[M4IF Technotes] Re: GMC concept

[Kris Huber]

Hi Kasturi,
> Also I was wondering if this equation corresponds to a zoom-in.
> X=0.5i + W/4; Y=0.5j + H/4 without change in shape.

Yes, according to my understanding it is a zoom-in.  This assumes that (i,j)
are coordinates of the current frame, (X, Y) are coordinates of the
reference frame, and that both are in the same units of full-pixel samples.
In that case the zoom would be a very fast one (a factor of 2 enlargement in
a single frame).  The offset would keep the picture center unchanged for
that amount of zoom.
Regards,
Kris