Error message: Colormaps cannot have values outside range (0,1)

Hello,

I'm trying to analyze the intensity of some images (RGB values) but when I run the code I get this error message:

Error using rgb2hsv>parseInputs (line 101)

Valid colormaps cannot have values outside the range [0,1].

Error in rgb2hsv (line 36)

[r, g, b, isColorMap, isEmptyInput, isThreeChannel] = parseInputs(varargin{:});

Error in AnalyzeIntensity071108 (line 64)

HSV(:,:,image_num)=rgb2hsv(RGB(:,:,image_num));

Has someone had a similar problem? If so, how did you fix it?

Thanks!

[Adam]

Make sure your data doesn't have values outside that range. Without seeing any of your code or the image in question it's hard to say anything more. The error message is very clear as to what is wrong. As to why, we need more information to know. Maybe you are trying to pass an Unsigned8 image, although I imagine the error message would be different in that case, maybe you cast it to double without rescaling, maybe any one of a number of things.

[Ana Sofia Lorda]

Hi Adam,

The image I'm trying to analyze is here below. It was previously calibrated.

One of the errors (Error in AnalyzeIntensity071108 (line 64)

HSV(:,:,image_num)=rgb2hsv(RGB(:,:,image_num));) comes from this line in the code:

RGB(:,:,image_num)=[Res1_r;Res1_g;Res1_b]';

HSV(:,:,image_num)=rgb2hsv(RGB(:,:,image_num));

Thank you for your help.

Answer 1

[Walter Roberson]

Your image number is a scalar so RGB(:, :, image_num) is 2d not an rgb image. When you pass 2d to rgb2hsv then you need to pass a colormap of Nx3 values in the range 0 to 1

[Walter Roberson]

RGB(:,:,image_num)=[Res1_r;Res1_g;Res1_b]';

does not create an RGB image. The right hand side is a 2D array that starts out putting color panes as additional rows, and then switches over to columns.

RGB(:,:,:,image_num) = cat(3, Res1_r, Res1_g, Res1_b);
HSV(:,:,:,image_num) = rgb2hsv(RGB(:,:,:,image_num));

[Ana Sofia Lorda]

Hi Walter,

Thanks for your help. This is my first time using MATLAB so I would appreciate if you could bear with me! I changed the line you suggested and still didn't work.

This is the full code:

InputImages=2;
NumPoints=10;
PointWidth=25;
prompt = {'Enter number of input images:','Enter number of points in each image:','Enter averaging window width for each point:'};
dlg_title = 'Input for coral intensity analysis utility';
num_lines= 1;
def     = {num2str(InputImages),num2str(NumPoints),num2str(PointWidth)};
answer  = inputdlg(prompt,dlg_title,num_lines,def);
InputImages=str2double(answer{1});
NumPoints=str2double(answer{2});
PointWidth=str2double(answer{3});
RGB=zeros(NumPoints,3,InputImages);
HSV=zeros(NumPoints,3,InputImages);
for image_num = 1:InputImages
        [filename1, pathname1] = uigetfile( ...
        {'*.jpg;*.jpeg;*.gif;*.bmp','Graphic Files (*.jpg;*.jpeg;*.gif;*.bmp)';
        '*.*',  'All Files (*.*)'}, ...
        ['Pick image file #',num2str(image_num)]);
    if isequal(filename1,0)||isequal(pathname1,0)
        errordlg('File not found','File Error');
    else
        disp(['File ', pathname1, filename1, ' found'])
    end
    im1 = imread([pathname1 filename1]);
    figure('Name',['Image ' int2str(image_num)]);
    imshow(im1);
    title(['Image ' int2str(image_num) ': ' pathname1 filename1]);
    disp(['Please select ',int2str(NumPoints),' points on the coral in image ' int2str(image_num)]);
    % pause
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
    for i=1:NumPoints
        figure(image_num)
        [x,y]=ginput(1);
        hold on
        plot(x,y,'g*')
        half_width=(PointWidth-1)/2;
        X=[(x-half_width) (x-half_width) (x+half_width) (x+half_width)];
        Y=[(y-half_width) (y+half_width) (y+half_width) (y-half_width)];
        ribuax=[X, X(1)];  ribuay=[Y, Y(1)];
        plot(ribuax,ribuay,'b-')
        Res1r (1:PointWidth,1:PointWidth)=im1(floor(y-half_width):floor(y+half_width),floor(x-half_width):floor(x+half_width),1);
        Res1_r(i)=median(median(double(Res1r(:,:))));
        Res1g(1:PointWidth,1:PointWidth)=im1(floor(y-half_width):floor(y+half_width),floor(x-half_width):floor(x+half_width),2);
        Res1_g(i)=median(median(double(Res1g(:,:))));
        Res1b(1:PointWidth,1:PointWidth)=im1(floor(y-half_width):floor(y+half_width),floor(x-half_width):floor(x+half_width),3);
        Res1_b(i)=median(median(double(Res1b(:,:))));
    end
   RGB(:,:,:,image_num) = cat(3, Res1_r, Res1_g, Res1_b ); 
   HSV(:,:,:,image_num) = rgb2hsv(RGB(:,:,:,image_num ));
%     RGB2=[Res2_r;Res2_g;Res2_b]';
%     eval(['RGB',num2str(image_num),'=[Res1_r;Res1_g;Res1_b]']);
%     eval(['HSV',num2str(image_num),'=rgb2hsv(RGB',num2str(i),')']);
end
 
%%%%%%%%%%%%%%%RED%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure('Name','Red intensity profile for selected images');
RED = RGB(:,1,:);
RED = reshape(RED,NumPoints,InputImages);
bar(RED,'group');
legend('Image 1','Image 2');
title('Red  intensity profile analysis for selected images');
xlabel('Point number');
ylabel('Red  intensity coefficient  [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('Red  intensity  full pointwise profile: (row index - number of point, column index - number of picture)');
% disp(RED);
 
RED_mean=mean(RGB(:,1,:));
RED_mean=reshape(RED_mean,1,InputImages);
figure('Name','RGB RED mean value comparison');
title('RGB RED mean value analysis');
bar(RED_mean,'r');
title('RGB RED mean value comparison');
xlabel('Image number');
ylabel('RGB RED mean value [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('RGB RED mean profile: (column index - number of picture)');
% disp(RED_mean);
%%%%%%%%%%%%%%%RED%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
%%%%%%%%%%%%%%GREEN%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure('Name','GREEN  intensity profile for selected images');
GREEN = RGB(:,2,:);
GREEN = reshape(GREEN,NumPoints,InputImages);
bar(GREEN,'group');
legend('Image 1','Image 2');
title('GREEN  intensity profile analysis for selected images');
xlabel('Point number');
ylabel('GREEN  intensity coefficient  [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('GREEN  intensity  full pointwise profile: (row index - number of point, column index - number of picture)');
% disp(GREEN);
 
GREEN_mean=mean(RGB(:,2,:));
GREEN_mean=reshape(GREEN_mean,1,InputImages);
figure('Name','RGB GREEN mean value comparison');
title('RGB GREEN mean value analysis');
bar(1:InputImages,GREEN_mean,'g');
title('RGB GREEN mean value comparison');
xlabel('Image number');
ylabel('RGB GREEN mean value [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('RGB GREEN mean profile: (column index - number of picture)');
% disp(GREEN_mean);
%%%%%%%%%%%%%%GREEN%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
%%%%%%%%%%%%%%%BLUE%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure('Name','BLUE intensity profile for selected images');
BLUE = RGB(:,3,:);
BLUE = reshape(BLUE,NumPoints,InputImages);
bar(BLUE,'group');
legend('Image 1','Image 2');
title('BLUE  intensity profile analysis for selected images');
xlabel('Point number');
ylabel('BLUE  intensity coefficient  [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('BLUE  intensity  full pointwise profile: (row index - number of point, column index - number of picture)');
% disp(BLUE);
 
BLUE_mean=mean(RGB(:,3,:));
BLUE_mean=reshape(BLUE_mean,1,InputImages);
figure('Name','RGB BLUE mean value comparison');
title('RGB BLUE mean value analysis');
bar(1:InputImages,BLUE_mean,'b');
title('RGB BLUE mean value comparison');
xlabel('Image number');
ylabel('RGB BLUE mean value [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('RGB BLUE mean profile: (column index - number of picture)');
% disp(BLUE_mean);
%%%%%%%%%%%%%%%BLUE%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
%%%%%%%%%%%%%%%HSV%%%%%%%%%%%%%%%%%%%%%%%%%%%
% figure('Name','Full HSV brightness profile for selected images');
% HSV_full = HSV(:,3,:);
% HSV_full = reshape(HSV_full,NumPoints,InputImages);
% bar(HSV_full,'group');
% legend('Image 1','Image 2');
% title('Full brightness profile analysis for selected images');
% xlabel('Point number');
% ylabel('Color brightness coefficient (HSV value) [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('HSV full pointwise profile: (row index - number of point, column index - number of picture)');
% disp(HSV_full);
 
% HSV_mean=mean(HSV(:,3,:));
% HSV_mean=reshape(HSV_mean,1,InputImages);
% figure('Name','HSV mean value comparison');
% bar(1:InputImages,HSV_mean);
% title('HSV mean value analysis');
% xlabel('Image number');
% ylabel('HSV mean value [0 - darkest, 255 - brightest]');
% disp('*********************************************************************************************************************');
% disp('HSV mean profile: (column index - number of picture)');
% disp(HSV_mean);
%%%%%%%%%%%%%%%HSV%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
% Final output
% disp('Coral color intensity (Value column - HSV scale):');
% disp('Image 1 Image 2');
% disp(HSV_full);
disp('Coral color intensity (RGB):');
disp('Image 1 [RED, GREEN, BLUE]');
disp([RED(:,1) GREEN(:,1) BLUE(:,1)]);
disp('Image 2 [RED, GREEN, BLUE]');
disp([RED(:,2) GREEN(:,2) BLUE(:,2)]);