Displaying an image (in a specified location) over a video stream

edit

So the Question is How to copy one Image to a part of another image?

int _tmain(int argc, _TCHAR* argv[])
{
    String  FileName1="\\opencv-master\\samples\\data\\lena.jpg", 
            FileName2="\\opencv-master\\samples\\data\\opencv-logo.png";
    Mat mSrc,mSrc_Crop,mSubImage;
    Rect rtFaceROI(200,170,160,230);

    mSrc= imread(FileName1,1);
    mSubImage= imread(FileName2,1);

    if(mSrc.empty()||mSubImage.empty())
    {
        cout<<"[Error]! Invalid Input Image\n";
        return 0;
    }

    imshow("mSrc",mSrc);
    imshow("Sub Image",mSubImage);

    resize(mSubImage,mSubImage,Size(rtFaceROI.width,rtFaceROI.height));

    mSrc_Crop= mSrc(rtFaceROI);//To Set an ROI 
    mSubImage.copyTo(mSrc_Crop);

    imshow("Sub Image",mSrc);   

    waitKey();
}

Input Image

Output Image