Question

所以我的代码使用我的手捕获一个特定动作的帧，唯一的问题是我需要等待我的手在帧存储之前移出。

我尝试过使用Sleep（3000），所有视频输出都会冻结3秒钟，但它会在视频输出冻结之前捕获帧，而不是在它们之后，所以基本上当我的手还在路上时。

有什么方法可以让capture >> saveImage;停止运行几秒钟？

//bools for gestures
bool bSavePic = false;
bool bSingleFrame = true;

int main(int argc, char* argv[])
{
//Following for measuring FPS
time_t startFPS, endFPS;
double fps;
int counter = 0;
double sec;
time(&startFPS);

//if we would like to calibrate our filter values, set to true.
bool calibrationMode = true;

//Matrix to store each frame of the webcam feed
Mat cameraFeed;
Mat threshold;
Mat HSV;

//Initalise count at 0 for image saving
int c = 0;

if(calibrationMode)
{
    //create slider bars for HSV filtering
    createTrackbars();
    cout << "The program is currently in calibration mode" << endl;
    cout << "this is so that HSV values can be recorded for" << endl;
    cout << "each marker." << endl;
}//if calibrationMode

//video capture object to acquire webcam feed
VideoCapture capture;
//open capture object at location zero (default location for webcam)
capture.open(2);
//When using video files.
//capture.open("My Recording1.avi");

//set height and width of capture frame
capture.set(CV_CAP_PROP_FRAME_WIDTH,FRAME_WIDTH);
capture.set(CV_CAP_PROP_FRAME_HEIGHT,FRAME_HEIGHT);

//start an infinite loop where webcam feed is copied to cameraFeed matrix
//all of our operations will be performed within this loop
while(capture.isOpened())
{
    //store image to matrix
    capture.read(cameraFeed);

    //After each frame in captured measure FPS
    time(&endFPS);
    ++counter;        
    sec = difftime (endFPS, startFPS);      
    fps = counter / sec;
    printf("FPS = %.2f\n", fps);

    //convert frame from BGR to HSV colorspace
    cvtColor(cameraFeed,HSV,COLOR_BGR2HSV);

    if(calibrationMode==true)
    {
    //if in calibration mode, we track objects based on the HSV slider values.

    inRange(HSV,Scalar(H_MIN,S_MIN,V_MIN),Scalar(H_MAX,S_MAX,V_MAX),threshold);
    morphOps(threshold);
    //Show thresholded image
    imshow(windowName2,threshold);
    trackFilteredObject(threshold,HSV,cameraFeed);

    }else{

    }

    //Following function checks if distance is <100
    //Uses another one time bool flag, bSingleFrame, which is initially set to true
    //Checks if bSingleFrame && bSavePic are true, if so captures a frame
    //bSingleFrame is then changed to false if the distance is still <100
    //Once the distance is >100, bSingleFrame is changed back to true, and another frame can be captured
    //Means only one frame is captured when the conditions are met

    //If distance<100
    if (bSavePic == true)
    {
        if (bSingleFrame == true)
        {
            //Display that the frame captured is being saved
            putText(cameraFeed,"Saving Image",Point(50,70),1,1,Scalar(0,0,255),1);
                            //*****SLEEP FUNCTION*****
                            Sleep(3000);
            //Matrix to store image for saving
            Mat saveImage;

            capture >> saveImage;
            //string stream initialised through each passing of while loop
            stringstream ssFileName;
            //Directory to save image & File name based on frame captured 0++
            ssFileName << "gestureimages/Image-" << c << ".png";        
            ssFileName >> sFileName;

            //If file exists function       ***NEEDS MODIFIED***
            if(!fileExists == 0)
            //{
            //  //need file name search function, find number after image
            //  //start c at this number
            //  c++;
            //  stringstream ssFileName;                    //string stream initialised through each passing of while loop
            //  ssFileName << "Image-" << c << ".jpg";      //File name based on frame captured 0++
            //  ssFileName >> sFileName;
            //}

        //check if frame captured is stored in matrix
        if(!saveImage.empty())                          
        {
            cout << "Frame captured." << endl;
            //Save frame
            imwrite(sFileName.c_str(), saveImage);
            saveImage.release();                        
            c++;
            //If distance is still <100 switch bSingleFrame
            if (bSavePic == true)   
            {
                bSingleFrame = false;
            }

            Mat readImage;
            //Load saved frame form file
            readImage = imread(sFileName.c_str(),CV_LOAD_IMAGE_COLOR);  
            //show captured frame in new window
            imshow(windowName4, readImage);             
        }else{
            cout << "Error, could not capture frame to save." << endl;
        }//if(!saveImage.empty())
        }//bSingleFrame
    }//ifbSavePic
    if (bSavePic == false)
        {
            //if distance back >100 can capture another frame
            bSingleFrame = true;
        }

    //Display webcam output 
    imshow(windowName,cameraFeed);
    //Display thresholded output
    imshow(windowName2,threshold);

    //delay 30ms so that screen can refresh.
    //image will not appear without this waitKey() command
    waitKey(30);
}//while

return 0;
}//main

这只是我的主要功能的一小部分，我的完整代码可用here

Answer 1

首先尝试使用sleep并手动拨打grab。这应确保仅在一定时间后捕获图像。

如果这应该失败，请尝试阅读两张图片，只保留第二张图片。（这不好，但无论如何你都不是时间依赖）。

如果也失败，请检查您的睡眠功能是否有异常行为;）

延迟帧捕获opencv

1 个答案: