Zoom-like procedure

[Bob Fugate <rqfugate(at)mindspring.com>]

I am displaying small parts (e.g. 16x16 pixels) of images and need to zoom
regions up to a size large enough to see the relative brightness of the
pixels. The ZOOM procedure does exactly what I want, but in an interactive
mode. Does anyone know of a function or procedure or other means  that would
allow me to include this feature in my program to automatically zoom a
preselected subregion of the image? REBIN, and CONGRID resample and that is
not what I want, I just want the intensity in each original pixel to be
reproduced everywhere in a synthesized, larger pixel, ideally whose size I
can choose.
Any suggestions are greatly appreciated.

Bob Fugate