Tiny yolo v4 dnn模块opencv未检测到

import cv2
import numpy as np

# 加载模型
net = cv2.dnn.readNetFromDarknet('yolov4-tiny.cfg', 'yolov4-tiny.weights')
layer_names = net.getLayerNames()
output_layers = [layer_names[i[0] - 1] for i in net.getUnconnectedOutLayers()]

# 读取图像
image = cv2.imread('test.jpg')
height, width, channels = image.shape

# 图像预处理
blob = cv2.dnn.blobFromImage(image, 1/255.0, (416, 416), swapRB=True, crop=False)
net.setInput(blob)

# 前向传播
outputs = net.forward(output_layers)

# 后处理
conf_threshold = 0.5
nms_threshold = 0.4
for output in outputs:
    for detection in output:
        scores = detection[5:]
        class_id = np.argmax(scores)
        confidence = scores[class_id]
        if confidence > conf_threshold:
            center_x = int(detection[0] * width)
            center_y = int(detection[1] * height)
            w = int(detection[2] * width)
            h = int(detection[3] * height)
            x = int(center_x - w / 2)
            y = int(center_y - h / 2)
            cv2.rectangle(image, (x, y), (x + w, y + h), (0, 255, 0), 2)

# 显示结果
cv2.imshow("Image", image)
cv2.waitKey(0)
cv2.destroyAllWindows()