source: trunk/src/transform_field/ima_filter.m @ 658

% 'ima_filter': low-pass filtr of an image (builtin filtering parameter)

%------------------------------------------------------------------------
%%%%  Use the general syntax for transform fields with a single input %%%%
% OUTPUT: 
% DataOut:   output field structure 

%INPUT:
% DataIn:  first input field structure
%------------------------------------------------------------------------
function DataOut=ima_filter(DataIn)
np=20 %size of the filtering window
%definition of the cos shape matrix filter
ix=[1/2-np/2:-1/2+np/2];%
del=np/3;
%fct=exp(-(ix/del).^2);
fct2=cos(ix/((np-1)/2)*pi/2);
%Mfiltre=(ones(5,5)/5^2);
Mfiltre=fct2'*fct2;
Mfiltre=Mfiltre/(sum(sum(Mfiltre)));%normalize filter

DataOut=DataIn; %default
Atype=class(DataIn.A)% detect integer 8 or 16 bits
if numel(size(DataIn.A))==3
    DataOut.A=filter2(Mfiltre,sum(DataIn.A,3));%filter the input image, after summation on the color component (for color images)
    DataOut.A=uint16(DataOut.A); %transform to 16 bit images
else
    DataOut.A=filter2(Mfiltre,DataIn.A)
    DataOut.A=feval(Atype,DataOut.A);%transform to the initial image format
end