QT + OPENCV Label Pixmap

[Stevendragoes]

Hello all again. I have a webcamera which gives in input and i used OpenCV to draw the frames and show in one label (Did the conversions and etc). I want to filter Blue colors from the webcam and display in another Label. However, pixmap overrides whenever i try to move. I use it in a slot to update every QTimer Count.
Heres the code.

onlinecam >> onlineframes;
        currframes = QString::number(currframe);
        cv::cvtColor(onlineframes, hsv, cv::COLOR_BGR2HSV);
        cv::inRange(hsv, cv::Scalar(110,50,50), cv::Scalar(130, 255, 255), mask);
        cv::bitwise_and(onlineframes, onlineframes ,res, mask);
        cv::cvtColor(res, blue_image, cv::COLOR_BGR2RGB);
        //ui->textEdit->append("Current Frame: " + currframes);
        cv::cvtColor(onlineframes,  onlineframes, cv::COLOR_BGR2RGB);
        
        // cv::resize(onlineframes,onlineframes,cv::Size(vheight,vwidth), 0, 0, cv::INTER_AREA);
        QImage imdisplay((uchar*)onlineframes.data, onlineframes.cols, onlineframes.rows, QImage::Format_RGB888);
        QImage filtered_image((uchar*)blue_image.data, blue_image.cols, blue_image.rows, QImage::Format_RGB888);
        ui->binary_display->setPixmap(QPixmap::fromImage(filtered_image));
        
        ui->image_display->setPixmap(QPixmap::fromImage(imdisplay));

The resulting video looks like this.

I stopped the video cam because I don't want to show my picture. and I have a blue pen and waved around the camera. However, the resulting filtered image just overrides the previous pixmap that is set. Any Idea how to solve it?

[Stevendragoes]

@Pl45m4 @mrdebug I have solved it by using setTo. Turns out it was an opencv issue

[mrdebug]

Sorry but it is not clear, maybe my english is not so fluent.
Do you want to merge more images in one?

[Pl45m4]

@Stevendragoes

So the problem is, that you get the blue parts from your previous frame in your current and next frame?!
Try to clear your cv::Mat onlineframes before setting new data to pixmap.

        // This might work or else try to fill with zeros if it doesnt work 
        onlineframes.release();
        
        // then populate cv::Mat with current frame data
        onlinecam >> onlineframes;
       
        currframes = QString::number(currframe);
        cv::cvtColor(onlineframes, hsv, cv::COLOR_BGR2HSV);
        cv::inRange(hsv, cv::Scalar(110,50,50), cv::Scalar(130, 255, 255), mask);
        cv::bitwise_and(onlineframes, onlineframes ,res, mask);
        cv::cvtColor(res, blue_image, cv::COLOR_BGR2RGB);
        //ui->textEdit->append("Current Frame: " + currframes);
        cv::cvtColor(onlineframes,  onlineframes, cv::COLOR_BGR2RGB);
        
        // cv::resize(onlineframes,onlineframes,cv::Size(vheight,vwidth), 0, 0, cv::INTER_AREA);
        QImage imdisplay((uchar*)onlineframes.data, onlineframes.cols, onlineframes.rows, QImage::Format_RGB888);
        QImage filtered_image((uchar*)blue_image.data, blue_image.cols, blue_image.rows, QImage::Format_RGB888);
        ui->binary_display->setPixmap(QPixmap::fromImage(filtered_image));

[Stevendragoes]

@Pl45m4 Hello, Yes i get the problem of the previous frame existing in my current frame. Maybe filling it with zeros will do the trick I am still trying to figure it out

[Stevendragoes]

@mrdebug No no. I have the problem of my previous frames exisiting in my current frame.
Hence, I got these movement frames

[Stevendragoes]

@Pl45m4 @mrdebug I have solved it by using setTo. Turns out it was an opencv issue