Gaussian filter in MATLAB

Question

Does the 'gaussian' filter in MATLAB convolve the image with the Gaussian kernel? Also, how do you choose the parameters hsize (size of filter) and sigma? What do you base it on?

Answer 1

You first create the filter with fspecial and then convolve the image with the filter using imfilter (which works on multidimensional images as in the example).

You specify sigma and hsize in fspecial.

Code:

%%# Read an image
I = imread('peppers.png');
%# Create the gaussian filter with hsize = [5 5] and sigma = 2
G = fspecial('gaussian',[5 5],2);
%# Filter it
Ig = imfilter(I,G,'same');
%# Display
imshow(Ig)