opencv image mixing, separate color channels, multi-channel image mixing

And calculating a weighting arrays with addWeighted function, it is to calculate the two arrays (image array) and weighted. Prototype is as follows:
void addweighted (SrCl InputArray, Double Alpha, InputArray SRC2, Double Beta, Gamma Double, outputArray DST, DTYPE = int -1);
Uploading-Image-436808.png

Two pairs of three component color channels RGB display and adjustment opencv were split and merge the
split is to separate a multi-channel array into several single channel array
merge array is combined into a plurality of single-channel multi-channel array
if to move the array to extract a specific single-channel multi-channel array, or to achieve some complex combination of channels can be used mixChannels () function