%Location of the image.
  Class1 = 'Training/11';
  % load the dataset
  dirList = dir(fullfile(Class1,'*.ppm'));
  %dirList
  files={dirList.name}';

figure,imshow(files)

Error using imageDisplayValidateParams
   Expected input number 1, I, to be one of these types:

   double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64,
   logical

   Instead its type was cell.

    Error in imageDisplayValidateParams (line 12)
    validateattributes(common_args.CData, {'numeric','logical'},...

    Error in imageDisplayParseInputs (line 79)
    common_args = imageDisplayValidateParams(common_args);

     Error in imshow (line 220)
     [common_args,specific_args] = ...

im1 = imread(files{1}); % Read in first image
imshow(im1); % Show the first image
figure;
im2 = imread(files{2}); % Read in second image
imshow(im2); % Show the second image

figure;
for i = 1 : 9
    subplot(3, 3, i);
    im = imread(files{i});
    imshow(im);
end