Double pointer of Mat initialization

Double pointer of Mat initialization

I am trying to make a Mat array using OpenCV. The array is to store a
number N of region of interest, and for each region I have to store the
information of the last 5 frames. I'm trying to use a double pointer to
Mat. The question is how do I initialize it? I'm trying somehting like
this:
In the header of the class: Mat *Objs_avgwB[25];
and to initialize in the source file: vseg.Objs_avgwB = new
Mat[vseg.avgw][25];