Use a struct array, one entry per file.
When it comes time to search on (say) brightness, then
all_brightness = [YourStruct.brightness];
bright_match = all_brightness >= min_to_match & all_brightness <= max_to_match;
matching_entries = YourStruct(bright_match);
Now matching_entries is the subset that match on brightness. You can process them further. For example,
fprintf('The %d images that match are:\n', length(matching_entries));
disp({matching_entries.filename});
