Show multiple (2,3,4,…) images in the same window in OpenCV

Question

I want to show 2, 3 or more images in the same window.

My problem is how to put the second, third image just on the right side (above, left or upper) the main image.

Answer 1

Try this code (see my comments):

Mat img = imread("lena.JPG");

CV::Mat chann[3], all; //  creating 

split(img, chann); // split an image into their color channel and n keep them inside

a 3 element array called chann

imshow("ppl", img);

hconcat(chann, 3, all); //  joining the images together in a horizontal manner, the 

array, number of array, and the destination

imshow("B :: G :: R",all);     // this just the little help i could provide