Whatever you want.

There are a lot of overloads for DrawImage().  Just find the one that  
suits your needs best.  For example:

    Bitmap[,] BitmapsFromBitmap(Bitmap bmpSrc, int cxDst, int cyDst)
    {
        int ccol = (bmpSrc.Width - 1) / cxDst + 1,
            crow = (bmpSrc.Height - 1) / cyDst + 1;
        Bitmap[,] rgbmpRet = new Bitmap[ccol][crow];

        for (int irow = 0; irow < crow; irow++)
        {
            for (int icol = 0; icol < ccol; icol++)
            {
                Bitmap bmpDst = new Bitmap(cxDst, cyDst);

                using (Graphics gfx = Graphics.FromImage(bmpDst))
                {
                    gfx.DrawImage(bmpSrc, 0, 0,
                        new Rectangle(icol * cxDst, irow * cyDst, cxDst,  
cyDst),
                        GraphicsUnit.Pixel);
                }

                rgbmpRet[icol, irow] = bmpDst;
            }
        }

        return rgbmpRet;
    }

Caveat: the above was just typed into the message...I didn't bother to try  
to compile or test it.  The code also makes no attempt to deal bitmaps  
that aren't an integral multiple of the size of the sub-bitmaps; if I  
recall correctly, if a source that isn't an integral multiple of the  
destination size is used, all that will happen is that the right and/or  
bottom edge of the last sub-bitmaps just won't be painted (they'll be  
black).

Finally, the above code assumes the passed in Bitmap is at least 1x1 pixel  
in size.

Pete

Stephen,

   I would use the overload specified here:

http://msdn2.microsoft.com/en-us/library/ms142040.aspx

   You just have to define the source and destination rectangles.  The
destination rectangle should be simple enough, it's just the rectangle that
defines the boundary of the whole image (the 16x16 image).