Thread Subject: Label2rgb

Hi,

I have a binary image that I want two colorize. It has
several objects in it. The label2rgb have preset colormaps.

How can I set my own colors for each label? Do I have to
make my own colormap? How do I do this?

"Torvald Helmer":
<SNIP tired of stock-maps...

> How can I set my own colors for each label? Do I have to
> make my own colormap? How do I do this...

colormaps are simply matrices of the form
     ncol x [R,G,B]
where RGBs are values [0,1]
eg,

% the color map
     ncol=128;
% - eg,
     cmap=[
          ones(ncol,1),...
         (1:ncol).'./ncol,...
         (ncol:-1:1).'./ncol
     ];
% - add some black noise
     rix=randperm(ncol);
     cmap(rix(1:10),:)=0;
% show what we have
     colormap(cmap);
     colorbar;
% now, use <cmap> in your call to label2rgb

us

Torvald Helmer wrote:
> Hi,
>
> I have a binary image that I want two colorize. It has
> several objects in it. The label2rgb have preset colormaps.
>
> How can I set my own colors for each label? Do I have to
> make my own colormap? How do I do this?

You can specify your own colormap in the call to label2rgb:

Syntaxes:

RGB = label2rgb(L)
RGB = label2rgb(L, map)
RGB = label2rgb(L, map, zerocolor)
RGB = label2rgb(L, map, zerocolor, order)

Doc:

http://www.mathworks.com/access/helpdesk/help/toolbox/images/label2rgb.html

---
Steve Eddins
http://blogs.mathworks.com/steve/