I like to use the multiselect function of uigetfile as an input to a for loop:
[Names,Paths]=uigetfile({'*.img*'},'MultiSelect','on'); %or whatever file extension your images have
entirefile=fullfile(Paths,Names);
for i=1:numel(entirefile) %loop will run a number of times equal to the number of files you selected
%load your image using whichever function you prefer, by
%calling e.g. load(entirefile{i}) (note curly brackets)
%a good way to keep your workspace clean while retaining all images loaded is to load them into a structure, e.g.
imgstruc(i).raw=yourrawimage;
imgstruc(i).noised=addsomenoise
%and so on.
end
