MATLAB: How to change file name and convert the file

Question

Hello,

I have written (borrowed from another user) a very simple code to open a file, resize it, convert to grayscale then save it back into my with a new format and name.

I1=imread('D0159.jpg')

I2 = imresize(I1,[256 256]);

In=rgb2gray(I2)

figure; imshow(In)

imwrite(In,'CottonFiber0016.png')

What I would like to do is automate this. I have seen other people do similar, however I can not make it work. I have a lot of files in a folder and I need them to open, convert and save as new name and autoincrement the number at the end of the file name. You can see I stopped at 16 because I realized there must be a faster way.

Thanks for your help

Answer 1

S = dir('*.jpg');
for k = 1:numel(S)
    im = imread(S(k).name);
    im = imresize(im,[256,256]);
    im = rgb2gray(im);
    fn = sprintf('CottonFiber%04d.png',k);
    imwrite(im,fn)
end

See also:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html