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[英]trying to use VideoCapture and imshow(), raises Assertion failed (size.width>0 && size.height>0) in cv::imshow
[英]Assertion failed (size.width>0 && size.height>0) in imshow after copying image
我有一个问题,我试图在不同的线程上显示两个图像,其中两个图像都来自同一帧,但是其中一个是原始帧的副本,另一个是原始帧的副本。 该程序将能够完美地显示原始帧,但是当具有克隆/复制图像的线程到达imshow()时,它将崩溃,并显示以下错误:“在imshow中断言失败(size.width> 0 && size.height> 0) ”。
有没有人可以帮助您? 问候。
这是获取摄像机输入的类:
CameraInput::CameraInput()
{
// Initialize capturing live feed from the camera
capture.open(0);
capture.set(CV_CAP_PROP_FRAME_WIDTH, 640);
capture.set(CV_CAP_PROP_FRAME_HEIGHT, 480);
// Couldn't get a device? Throw an error and quit
if(!capture.isOpened())
{
qDebug() << "Capture could not be opened successfully.";
}
qDebug() << "Capure =" << QThread::currentThreadId();
}
void CameraInput::captureImage()
{
capture >> frame;
if(!frame.empty())
{
emit capturedImage(&frame);
}
//qDebug() << "capture" << QThread::currentThreadId();
}
这是到达“ 发出捕获的图像(&Frame); ”时运行的函数。 这很好。
void Controll::inputImage(cv::Mat* imgIn)
{
cv::imshow("video", *imgIn);
if (processReady)
{
processReady = false;
emit image(imgIn);
}
emit requestImage();
// see how much time has elapsed
time(&end);
// calculate current FPS
++counterOrg;
sec = difftime (end, start);
fpsOrg = counterOrg / sec;
// will print out Inf until sec is greater than 0
printf("FPS Org stream = %.2f\n", fpsOrg);
}
这是达到“ 发出图像(imgIn); ”时调用的函数。
void Process::processImage(cv::Mat* img)
{
cv::Mat imgHSV = img->clone();
emit (processedImage(&imgHSV));
emit (readyForWork());
}
在下面的代码中,我们遇到一个错误,调试行打印出来,但是在imshow()上,我们得到了所提到的错误。 我们还尝试了使用复制构造函数和copyTo(),它们都产生相同的结果。
void Controll::processedImage(cv::Mat* imgIn)
{
qDebug() << "About to show thresh image...";
cv::imshow("thresh", *imgIn);
// see how much time has elapsed
time(&end);
// calculate current FPS
++counterProcessed;
sec = difftime (end, start);
fpsProcessed = counterProcessed / sec;
// will print out Inf until sec is greater than 0
printf("FPS processed stream = %.2f\n", fpsProcessed);
}
这是main.cpp:
int main()
{
int c;
// Objects
CameraInput *camera = new CameraInput();
Controll *troller = new Controll();
Process *processer = new Process();
Tracking *tracker = new Tracking();
Serial_Communication *serial = new Serial_Communication("/dev/ttyUSB0");
// Threads
QThread *t1 = new QThread;
QThread *t2 = new QThread;
QThread *t3 = new QThread;
camera->moveToThread(t1);
processer->moveToThread(t2);
tracker->moveToThread(t3);
serial->moveToThread(t3);
// Connections
QObject::connect(t1, SIGNAL(started()), camera, SLOT(captureImage()));
QObject::connect(camera, SIGNAL(capturedImage(cv::Mat*)), troller, SLOT(inputImage(cv::Mat*)));
QObject::connect(t2, SIGNAL(started()), troller, SLOT(processerReady()));
QObject::connect(troller, SIGNAL(image(cv::Mat*)), processer, SLOT(processImage(cv::Mat*)));
QObject::connect(troller, SIGNAL(requestImage()), camera, SLOT(captureImage()));
QObject::connect(processer, SIGNAL(posXposY(int,int)), tracker, SLOT(position(int,int)));
QObject::connect(tracker, SIGNAL(directionAndSpeed(int,int)), serial, SLOT(sendData(int,int)));
QObject::connect(processer, SIGNAL(readyForWork()), troller, SLOT(processerReady()));
QObject::connect(processer, SIGNAL(processedImage(cv::Mat*)), troller, SLOT(processedImage(cv::Mat*)));
// Need to add finish/clean up stuff for terminating threads.
// Starting Threads
t1->start();
t2->start();
t3->start();
// wait for key to exit
while (true) {
c = cvWaitKey(1);
if(c!=-1)
{
// Add thread termination before breaking the loop.
// If pressed, break out of the loop
break;
}
}
return 0;
}
通过完全脱离指针和引用来解决此问题。 我们尝试按照建议的方式使用引用,但最终收到错误消息:“ QObject :: connect:无法对类型为'cv :: Mat&'的参数进行排队(确保已使用qRegisterMetaType()注册了'cv :: Mat&'。) ”。 我们无法注册cv :: Mat&,但是cv :: Mat可以正常工作。
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