adding several images

edit

really? so, what is addweighted function?!!

I want to apply medianblur function into a sequence of frames...So, is it possible two add some frames the same as yours, then get the average of them and give it as an input to the medianBlur function?

You don't need to add frames before applying the medianBlur function. It works on each frame by assigning each pixel a value which is equal to the median of the values of the neighboring pixels. The number of neighboring pixels considered is based on the kernel size that you pass as a parameter. More details and example code here: http://docs.opencv.org/doc/tutorials/imgproc/gausian_median_blur_bilateral_filter/gausian_median_blur_bilateral_filter.html

thanks for the comment but what I mean is using some kind of Temporal Filtering..I want to use medianBlur function in temporal domain

In that case, you may add the n number of frames and take an average (assuming this is your logic) using the above answer. cv::addWeighted() helps to assign different weights while adding. For example, assigning equal weights of 0.5 to two frames will result in a typical average, whereas weighing one frame higher than another (say 0.3 for Frame1 and 0.7 for Frame 2) would give you a weighted average with 70% of the content in frame 2 appearing in the result. (http://docs.opencv.org/modules/core/doc/operations_on_arrays.html#addweighted)

Thanks a lot for your help...what I am doing is difficult for me since I am completely newbie. I edited the code, it would be appreciated if you give me some hints on what I am doing..