function smoother_transform = lowpass_image(input_transform,cutoff);

%% function smoother_transform = lowpass_image(input_transform,cutoff);
%%
%% Function to put zeros around the all 4 edges of input variable matrix
%% input_transform. The number of zeros is given in a length 2 vector input
%% variable cutoff.
%%
%% Specific intended use is to perform a crude DFT-domain lowpass filtering
%% operation on the centered (see 'fftshift') 2D DFT of a 2D signal.
%%
%% Note that the inverse transform of the lowpass'ed image may be complex
%% due to lack of attention to preserving the necessary symmetries.
%%
%% D.H. Brooks
%% Rev 1.0, Feb 2004

[xdim,ydim] =size(input_transform);

smoother_transform = input_transform;

smoother_transform(1:cutoff(1),:) = 0;
smoother_transform(:,1:cutoff(2)) = 0;
smoother_transform(xdim - cutoff(1)+1:xdim,:) = 0;
smoother_transform(:,ydim - cutoff(2)+1:ydim) = 0;