How to use lpfilter for filtering in frequency domain of an image?

I used the following codes f=imread('phalenges.jpg'); [M,N]=size(f); sig=10; F=fft2(f); H=lpfilter('gaussian',[M,N],'sig'); G=H.*F; g=real(ifft2(G)); imshow(g,[])

But following error message was displayed

??? Undefined function or method 'lpfilter' for input arguments of type 'char'.

Answer 1

[serwan Bamerni]

you should download the lpfilter.m file from internet and put it your work directory to be able to use this function