Cannot open file using imread

I am trying to load images from a folder but I keep getting an error: "Error using imread (line 347) Cannot open file "./ARL_Stimuli_psych/" for reading. You might not have read permission." Also I am using psychtoolbox and the statistics toolbox

allSTIM=cell(1,length(trialseq_b));
    for i=1:2:length(trialseq_b)
      allSTIM{i} =imread(sprintf('./ARL_Stimuli_psych/%s',stimseq_b{i}));
    end

Answer 1

[Walter Roberson]

Your stimseq_b{i} is empty so you are trying to imread() the directory.

Side note: consider using fullfile() instead of the sprintf() that you are using.

[Britta Hahn]

Thank you, it was empty and I used fullfile() instead of sprintf()