using imresize in the fourier domain

x = rand(200,200);
y = imresize(x,2);
v1 = fftn(y);
v = fftn(x);
v2 = imresize(v,1/2) ./ 2;

My question is would v1 and v2 be the same matrix ? or am I using the fourier scaling theorem incorrectly ?

Answer 1

[Farhath Fatima]

Hi Raheem,

As per understanding, v1 and v2 would not be same matrix. First the sizes of both the matrices are not same. Size of v1 is 400*400 and size of v2 is 100*100.

v1 is obtained from y, which inturn is scaled to twice of size of x.

v2 is obtained from scaling v to ½ its size, which inturn is obtained from fourier of x.

First Scaling has to be proper to compare any two matrices.