source: trunk/src/transform_field/remove_particles.m @ 198

function DataOut=remove_particles(DataIn,Calib)
%-----------------------------------------------
%parameters
threshold=200
nblock_x=30;%size of image subblocks for analysis
nblock_y=30;
%--------------------------------------------------------- 
DataOut=DataIn;%default

if ~isfield(DataIn,'A')
    DataOut.Txt='remove_particels only valid for input images';
    return
end

%BACKGROUND LEVEL
Atype=class(DataIn.A);
A=double(DataIn.A);
Backg=zeros(size(A));
Aflagmin=sparse(imregionalmin(A));%Amin=1 for local image minima
Amin=A.*Aflagmin;%values of A at local minima
% local background: find all the local minima in image subblocks
sumblock= inline('sum(sum(x(:)))');
Backg=blkproc(Amin,[nblock_y nblock_x],sumblock);% take the sum in  blocks
Bmin=blkproc(Aflagmin,[nblock_y nblock_x],sumblock);% find the number of minima in blocks
Backg=Backg./Bmin; % find the average of minima in blocks
B=imresize(Backg,size(A),'bilinear');% interpolate to the initial size image
ImPart=(A-B);
ImPart=ImPart.*(ImPart>threshold);
DataOut.A=A-ImPart;%
DataOut.A=feval(Atype,DataOut.A);