to search fractal dimension

Question

Frisda Sianipar 2021-3-13

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/771508-to-search-fractal-dimension

评论： Walter Roberson 2021-3-18

This is already the segmentation stage, and I want to find the fractal dimension but it has an error. Can someone help me?

image_folder = 'F:\kuliah\semester6\TA2\mencoba\output';
outfolder = 'F:\kuliah\semester6\TA2\mencoba\hasil';
if ~isdir(outfolder); mkdir(outfolder); end
files = dir(fullfile(image_folder, '*.jpg'));
 %I presume it has the variable map in it
for iFiles = 1:numel(files)
    thisfilename = fullfile(files(iFiles).folder,files(iFiles).name);
    [~, basename, ext] = fileparts(image_folder);
    citra = imread(thisfilename);
    %change to grayscale
    grayimg = rgb2gray(citra);
    figure, fig2=imshow(grayimg);
    %change to green channel
    green_channel = citra(:,:,2);
    figure, fig3=imshow(green_channel);
    %change to CLAHE (Contrast Limited Adaptive Histogram Equalization)
    CLAHE = adapthisteq(green_channel);
    figure, fig4=imshow(CLAHE);
    ER = edge(CLAHE, 'canny');
    EG = edge(CLAHE, 'canny');
    EB = edge(CLAHE, 'canny');
    anyedge = ER | EG | EB;
    figure, fig5=imshow(anyedge)
    size(fig5)
    fig = figure;
    outfile = fullfile(outfolder, sprintf('%s-coba-%03d.jpg', basename, iFiles));
    saveas(fig5, outfile);
    % yang dihitung dimensinya yaitu citra hasil segmentasi
    [n, r] = fboxcount(figure,'slope');
    %Perhitungan dimensi
    df = -diff(log(n))./diff(log(r));
    %Menampilkan hasil dimensi
    disp(['Df= ' num2str(mean(df(4:8)))]);
% % end
end

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Answer 1

Walter Roberson 2021-3-13

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/771508-to-search-fractal-dimension#answer_646785

you are passing in something that isn't an rgb image.

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Frisda Sianipar 2021-3-15

在 MATLAB Online 中打开

this is sir.

function [n,r] = fboxcount(c,varargin)
c=rgb2gray(c);
ukuran=size(c)
error(nargchk(1,2,nargin));
dim = ndims(c)
width = max(size(c))
p = log(width)/log(2)
if p~=round(p) || any(size(c)~=width)
    p = ceil(p)
    width = 2^p
    switch dim
    case 2
    mz = zeros(width, width);
    mz(1:size(c,1), 1:size(c,2)) = c;
    c = mz;
    end
end
n=zeros(1,p+1)
n(p+1) = sum(c(:));
for g=(p-1):-1:0
    siz = 2^(p-g);
    siz2 = round(siz/2);
    for i=1:siz:(width-siz+1);
        for j=1:siz:(width-siz+1);
            c(i,j) = ( c(i,j) || c(i+siz2,j) || c(i,j+siz2) || c(i+siz2,j+siz2) );
        end
    end
n(g+1) = sum(sum(c(1:siz:(width-siz+1),1:siz:(width-siz+1))));
end
n = n(end:-1:1);
r = 2.^(0:p); % box size (1, 2, 4, 8...)
if any(strncmpi(varargin,'slope',1))
    s=-gradient(log(n))./gradient(log(r));
    semilogx(r, s, 's-');
    ylim([0 dim]);
    xlabel('r, box size'); ylabel('- d ln n / d ln r, local dimension');
    title([num2str(dim) 'D box-count']);
elseif nargout==0 || any(strncmpi(varargin,'plot',1))
    loglog(r,n,'s-');
    xlabel('r, box size'); ylabel('n(r), number of boxes');
    title([num2str(dim) 'D box-count']);
end
if nargout==0
clear rn
end

Walter Roberson 2021-3-17

编辑：Walter Roberson 2021-3-17

You are passing the file name to fboxcount.

Now for most purposes, MATLAB is happy to let you process a character vector as if it was number data (for example '1' treated as 49 and 'A' treated as 65), but a character vector is a vector, a 1 by something array, and fboxcount calls rgb2gray.

rgb2gray permits two different kinds of input parameter:

the input can be a 3d array with third dimension being of length 3. That is, an rgb array. But a file name is 1 by something by 1, not 1 by something by 3, so rgb2gray is not willing to treat a file name as an rgb array
the input can be a 2d array, something by 3, representing a color map, such as the jet colormap. The "something" (number of rows) can validly be 1, so rgb2gray is willing to consider treating a file name character vector as if it is a color map with a single row. However, colormap must have exactly 3 columns and your file name has more than 3 characters in it. If your file name happened to have exactly 3 characters including extension then rgb2gray would be willing to process it as a colormap with one row. Except that then after it passed the size check it would fail the check for the colormap being double precision.

So... no filename can pass the size and type requirements of rgb2gray. And therefore fboxcount is not going to work when you pass it a file name.

Walter Roberson 2021-3-17

在 MATLAB Online 中打开

You convinced me that you really really want to do that even though I have mentioned numerous ways it is a bad idea, so here you go:

if ispc()

image_folder = 'F:\kuliah\semester6\TA2\mencoba';

else

image_folder = fullfile(matlabroot, 'toolbox', 'images', 'imdata');

end

files = dir(fullfile(image_folder, '*.jpg'));

filenames = fullfile({files.folder}, {files.name});

filenames = char(filenames).';

filenames(end+1:ceil(size(filenames,1)/3)*3, :) = ' ';

filenames = rescale(double(filenames), 0, 1, 'InputMin', 32, 'InputMax', 127);

names_cmap = reshape(filenames, 3, []).';

[n, r] = fboxcount(names_cmap,'slope');

ukuran = 1×2

722 3

dim = 2

width = 722

p = 9.4959

p = 10

width = 1024

n = 1×11

0 0 0 0 0 0 0 0 0 0 0

This code will do the entire directory at the same time, in a single call.

%the below is copied directly from your posting except that an "end" was
%added
function [n,r] = fboxcount(c,varargin)
c=rgb2gray(c);
ukuran=size(c)
error(nargchk(1,2,nargin));
dim = ndims(c)
width = max(size(c))
p = log(width)/log(2)
if p~=round(p) || any(size(c)~=width)
    p = ceil(p)
    width = 2^p
    switch dim
    case 2
    mz = zeros(width, width);
    mz(1:size(c,1), 1:size(c,2)) = c;
    c = mz;
    end
end
n=zeros(1,p+1)
n(p+1) = sum(c(:));
for g=(p-1):-1:0
    siz = 2^(p-g);
    siz2 = round(siz/2);
    for i=1:siz:(width-siz+1);
        for j=1:siz:(width-siz+1);
            c(i,j) = ( c(i,j) || c(i+siz2,j) || c(i,j+siz2) || c(i+siz2,j+siz2) );
        end
    end
n(g+1) = sum(sum(c(1:siz:(width-siz+1),1:siz:(width-siz+1))));
end
n = n(end:-1:1);
r = 2.^(0:p); % box size (1, 2, 4, 8...)
if any(strncmpi(varargin,'slope',1))
    s=-gradient(log(n))./gradient(log(r));
    semilogx(r, s, 's-');
    ylim([0 dim]);
    xlabel('r, box size'); ylabel('- d ln n / d ln r, local dimension');
    title([num2str(dim) 'D box-count']);
elseif nargout==0 || any(strncmpi(varargin,'plot',1))
    loglog(r,n,'s-');
    xlabel('r, box size'); ylabel('n(r), number of boxes');
    title([num2str(dim) 'D box-count']);
end
if nargout==0
clear rn
end
end

Frisda Sianipar 2021-3-17

So the code above and below is combined, sir?

Walter Roberson 2021-3-18

在 MATLAB Online 中打开

Store the following code in the file named box_the_names.m

image_folder = 'F:\kuliah\semester6\TA2\mencoba';
files = dir(fullfile(image_folder, '*.jpg'));
filenames = fullfile({files.folder}, {files.name});
filenames = char(filenames).';
filenames(end+1:ceil(size(filenames,1)/3)*3, :) = ' ';
filenames = rescale(double(filenames), 0, 1, 'InputMin', 32, 'InputMax', 127);
names_cmap = reshape(filenames, 3, []).';
[n, r] = fboxcount(names_cmap,'slope');

and use your existing fboxcount.

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