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changing contrast and brightness on the fly [message #25432]

Fri, 15 June 2001 17:13

Simon Williams
Messages: 5
Registered: October 1996

Junior Member

Greetings,

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 one or more grayscale MRI images (mostly small,
256 pixels squared is common) and then to be able to adjust the image
brightness and contrast interactively, without going to any special
widgets like sliders. The functionality 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.

The functionality I have in mind is to middle-click the image and then
have drag right/left control contrast and drag up/down control
brightness.

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
(familiar to me) contrast and brightness equivalent to re-defining the
color table and re-scaling the data (more often discussed with color
images). What parameters really define contrast and brightness?

Thanks for any help you can offer,

Simon Williams

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[Message index]

		changing contrast and brightness on the fly By: Simon Williams on Fri, 15 June 2001 17:13
		Re: changing contrast and brightness on the fly By: david[2] on Fri, 15 June 2001 19:55
		Re: changing contrast and brightness on the fly By: david[2] on Fri, 15 June 2001 19:43
		Re: changing contrast and brightness on the fly By: Ken Mankoff on Fri, 15 June 2001 19:24
		Re: changing contrast and brightness on the fly By: Richard Tyc on Mon, 18 June 2001 07:42
		Re: changing contrast and brightness on the fly By: slashell on Thu, 21 June 2001 09:55
		Re: changing contrast and brightness on the fly By: John-David T. Smith on Wed, 20 June 2001 13:26
		Re: changing contrast and brightness on the fly By: Liam E. Gumley on Wed, 20 June 2001 07:11
		Re: changing contrast and brightness on the fly By: m.hadfield on Mon, 18 June 2001 18:41

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