MATLAB: How to present a sequence of random images full screen

Question

I'm trying to present a sequence of images in random order, where each randomly selected image is followed by an image of a fixation cross.

I've managed to write code to do this, however each time an image is presented, it starts in the small window and is then maximised. Is there a way to get it so that each image opens immediately full screen and the window stays constant throughout the sequence (similar to a powerpoint presentation?)

I have never done any coding before and I am a psychologist who usually deals with qualitative data so this is all very new to me and I have no idea what i'm doing! Any help would be much appreciated.

This is what I've got so far:

       H = imread ('fixcross.jpg');
        L = [ 'x','y','z'] ;
        p = L(randi(numel(L)))
        files = dir([p '\*.jpg']) ;       % all jp gimages in folder 
        N = length(files) ;             % total files 
        idx = randperm(N) ;          % random order of numbers till N 
        for i = 1:N                         % loop for each file
            A = files(idx(i)).name % Filename of random image
            imread(A);             
            imshow(A);
            set(gcf,'MenuBar','none')
            set(gca,'DataAspectRatioMode','auto')
            set(gca,'Position',[0 0 1 1])
            set(gcf, 'Position', get(0, 'Screensize'));
            pause(2);
            imshow(H);
            set(gcf,'MenuBar','none')
            set(gca,'DataAspectRatioMode','auto')
            set(gca,'Position',[0 0 1 1])
            set(gcf, 'Position', get(0, 'Screensize'));
            pause(0.5);
        end

Answer 1

Try this:

H = imread ('fixcross.jpg');
L = [ 'x','y','z'] ;
p = L(randi(numel(L)))
files = dir([p '\*.jpg']) ; % All jpg images in folder starting with one of the letters in L
%files = dir('*.jpg') ;      % All jpg images in folder
numberOfFiles = length(files)           % total files
randomIndexes = randperm(numberOfFiles);          % random order of numbers till N
% Make a maximized figure with no tool bar and pulldown menus that are along top of figure.
hFig = figure('Toolbar', 'none', 'Menu', 'none', 'WindowState', 'maximized');
for k = 1 : numberOfFiles                 % loop for each file
	% Display random image for 2 seconds.
	thisFileName = files(randomIndexes(k)).name  % Filename of random image
	rgbImage = imread(thisFileName);
	image(rgbImage);
	axis('image', 'off');
	pause(2);
	
	% Display H image for 0.5 seconds.
	image(H);
	axis('image', 'off');
	pause(0.5);
end
% Close the figure when done
close(hFig);