How can I use an image as a 2 dimentional function?

Hello, I am trying to do Fast Fourier Transform function on an image which should be put on a 2 dimentional function, here's the fft function downloaded from MathWorks ,

function Y=ft2

   size=length(input);
   l=log2(size);
   p=ceil(l); 
   Y=input; 
   N = 2^p;
   N2=N/2; 
   YY = -pi*sqrt(-1)/N2; 
   WW = exp(YY);  
   JJ = 0 : N2-1;  
   W=WW.^JJ;
   for L = 1 : p-1
      u=Y(:,1:N2);
      v=Y(:,N2+1:N);
      t=u+v;
      S=W.*(u-v);
      Y=[t ; S];
      U=W(:,1:2:N2);
      W=[U ;U];
      N=N2;
      N2=N2/2;
   end;
   u=Y(:,1);
   v=Y(:,2);
   Y=[u+v;u-v];
   Y

I want to apply this function on a grayscale image with the command

   schimage = ft2(myimage,2);

But it doesn't work and the error is "Error using ft2 Too many input arguments."

Can anyone help me please?

[KSSV]

There is an inbuilt function fft2. Why don't you use it?

[Nour Sd]

I don't know how, can you please give me instructions?

[Stephen23]

Your define the function ft2 to have zero input arguments:

function Y=ft2

and then try to call it with two input arguments. You should define the function with the correct number of input arguments that you require.

Answer 1

[KSSV]

Read here: https://in.mathworks.com/help/matlab/ref/fft2.html

[Nour Sd]

Actually, I didn't understand how to use it..

[KSSV]

X = imread('peppers.png') ;
X = rgb2gray(X) ;
Y = fft2(X);
imagesc(abs(fftshift(Y)))

[Nour Sd]

Okay, I don't know if it gives a good result in my case but thank you anyway.