Re: changing contrast and brightness on the fly

["Liam E. Gumley" <Liam.Gumley(at)ssec-nospam.wisc.edu>]

Simon Williams wrote:
> I'm looking for tips on how to implement an image display feature that's
> bugging me. I'm new to widget programming, trying to get up to speed
> with David Fanning's book and other helps, but any short-cuts would be
> appreciated.
> 
> The job is to display an MRI image and to be able to adjust the image
> brightness and contrast interactively, without going to any special
> widgets like sliders. The control I have in mind is to
> middle-click the image and then have drag right/left control contrast
> and drag up/down control brightness.
> 
> The plan is to replicate functionality that the end users (radiology
> folks) are already familiar with from other image viewers.  In the
> longer term plan, the display would also be re-sizable and allow
> interactive ROI drawing as well.
> 
> It sounds easy but I can't find anything similar described on the web
> etc. to use as a suitable starting point.  Question: is changing the
> contrast and brightness to be achieved by re-defining the
> color table and re-scaling the data?

The following may be of interest:

http://www.sgi.com/grafica/interp/index.html

Cheers,
Liam.
http://cimss.ssec.wisc.edu/~gumley/