Access to each separate channel in OpenCV

Question

I have an image with 3 channels (img) and another one with a single channel (ch1).

    Mat img(5,5,CV_64FC3);
    Mat ch1 (5,5,CV_64FC1);

I

Answer 1

A simpler one if you have a RGB with 3 channels is cvSplit() if i'm not wrong, you have less to configure... (and i think it is also well optimized).

I would use cvMixChannel() for "harder" tasks... :p (i know i am lazy).

here is the documentation for cvSplit()