function [P,filename,pathname,Params]=centers_list(filename,pathname,Params,DPLAY)
% Usage: [P,filename,pathname,Params]=centers_list(filename,pathname,Params,DPLAY)
% Input: Default usage - centers_list([],[],struct([]),'ON')
% filename - Filename of image file
% pathname - Directory containing image file
% Params - Parameters for cleaning up image as in CleanImage.m
% DPLAY - Sets plots 'ON' or 'OFF';
% Output:
% P - array with 4 columns [Label index | Y position | X position | Area ]
% filename, pathname, Params - Same as input, except nonempty values are
% provided when input values are empty.

% Obtain image file
if isempty(filename)||isempty(pathname)==1
    [filename,pathname]=uigetfile('*','Select an image file');
end

% Read imag
rawimg=imread(fullfile(pathname,filename));
rawimg=uint8(sum(rawimg,3)/3); % Convert color image to grayscale.

% Cleanup image and threshold it to generate a binary image
[img,Params]=CleanImage(rawimg,Params);
THOLD=mean(img(:))-std(img(:));% Threshold should preferable depend on image characteristics
BW=img<THOLD;

% Generate labels for distinct structures and measure their center of mass
% and areas
[L,num]=bwlabel(BW,8);
STATS=regionprops(L,'Centroid','Area');
P=[[1:num]' cat(1,STATS.Centroid) [STATS.Area]'];

%DISPLAY RESULTS ONLY
%The following two lines display the primary results of the program. They may
%be commmented out.
if strcmp(DPLAY,'ON')==1
    figure(1);imagesc(img);axis image;colormap gray;title('Cleaned-up image')
    figure(2);imagesc(L);axis image;colormap([1 1 1;jet]);hold on;plot(P(:,2),P(:,3),'k.','Markersize',10);title('Distinct particles identified')
    drawnow;
end