See more videos without downloading here:
http://blogs.mathworks.com/pick/category/video

This is the second in a series of video tutorial made by The MathWorks Applications Engineer, Doug Hull.
This thirty minute flash based video will highlight techniques such as:

Multi-window GUIs,
application data sharing,
use of pre-built file import dialogs, subfunctions,
function handles.

If you do not have the Image Processing Toolbox replace the line

Imshow(I)

With

image(I)
colormap ([0 0 0; 1 1 1])

NOTE: You will have to download the zip file to watch the video.