opcv图像捕捉

 # 加载，检测对象
 net=cv2.dnn.readNet("./yolov3.weights", "./yolov3.cfg")
 #用blob来检测
 blob=cv2.dnn.blobFromImage(frame,1/255,(320,320),(0,0,0),True,crop=False)       
 net.setInput(blob)
 #检测
 outs=net.forward(output_layers)
 # Non-max Suppression
 indexes=cv2.dnn.NMSBoxes(boxes,confidences,0.4,0.6)

 #打开视频
 cap = cv2.VideoCapture('./video.mp4')
 #保存视频
 out_video = cv2.VideoWriter('human.avi', cv2.VideoWriter_fourcc(*'MJPG'), 15., (640,480))
 out_video.write(frame)

 #捕捉一帧
 ret, frame = cap.read()
 #调整大小
 frame = cv2.resize(frame, (640, 480))
 #帧图片的尺寸
 height,width,channel = frame.shape
 #画矩形
 cv2.rectangle(frame,(x,y),(x+w,y+h),color,2)
 #标注文字
 cv2.putText(frame,label+" "+str(round(confidences[i],3)),(x,y-5),font,1, color, 1)
 #显示图像
 cv2.imshow("Detected_Images",frame)

 //c++
     //拷贝frame (cv::Mat)
     img.copyTo(out);
     //画圆
     cv::circle(out, cv::Point(100,100),5,cv::Scalar(255,0,0),2);
 
     //摄像头对象工作正常
     if (!capture.isOpened())
         return 1;
     //获取帧率
     double rate= capture.get(cv::CAP_PROP_FPS);
     
     cv::Mat frame;
     cv::namedWindow("Extracted Frame");

 https://docs.opencv.org/master/d6/d00/tutorial_py_root.html

显示视频文件

 cap.release()
 out.release()
 cv.destroyAllWindows()

numpy.argmax

 numpy.argmax(a, axis=None, out=None)[source]
 Returns the indices of the maximum values along an axis.

opcv图像捕捉

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