2D gaussian filter manual process??

i have image resolution 585x564 pixel and i want to processed with 2d gaussian filter. and i found some code..

function h = Gaussian2D(hsize, sigma)

n1 = hsize; n2 = hsize;

    for i = 1 : n2 
        for j = 1 : n1
        % size is 10;
        % -5<center<5 area is covered.
        c = [j-(n1+1)/2 i-(n2+1)/2]';                
        % A product of both axes is 2D Gaussian filtering
        h(i,j) = Gauss(c(1), sigma)*Gauss(c(2), sigma);        
        end
    end
end

i guest sigma is standard deviation of gaussian distribution. but i dont know what is hsize is?? and the standard deviation,how i can define value for standard deviation??

[nu]

for the Gauss function.

function Gaussian_filtered = Gauss(image_x, sigma) % for single axis % http://en.wikipedia.org/wiki/Gaussian_filter Gaussian_filtered = exp(-image_x^2/(2*sigma^2)) / (sigma*sqrt(2*pi)); end

Answer 1

[Image Analyst]

hsize is the window size. You can have a window of a certain size, and the spread of the Gaussian within that can be anything. I can be really narrow Gaussian so that it completely fits in the window (the filter array), or it can be a really wide Gaussian where the tails get lost because they extend outside the window.