Creating an ROI (Region of Interest)

[Jerry Mulchin <jmulchin astroguy com>]

I'm looking for a way to create a Region of Interest in an image. I want to be able create
a rectangle that I can change the shape as I drag the mouse, and I want to be able to 
place the ROI anywhere in the image. I would like the lines generated for the rectangle
to be dashed or translucent, not solid lines if at all possible as it becomes a distraction.
I also need to have the dimensions of the rectangle returned so that the area of the ROI 
can be used to mark the processing area.

I've looked at all the Gtk+ stuff for creating rectangles and they all require predefined X/Y
values to create the box. I need the box to be enlarged or shrunk by using the mouse
directly. It can start out as a small rectangle, but it has to be changable by using the
mouse.

Can anyone help me with code or URL locations that explain how to do this using Gtk+.

Thanks in Advance

Jerry Mulchin    Amateur Radio Call  -  N7EME
Programmer, Amateur Astronomer, Ham Radio
e-mail (home) - jmulchin astroguy com
e-mail (work) - jmulchin cisco com
Astronomy Web Page  http://www.astroguy.com
"It is never wrong to ask a question, it is always wrong to be ignorant."