blur.m

Nearest neighbors is a semi deconvolution algorithm. I m a newbie in matlab but I hope this helps so

function j = blur(filename, sigma)

%      Blur is a function that given an image as input, it will blur 
%      a copy of it using a gaussian function with parameters
%      determined by the user - radius and sigma.
%      
%      BLUR('filename.xxx', radius, sigma);
% 

if sigma < 1, radius = [2 2];
else radius = [2*sigma 2*sigma];
end
fname = imread(filename);
temp = fspecial('gaussian', radius, sigma);
j = imfilter(imresize(fname, 0.35), temp, 'same', 'conv');