Resize image using imresize gives an error in octave

I'm trying to resize a **very small image** using Octave 5.2.0 but I'm not
sure why it's giving an error when trying to resize it

The error happens with the line below:

    img_unique_only = imresize(f2, [640, 480]); %reshape output of unique
colors

-

    error: interp2: cubic requires at least 2 points in each dimension
    error: called from
        interp2 at line 244 column 9
        imremap at line 65 column 19
        imresize at line 135 column 8
        test_small_resize_question at line 30 column 17 (the last line
which is the imresize line)

Code Below:

    pkg load image

    f(:,:,1)=[0;0;0;0;127;128;128;128];

    f(:,:,2)=[0;0;127;128;0;0;0;0];

    f(:,:,3)=[127;128;0;0;0;0;127;128];

%%%%%%%%%%%%%%%%-------------------------------------------------------------------------

    [im_r im_c]=size(f);
    size_min=min(im_r,im_c); %get minum size from row and col
   f2=uint8(f); %convert to image format
    img_unique_only = imresize(f2, [640, 480]); %reshape output of unique
colors

Note: I'm also willing to try another way if better