What variable value should I change here?

for num_image = 1 : 1 : 313
    ct1 = dicomread(sprintf('1-%03d.dcm', num_image));
    ct_8 = (ct1)/16;
    c9 = imresize(ct_8, 2);
    ct_fin = uint8(c9); 
    %figure, imshow(ct_fin);
    eval(['imwrite(ct_fin,''' 'test_' num2str([1+(num_image-1)]', '%03i') '.jpg'');']);
end

Answer 1

[KSSV]

for num_image = 1 : 1 : 313
    ct1 = dicomread(sprintf('1-%03d.dcm', num_image));
    ct_8 = (ct1)/16;
    c9 = imresize(ct_8, 2);
    ct_fin = uint8(c9); 
    %figure, imshow(ct_fin);
    imgName = ['test_',num2str(1+(num_image-1)),'.jpg']
    imwrite(ct_fin,imgName);
end