
break
cap.release()
Tipp: macOS
Das Beispiel muss Zugriff auf die Webcam haben. Thonny selbst frägt dazu im System nicht nach. Aber es gibt eine Lösung:
- gehe auf Run 👉 Run current script in terminal
- das Terminal verlangt Zugriff auf die Webcam
- erlaube dies
- starte ab jetzt immer über den Terminal