PixelReplicate.m

%
% PixelReplicate(im, label)
% im can be a logical image - if so it should contain only one connected
%   component
% im can be a label image - it can contain any number of connected components 
%   and label is used to select the component to replicate
% 

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%
% Copyright (c) 2016, Drexel University
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function ptsReplicate_xy = PixelReplicate(im, label)

if nargin>1
    ind = find(im==label);
else
    ind = find(im);
    % NOTE - this is turned off for speed -- but be sure to 
%     [L num]=bwlabel(im);
%     if num>1
%         fprintf(1,'WARNING: PixelReplicate called on >1 connected component\n');
%     end
end    
    
bwd = DepthImageFromPoints(ind,im);

indsReplicate = []; 
idx = find(bwd);

% note - you could use a parfor here for speed with large components
for i=1:length(idx)
    nrep = round(bwd(idx(i)));
    % speed up by using pre-allocated ptsReplicate
    indsReplicate = [indsReplicate;repmat(idx(i),nrep,1)];
end

ptsReplicate_xy = SwapXY_RC(IndToCoord(size(im),indsReplicate));
end

function [bwd, bw] = DepthImageFromPoints(ind,im)

bw = false(size(im));
ind = unique(ind);

bw(ind) = true;
bwd = bwdist(~bw);
end