How to get raw data using OpenCV APIs

Hi all

When I am using cvCaptureFromCAM and cvQueryFrame(), it creates image frames in RGB24 format. My Logitech camera generates YUV image. My query is How to disable this YUV to RGB conversion in the OpenCV? I don't want the image in the RGB format. Neither I want to convert the image using OpenCV APIs to YUV in the code.

All I want is the raw image generated by the camera as-is. Is that possible in OpenCV? If yes then kindly guide me.

Thanks Neha

Comments

unrelated, but please stop using the deprecated c-api !

berak (Jun 21 '16)edit

@berak - Ok. Are you suggesting to use capture.open and capture.grab()?

neha_new2OpenCV (Jun 21 '16)edit

You could try to set CV_CAP_PROP_CONVERT_RGB property of your camera to false. However this not seems to work everytime, but maybe it will work for you.

Missing (Jun 21 '16)edit

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answered Jun 21 '16

berak
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first, please use cv::VideoCapture (c++), not the deprecated c-api calls.

then, you can try to set properties on the capture, like CAP_MODE_YUVY but none of them are guaranteed to succed., it all depends on your os / hardware / driver mix.

#include "opencv2/opencv.hpp"
using namespace cv;

#include <iostream>
using namespace std;

int main()
{
    VideoCapture cap(0);

    bool ok = cap.set(CAP_PROP_CONVERT_RGB, 0);
    cerr << ok << endl;


    while(cap.isOpened())
    {
        Mat f;
        cap >> f;
        if (f.empty())
        {
            cerr << "."; // older webcams might need some "warmup" ..
            continue;
        }
        imshow("ocv",f);
        if (waitKey(10)==27) break;
    }
}