Demosaicing expects 3 channels src

[leguidomanfredi]

The functions for demosaicing expects an AbstractArray{T, 3} with three dimensions.
That defeats the goal of the demosaicing operation where you want to split a single channel array containing R, G and B into a matrix with three channels.
The opencv documentation specify that the source for this function should be single channel:
https://docs.opencv.org/3.4/db/d8c/group__cudaimgproc__color.html#ga7fb153572b573ebd2d7610fcbe64166e

[leguidomanfredi]

Missreading from my side.