Webcam (摄像头) 算子

输入

• tick: Dora tick.

输出

• 图像: 高 x 宽 x BGR array.

配置

使用 cv2 包获取摄像头图像。 摄头号可被使用 CAMERA_INDEX 配置

图描述

  - id: yolov5
    operator: 
      outputs:
        - bbox
      inputs:
        image: webcam/image
      python: ../../operators/webcam_op.py

方法

__init__()

源码

    def __init__(self):
        self.video_capture = cv2.VideoCapture(int(DEVICE_INDEX))
        self.video_capture.set(cv2.CAP_PROP_FRAME_WIDTH, OUTPUT_WIDTH)
        self.video_capture.set(cv2.CAP_PROP_FRAME_HEIGHT, OUTPUT_HEIGHT)

.on_event(...)

源码

    def on_event(
        self,
        dora_event: dict,
        send_output: Callable[[str, bytes], None],
    ) -> DoraStatus:
        if dora_event["type"] == "INPUT":
            return self.on_input(dora_event, send_output)
        return DoraStatus.CONTINUE

.on_input(...)

源码

    def on_input(
        self,
        dora_input: dict,
        send_output: Callable[[str, bytes], None],
    ):
        ret, frame = self.video_capture.read()
        if ret:
            frame = cv2.resize(frame, (OUTPUT_WIDTH, OUTPUT_HEIGHT))
            frame = cv2.cvtColor(frame, cv2.COLOR_BGR2BGRA)
            send_output(
                "image",
                pa.array(frame.ravel()),
                dora_input["metadata"],
            )
        else:
            print("could not get webcam.")
        return DoraStatus.CONTINUE