# Overlaying/merging two (and more) YUV images in OpenCV [closed]

I investigated and stripped down my previous question (http://answers.opencv.org/question/42201/is-there-a-way-to-avoid-conversion-from-yuv-to-bgr/). I want to overlay few images (format is YUV) on the resulting, bigger image (think about it like it is a canvas) and send it via network library (OPAL) forward without converting it to to BGR.

Here is the code:

    Mat tYUV;
Mat tClonedYUV;
Mat tBGR;
Mat tMergedFrame;
int tMergedFrameWidth = 1000;
int tMergedFrameHeight = 800;
int tMergedFrameHalfWidth = tMergedFrameWidth / 2;

tClonedYUV = tYUV.clone();

tMergedFrame = Mat(Size(tMergedFrameWidth, tMergedFrameHeight), tYUV.type(), cv::Scalar(0, 0, 0));
tYUV.copyTo(tMergedFrame(cv::Rect(0, 0, tYUV.cols > tMergedFrameWidth ? tMergedFrameWidth : tYUV.cols, tYUV.rows > tMergedFrameHeight ? tMergedFrameHeight : tYUV.rows)));
tClonedYUV.copyTo(tMergedFrame(cv::Rect(tMergedFrameHalfWidth, 0, tYUV.cols > tMergedFrameHalfWidth ? tMergedFrameHalfWidth : tYUV.cols, tYUV.rows > tMergedFrameHeight ? tMergedFrameHeight : tYUV.rows)));

namedWindow("merged frame", 1);
imshow("merged frame", tMergedFrame);
waitKey(10);


The result of above code looks like this:

I guess the image is not correctly interpreted, so the pictures stay black/white (Y component) and below them, we can see the U and V component. There are images, which describes the problem well (http://en.wikipedia.org/wiki/YUV):

Is there a way for these values to be correctly read? I guess I should not copy the whole images (their Y, U, V components) straight to the calculated positions. The U and V components should be below them and in the proper order, am I right?

edit retag reopen merge delete