Im using this code to detect teh 468 facial landmarks from a face:

import cv2
import mediapipe as mp
import time

cap = cv2.VideoCapture(0)
pTime = 0

mpDraw = mp.solutions.drawing_utils
mpFaceMesh = mp.solutions.face_mesh
faceMesh = mpFaceMesh.FaceMesh(max_num_faces=2)
drawSpec = mpDraw.DrawingSpec(thickness=1, circle_radius=2)

while True:
    success, img = cap.read()
    imgRGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
    results = faceMesh.process(imgRGB)
    if results.multi_face_landmarks:
        for faceLms in results.multi_face_landmarks:
            mpDraw.draw_landmarks(img, faceLms, mpFaceMesh.FACEMESH_CONTOURS,
                                  drawSpec,drawSpec)
            for id,lm in enumerate(faceLms.landmark):
                #print(lm)
                ih, iw, ic = img.shape
                x,y = int(lm.x*iw), int(lm.y*ih)
                print(id,x,y)

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

When I run this script, I can see the facial landmarks printed on my face, but what I want to achieve is that I display the facial landmarks on a black background without actually showing a face.

How can I achieve that?

CodePudding user response：

You can create an image with dark (black) pixels (0) of the same dimensions of the frame captured by the camera. And carry out your drawings there

# create the dark image
black = np.zeros(img.shape , np.uint8)

# Replace the `img` with `black` while drawing the landmarks
mpDraw.draw_landmarks(black, faceLms, mpFaceMesh.FACEMESH_CONTOURS, drawSpec,drawSpec)

# Display the result
cv2.imshow("Result", black)