Prev: plot annotation - matlab
Next: Can we convert simulink *.mdl file to matlab *.m file
From: Poh Choo on 16 Nov 2009 08:59
i receive an error stated 'Index exceeds matrix dimensions'.

Error in ==> ind2rgb at 27
r = zeros(size(a)); r(:) = cm(a,1);
what is wrong?how to fix it?

My command is:
clc
[X,map] = imread('C:\Documents and Settings\pohchoo\My Documents\wbc.bmp');

RGB = ind2rgb(X,map);

% Convert image to L*a*b* color space
cform2lab = makecform('srgb2lab');
LAB = applycform(RGB, cform2lab);

% Scale values to range from 0 to 1
L = LAB(:,:,1)/100;

% Perform CLAHE
LAB(:,:,1) = adapthisteq(L,'NumTiles',...
[8 8],'ClipLimit',0.005)*100;

% Convert back to RGB color space
cform2srgb = makecform('lab2srgb');
J = applycform(LAB, cform2srgb);

% Display the results
figure, imshow(RGB);
figure, imshow(J);

Hope 2 get your reply soon.
Thank you.
From: Steve Eddins on 16 Nov 2009 09:38
Poh Choo wrote:
> i receive an error stated 'Index exceeds matrix dimensions'.
>
> Error in ==> ind2rgb at 27
> r = zeros(size(a)); r(:) = cm(a,1);
> what is wrong?how to fix it?
>
> My command is:
> clc
> [X,map] = imread('C:\Documents and Settings\pohchoo\My Documents\wbc.bmp');
>
> RGB = ind2rgb(X,map);
>
> % Convert image to L*a*b* color space
> cform2lab = makecform('srgb2lab');
> LAB = applycform(RGB, cform2lab);
>
> % Scale values to range from 0 to 1
> L = LAB(:,:,1)/100;
>
> % Perform CLAHE
> LAB(:,:,1) = adapthisteq(L,'NumTiles',...
> [8 8],'ClipLimit',0.005)*100;
>
> % Convert back to RGB color space
> cform2srgb = makecform('lab2srgb');
> J = applycform(LAB, cform2srgb);
>
> % Display the results
> figure, imshow(RGB);
> figure, imshow(J);
>
> Hope 2 get your reply soon.
> Thank you.

Your subject line says "CLAHE-error" but the error message says the
problem occurred several lines before you call adapthisteq. Hmm.

Anyway, the error message suggests to me that you might have a bad image
file. Specifically, the colormap contained in the file might have too
few colors for the image.

You can check to see whether this is true:

X_max = max(X(:));
num_colors = size(map, 1);
bad_image_file = X_max >= num_colors

---
Steve Eddins
http://blogs.mathworks.com/steve/
 | 
Pages: 1
Prev: plot annotation - matlab
Next: Can we convert simulink *.mdl file to matlab *.m file