Extracting the Y, Cb, Cr from a Mat in c++ and create a Mat with only the Y values

Question

I have two videos which I want to fuse. I plan to take the visible light video, capture frames, and convert the frames to YUV. Before fusing this with the IR video, I want to extract the Y component, put it in another image(variable) of type Mat of the same size and fuse that with the luminance of IR frame. After fusion, I want to put the Cb and Cr back to get the colors.

I saw this link: Getting the Y and Cb , Cr values of a frame in openCV c++

But I couldn't figure out how I can create my own matrices with this method of extracting Y, Cb and Cr.

Any ideas how I can do this?

Answer 1

look at split() and merge

Mat vis_img; // from cam

Mat ycrcb;
cvtColor( vis_img, ycrcb, CV_BGR2YCRCB ); // am i right assuming rgb input even ?

Mat channels[3];
split( ycrcb, channels );

// y is channels[0], cb is channels[1], cr, well...

// some operations on channels later..
// once you 'fused' your luminance channels into one, you can re-assemble the image
// from the channels:

Mat new_channels[3] = { lum_fused, channels[1], channels[2] };

Mat new_ycrcb;
merge( new_channels, new_ycrcb, 3 );