The cause of the problem is that your inner loop repeatedly processes the same string of the cell array Outputs. So you just keep applying regexprep to the same name, each time adding to whatever you did on the last loop iteration.
The simplest solution would be to NOT use the cell array Outputs at all, but to always start again from the raw (input) filename, e.g. something like this (note how the filename N and extension E do not change in the inner loop):
Input_folder =
Output_folder =
S = dir(fullfile(Input_folder,'*.jpg'));
for ii = 1:numel(S)
F = S(ii).name;
X = imread(fullfile(Input_folder,F));
I = im2bw(X);
[~,N,E] = fileparts(F);
V = [3;6;10];
for jj = 1:numel(V)
se = strel('diamond',V(jj)); %imdilate
J = imdilate(I,se);
Y = I - J;
G = sprintf('%s_%d%s',N,V(jj),E);
imwrite(Y,fullfile(Output_folder,G))
end
end
Note that I also made some other improvements to your code, namely:
- replaced fragile string concatenation with the recommended and robust fullfile.
- replaced fragile '.' matching to locate file extension with the recommended and robust fileparts.
- replaced regexprep and num2str with sprintf.
