Non linear blending - How to?

Viatorus
61 ●6

Hey Community,

I want do blend two images non linear. AddWeighted can only blend two images linear. I am looking for something like this:

non linear blending

(http://graphics.cs.cmu.edu/courses/15-463/2008_fall/Lectures/blending.pdf)

The best would be, if I could use my own mask for that. I thought to use a alpha mask (explained here) but I don´t know how to get back to rgb and blend again..

Anyone an idea? Thanks in advance!

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answered Dec 20 '13

berak
32993 ●7 ●81 ●312

you could just go and interpol single cols:

Mat l(100,200,CV_8UC3,Scalar(255,0,0)); // you probably want to imread your img,
Mat r(100,200,CV_8UC3,Scalar(0,0,255)); // this is just to show the effect nicely
Mat res(l.size(),l.type());
double step = 1.0 / l.cols;
double blend = 0.0;
for ( int i=0; i<l.cols; i++ )
{
    res.col(i) = l.col(i) * blend + r.col(i) * (1.0-blend);
    blend += step;
}
imwrite("blended.png",res);
imshow("lalala",res);
waitKey();