Looping over function string arguments

The problem is:

%%%%%%%%%%%%%%%%%%%%%%%%%%%This works fine %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%interpolation='bicubic';
interpolation='bilinear';

for scale=1:4
  for image_idx={'01', '02', '03'}
    img_name = strjoin(cellstr(['E:\', image_idx, '.tiff']));
    Iin = imread(img_name);
    ...
    Iout = imresize(Iin, scale, interpolation);
    ...
  end
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%This does not %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for interpolation={'bilinear', 'bicubic'}
  for scale=1:4
    for image_idx={'01', '02', '03'}
      ...
      Iout = imresize(Iin, scale, interpolation);
      ...
    end
  end
end

Second case throws an exception:

Index exceeds matrix dimensions.

Error in imresize>parseMethodArg (line 432)
    kernel_width = method{2};

Error in imresize>parseInputs (line 252)
    [params.kernel, params.kernel_width, params.antialiasing] = ...

Error in imresize (line 141)
params = parseInputs(varargin{:});

Error in test_algorithm (line 25)
    Ic = imresize(Ic, scale, interpolation);

Answer 1

[David Sanchez]

In the second method you are passing a cell array as input argument.

Try this:

interpolation={'bilinear', 'bicubic'};
for k=1:numel(interpolation)
  for scale=1:4
    for image_idx={'01', '02', '03'}
      ...
      Iout = imresize(Iin, scale, interpolation{k});
      ...
    end
  end
end

[Egor]

No errors so far.

Why does this part work as expected so?

    for image_idx={'01', '02', '03'}
      img_name = strjoin(cellstr(['E:\', image_idx, '.tiff']));

It is iterating over "filelist" without additional indexing, isn't it?

[David Sanchez]

They are different command/functions.

strjoin works fine with cell arrays as input arguments.

For any other function, the input arguments has to be a string.

[Egor]

Yeah, just 've got it by myself.

Thanks for the help!