帮我用python写一段代码,实现用yolo检测图片里的物体
时间: 2023-06-07 15:10:23 浏览: 269
tensorflow(python)实现 YOLO v3目标检测算法
当然,我很乐意帮您编写这段代码。您需要首先安装yolo的python API,然后使用以下代码进行物体检测:
```
import cv2
import numpy as np
import argparse
# 解析参数
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", required=True, help="path to input image")
args = vars(ap.parse_args())
# 加载yolo weights和config文件
net = cv2.dnn.readNet("yolov3.weights", "yolov3.cfg")
# 读取classes
classes = []
with open("yolov3_classes.txt", "r") as f:
classes = [line.strip() for line in f.readlines()]
# 读取图片
image = cv2.imread(args["image"])
# 获取图片的宽高
(H, W) = image.shape[:2]
# 设置yolo模型需要的blob大小
blob = cv2.dnn.blobFromImage(image, 1/255.0, (416, 416), swapRB=True, crop=False)
# 设置yolo的输入层,并且输入blob
net.setInput(blob)
# 进行向前传播
layerOutputs = net.forward(net.getUnconnectedOutLayersNames())
# 定义最小置信度和非最大值抑制nms
conf_threshold = 0.5
nms_threshold = 0.4
# 定义框框、置信度、类别列表
boxes = []
confidences = []
classIDs = []
# 遍历每一个输出层
for output in layerOutputs:
# 遍历输出层中的每一个检测框
for detection in output:
# 提取置信度
scores = detection[5:]
# 提取最大置信度的物体类别
classID = np.argmax(scores)
# 拿到该物体的置信度
confidence = scores[classID]
# 将小于置信度阈值的过滤掉
if confidence > conf_threshold:
# 将检测框还原回图片大小
box = detection[0:4] * np.array([W, H, W, H])
(centerX, centerY, width, height) = box.astype("int")
# 计算检测框的左上角坐标
x = int(centerX - (width / 2))
y = int(centerY - (height / 2))
# 更新框框、置信度、类别列表
boxes.append([x, y, int(width), int(height)])
confidences.append(float(confidence))
classIDs.append(classID)
# 进行非最大值抑制,并且只保留最大置信度的框框
idxs = cv2.dnn.NMSBoxes(boxes, confidences, conf_threshold, nms_threshold)
# 如果有检测结果
if len(idxs) > 0:
# 遍历每一个框框的索引
for i in idxs.flatten():
# 提取框框坐标
(x, y) = (boxes[i][0], boxes[i][1])
(w, h) = (boxes[i][2], boxes[i][3])
# 绘制检测框和物体类别
label = "{}: {:.2f}%".format(classes[classIDs[i]], confidences[i] * 100)
cv2.rectangle(image, (x, y), (x + w, y + h), (0, 255, 0), 2)
cv2.putText(image, label, (x, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)
# 显示结果
cv2.imshow("Result", image)
cv2.waitKey(0)
```
请注意,此代码使用的是yolo v3算法。您的图片和yolo相关文件需要与代码放在同一目录下,并且需要修改相应的文件名及路径。希望对您有所帮助!
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