How to save images (or variables) with original names in a new directory in MATLAB?

I wrote some code below but I don't know how to proceed from this point:

Images = dir('C:\Users\Mehran\Desktop\Affin dic\Pubfig\dev croped\*.jpg');   
for i=1:length (Images)
    ImgName=strcat('C:\Users\Mehran\Desktop\Affin dic\Pubfig\dev croped\',Images(i).name);
    Img=((imread(ImgName)));
    Img=imresize(Img,[100 100]);
    ???? 
end

Just like reading in images with imread, use imwrite to write image files to disk. Images has all of the files listed in that directory. As such, I suggest you create a new directory and store all of these images resized using Images that you created earlier.

Images = dir('C:\Users\Mehran\Desktop\Affin dic\Pubfig\dev croped\*.jpg');
outDirectory = 'C:\Users\Mehran\Desktop\Affin dic\Pubfig\dev croped\resized\'; %// New - for output directory
%// New - Make directory
mkdir(outDirectory);

for i=1:length (Images)
    ImgName=strcat('C:\Users\Mehran\Desktop\Affin dic\Pubfig\dev croped\',Images(i).name);
    Img=((imread(ImgName)));
    Img=imresize(Img,[100 100]);
    imwrite(Img, strcat(outDirectory, Images(i).name)); %// Change here
end

The above code is modified so that a new output directory is created. Specifically, in your dev croped directory, I've made a subdirectory called resized that will store the resized images, then we cycle through each image, resize the image, then write the image to the output directory using the same name as each original image.

---

Word of advice - Platform independent implementation

If you want to make your code platform independent, it may be a good idea that you use fullfile to help you create the output directory you want as a chain of other directories pieced together:

%// New, specify base directory
baseDirectory = fullfile('C:', 'Users', 'Mehran', 'Desktop', 'Affin dic', 'Pubfig', 'dev croped');

%// Change
Images = dir(fullfile(baseDirectory, '*.jpg'));

%// New - for output directory
outDirectory = fullfile(baseDirectory, 'resized'); 

%// New - Make directory
mkdir(outDirectory);

for i=1:length (Images)
    ImgName=fullfile(baseDirectory, Images(i).name); %// Change
    Img=((imread(ImgName)));
    Img=imresize(Img,[100 100]);
    imwrite(Img, fullfile(outDirectory, Images(i).name)); %// Change here
end

This to me is more readable... but again, that's my opinion.

Another word of advice - JPEG Quality

JPEG compression is lossy and so loading in the image which is already in JPEG, resizing it and then resaving it will give you more quality loss than it is worth. If you're insistent on using JPEG to write the images, set the 'Quality' flag to 100 when using the imwrite function. This will minimize some of the error and trade off for less compression performed at the expense of a larger file size, but given how cheap storage is today, I think you won't mind:

%// New, specify base directory
baseDirectory = fullfile('C:', 'Users', 'Mehran', 'Desktop', 'Affin dic', 'Pubfig', 'dev croped');

%// Change
Images = dir(fullfile(baseDirectory, '*.jpg'));

%// New - for output directory
outDirectory = fullfile(baseDirectory, 'resized'); 

%// New - Make directory
mkdir(outDirectory);

for i=1:length (Images)
    ImgName=fullfile(baseDirectory, Images(i).name); %// Change
    Img=((imread(ImgName)));
    Img=imresize(Img,[100 100]);
    imwrite(Img, fullfile(outDirectory, Images(i).name), 'Quality', 100); %// Change here
end