Possible to map hue from RGB?

[Henry Barwood]

I have what I hope will not be a stupid question. I want to map RGB hues
independent of intensity. For instance values of 1,1,1 and 25,25,25 are the
same hue, but differ in intensity. Is there a plugin or other function that
can: 1) separate a color field based on hue ratios and show it as a separate
image, 2) allow mapping of a defined range of values, based on the ratios of
RGB pixels?

 

I'm not certain if I've stated this in a way that can be understood. I want
to take Cathodoluminescence images and map color ranges independently of the
color on the image. For instance, I have apatite crystals that show "violet"
zones (REE activation) superimposed on a "yellow" (Mn activated) background.
I want to map the "violet" pixels using a narrow bandwidth of RGB ratios to
bring out subtle variations in the zoning.

 

Is what I'm asking possible? Can ImageJ do this?

 

Thanks for any help.

 

Henry

 

Henry Barwood

Associate Professor of Science, Earth Sciences

Department of Math and Physics

MSCX 312G

Troy University

Troy, Alabama

[hidden email]

 

[Gabriel Landini]

On Monday 25 June 2007 16:45:54 Henry Barwood wrote:
> I have what I hope will not be a stupid question. I want to map RGB hues
> independent of intensity. For instance values of 1,1,1 and 25,25,25 are the
> same hue, but differ in intensity. Is there a plugin or other function that
> can: 1) separate a color field based on hue ratios and show it as a
> separate image, 2) allow mapping of a defined range of values, based on the
> ratios of RGB pixels?

The Threshold_Colour plugin may help:
http://www.dentistry.bham.ac.uk/landinig/software/software.html

Regards,
G.

[Henry Barwood]

Hi,

I downloaded the plugin. Had to upgrade IJ to get it to work. It looks
promising. Thanks.

Henry

Henry Barwood
Associate Professor of Science, Earth Sciences
Department of Math and Physics
MSCX 312G
Troy University
Troy, Alabama
[hidden email]


-----Original Message-----
From: ImageJ Interest Group [mailto:[hidden email]] On Behalf Of
Gabriel Landini
Sent: Monday, June 25, 2007 11:23 AM
To: [hidden email]
Subject: Re: Possible to map hue from RGB?

On Monday 25 June 2007 16:45:54 Henry Barwood wrote:
> I have what I hope will not be a stupid question. I want to map RGB hues
> independent of intensity. For instance values of 1,1,1 and 25,25,25 are
the
> same hue, but differ in intensity. Is there a plugin or other function
that
> can: 1) separate a color field based on hue ratios and show it as a
> separate image, 2) allow mapping of a defined range of values, based on
the
> ratios of RGB pixels?

The Threshold_Colour plugin may help:
http://www.dentistry.bham.ac.uk/landinig/software/software.html

Regards,
G.