Parse filename and data in filecollection in matlab (in the example images)

parsefilecollection.m

function [imgs]=LoadData(DirName)
    imgs=dir(strcat(DirName,'/*.png'));

    for it=1:numel(imgs)
        %getting metadata from the filename itself
        info=regexp(imgs(it).name,'(test|train)_digit(\d*)_(\d*)','tokens');
        info=info{1};
        if(numel(info)~=3)
            error(strcat(imgs(it).name,' is malformed filename-format'));
        end
        imgs(it).istest=strcmp(info(1),'test');
        imgs(it).digit=info(2);
        imgs(it).id=info(3);

        %load the actual data
        imgs(it).name=strcat(DirName,'/',imgs(it).name); %add folder
        imgs(it).data=double(imread(imgs(it).name));

end