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### Mat to raw Image

Hello,

I am having trouble writing a raw image from a Mat. I am using OpenCV 2.3.1. I have seen plenty of replies for the inverse operation (raw to Mat) but not Mat to raw. I am not even sure it is possible the way I do it since no headers are set.

The following code opens a video, and saves the 10 first frames into files. When I try to open those file with XNview (for example), I get a black and striped image. Clearly not the expected image. The .raw file starts with plenty of 00 00 00 00 before the real content. I cannot figure out what I am missing. DO I need to add headers ?

Here is the code :

int main( int argc , char *argv[] )
{
unsigned long lFrameId = 0;

// open video file
string mediaPath = "/home/videos/film.mp4";
VideoCapture captureV;
Mat frame;

captureV.open(mediaPath);

if( !captureV.isOpened() )
{
cerr << "capture error" << endl;
exit(1);
}

// set media parameters
captureV.set(CV_CAP_PROP_CONVERT_RGB, true);

while (lFrameId < 10
{

int rows = frame.rows;      // 880)
int cols = frame.cols;      // 720
uchar* buffer = frame.data; // 8-bit pixel

// Write frame data into raw file
ostringstream filename;
filename << "Frame_" << lFrameId << ".raw";
std::ofstream outfile (filename.str().c_str(), ios::out | ios::binary);
outfile.write ((char*)(buffer), frame.total());  // In byte so frame.total() should be enough ?
outfile.close();

++lFrameId;
}

return 0;
}