yolov8调用电脑摄像头

要使用YOLOv8调用电脑摄像头，需要先安装OpenCV和YOLOv8，并编写相应的代码。以下是一个简单的示例代码：

import cv2
import numpy as np

# 加载YOLOv8模型
net = cv2.dnn.readNet("yolov8.weights", "yolov8.cfg")

# 获取摄像头
cap = cv2.VideoCapture(0)

while True:
    # 读取摄像头帧
    ret, frame = cap.read()

    # 对帧进行预处理
    blob = cv2.dnn.blobFromImage(frame, 1/255, (416, 416), swapRB=True, crop=False)

    # 将预处理后的帧输入到YOLOv8模型中进行检测
    net.setInput(blob)
    outs = net.forward(net.getUnconnectedOutLayersNames())

    # 处理检测结果
    class_ids = []
    confidences = []
    boxes = []
    for out in outs:
        for detection in out:
            scores = detection[5:]
            class_id = np.argmax(scores)
            confidence = scores[class_id]
            if confidence > 0.5:
                center_x = int(detection[0] * frame.shape[1])
                center_y = int(detection[1] * frame.shape[0])
                w = int(detection[2] * frame.shape[1])
                h = int(detection[3] * frame.shape[0])
                x = center_x - w // 2
                y = center_y - h // 2
                class_ids.append(class_id)
                confidences.append(float(confidence))
                boxes.append([x, y, w, h])

    # 绘制检测结果
    indices = cv2.dnn.NMSBoxes(boxes, confidences, 0.5, 0.4)
    for i in indices:
        i = i[0]
        box = boxes[i]
        x, y, w, h = box
        cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)

    # 显示帧
    cv2.imshow("frame", frame)

    # 按下q键退出循环
    if cv2.waitKey(1) == ord('q'):
        break

# 释放摄像头并关闭窗口
cap.release()
cv2.destroyAllWindows()