Raspberry Pi CSI 攝像頭到 USB 網絡攝像頭 Python

Question

我正在嘗試使用https://github.com/ageitgey/face_recognition中的示例

用於 Raspberry Pi 上的人臉檢測。

這是“ facerec_on_raspberry_pi.py ”代碼：

# This is a demo of running face recognition on a Raspberry Pi.
# This program will print out the names of anyone it recognizes to the console.

# To run this, you need a Raspberry Pi 2 (or greater) with face_recognition and
# the picamera[array] module installed.
# You can follow this installation instructions to get your RPi set up:
# https://gist.github.com/ageitgey/1ac8dbe8572f3f533df6269dab35df65

import face_recognition
import picamera
import numpy as np

# Get a reference to the Raspberry Pi camera.
# If this fails, make sure you have a camera connected to the RPi and that you
# enabled your camera in raspi-config and rebooted first.
camera = picamera.PiCamera()
camera.resolution = (320, 240)
output = np.empty((240, 320, 3), dtype=np.uint8)

# Load a sample picture and learn how to recognize it.
print("Loading known face image(s)")
obama_image = face_recognition.load_image_file("obama_small.jpg")
obama_face_encoding = face_recognition.face_encodings(obama_image)[0]

# Initialize some variables
face_locations = []
face_encodings = []

while True:
    print("Capturing image.")
    # Grab a single frame of video from the RPi camera as a numpy array
    camera.capture(output, format="rgb")

    # Find all the faces and face encodings in the current frame of video
    face_locations = face_recognition.face_locations(output)
    print("Found {} faces in image.".format(len(face_locations)))
    face_encodings = face_recognition.face_encodings(output, face_locations)

    # Loop over each face found in the frame to see if it's someone we know.
    for face_encoding in face_encodings:
        # See if the face is a match for the known face(s)
        match = face_recognition.compare_faces([obama_face_encoding], face_encoding)
        name = "<Unknown Person>"

        if match[0]:
            name = "Barack Obama"

        print("I see someone named {}!".format(name))

代碼在 CSI 攝像頭上運行良好，但如何更改為使用 USB 網絡攝像頭？

謝謝

Answer 1

您可以直接使用 opencv API。

而不是像這樣創建 PiCamera object：

camera = picamera.PiCamera()
camera.resolution = (320, 240)
output = np.empty((240, 320, 3), dtype=np.uint8)

嘗試：

import cv2
camera = cv2.VideoCapture(0) # 0 is the first camera

然后，在讀取圖像時，替換：

camera.capture(output, format="rgb")

和：

_, output = camera.read() # To read the image in the camera native resolution
output = cv2.resize(output, (320, 240)) #To get the image in the same size as expected