i want to write 25 sample image after treatment and save in 10 folders

NSamples=25; NClasses=9;

 for i =1:T
    for s=1:NSamples
        for c=0:NClasses
%traitement---------------------------------------------------------
         img=imread([P I(i).name]);
         R = imresize (img,[100 100]);
         G = rgb2gray(R);
         BW1 = edge(G,'sobel'); 
         classfile =mkdir( sprintf('c%d',c));
         imgfile   = sprintf('%d.png',s);
         fulfile = fullfile(classfile,imgfile);
         dir_file = dir(fulfile)
         imwrite(BW1,dir_file);

        end
    end
end

[Rik]

And what is your question/error?

[zakaria siad]

An unknown error occurred in FULLFILE while constructing the file specification.

Error in Creat_Files_Class(line 21) fulfile = fullfile(classfile,imgfile);

Caused by: Error using horzcat The following error occurred converting from logical to char: Error using char Conversion to char from logical is not possible.

Answer 1

[Rik]

In the code below I fixed some issues with your code. Compare the lines I changed and read the documentation for those functions to better understand their input and output. Especially the output for mkdir and dir.

for c=0:NClasses
    classfoldername=sprintf('c%d',c);
    if ~exist(classfoldername,'dir')
        mkdir(classfoldername);
    end
end
for i =1:T
    for s=1:NSamples
        for c=0:NClasses
%traitement---------------------------------------------------------
            img=imread([P I(i).name]);
            R = imresize (img,[100 100]);
            G = rgb2gray(R);
            BW1 = edge(G,'sobel');
            classfoldername=sprintf('c%d',c);
            imgfile   = sprintf('%d.png',s);
            fulfile = fullfile(classfoldername,imgfile);
            imwrite(BW1,fulfile);
        end
    end
end

[zakaria siad]

Thank you so much

[zakaria siad]

I modified my code but i have problem his create same image into all of folder class

 NSamples=25; NClasses=9;
for c=0:NClasses
    classfoldername=sprintf('N%d',c);
    if ~exist(classfoldername,'dir')
        mkdir(classfoldername);
    end
end
for i =1:250
    for s=0:NSamples
        imgfile   = sprintf('%d.png',s);
        for c=0:NClasses
            classfoldername=sprintf('N%d',c);
%traitement---------------------------------------------------------
            img=imread([P I(i).name]);
            R = imresize (img,[100 100]);
            G = rgb2gray(R);
            G1 = YCrCb(R);
            %BW1 = HOG(R);
            BW1 = edge(G1,'sobel');
%-------------------------------------------------------------------
                fulfile =fullfile(classfoldername,imgfile);
            imwrite(BW1,fulfile);
        end
    end
end