%BAND2OBJ Mapping image bands to objects
%
% B = BAND2OBJ(A,N)
% B = A*BAND2OBJ([],N)
% B = A*BAND2OBJ(N)
%
% INPUT
% A Dataset or datafile with multiband image objects.
% N Number of successive bands to be combined in an object.
% The number of image bands in A should be multiple of N.
% Default N = 1.
%
% OUTPUT
% B Output dataset or datafile.
%
% DESCRIPTION
% If the objects in a dataset or datafile A are multi-band images, e.g. RGB
% images, or the result of IM_PATCH, then the featsize of A is [C,R,L] for
% for L bands of a C x R image. This routine combines sets of N successive
% bands as separate objects. The total number of objects is thereby
% enlarged by a factor L/N. All information of the constituting objects
% like labels, is copied to the newly created objects.
%
% Note: BAND2OBJ cannot be applied to datafiles for which already a
% bandselection (BANDSEL) has been defined.
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, DATAFILES, BANDSEL, IM2OBJ, DATA2IM
% Copyright: R.P.W. Duin, r.p.w.duin@37steps.com
% Faculty EWI, Delft University of Technology
% P.O. Box 5031, 2600 GA Delft, The Netherlands
function b = band2obj(varargin)
argin = shiftargin(varargin,'vector');
argin = setdefaults(argin,[],1);
if mapping_task(argin,'definition')
b = define_mapping(argin,'fixed');
b = setname(b,'Bands to Objects');
else
[a,N] = deal(argin{:});
isvaldfile(a);
%isobjim(a); % datafiles have object images
m = size(a,1);
if isempty(N) % all needed for treating variable numbers of bands
bandnames = getident(a,'bandnames');
if ~isempty(bandnames)
K = zeros(m,1);
for j=1:m, K(j,:) = size(bandnames{j},1); end
if any(K~=K(1))
N = zeros(m,max(K));
for j=1:m, N(j,1:K(j)) = [1:K(j)]; end
else
N = 1;
end
else
N = 1;
end
end
if size(N,1) == m & m > 1 % per object all bands to be selected are given
k = max(N(:));
b = [];
s = sprintf('Checking %i bands: ',k);
prwaitbar(k,s);
for j=1:k
prwaitbar(k,j,[s int2str(j)]);
[I,J] = find(N==j); % Finds all objects for which we have to select band j
if ~isempty(I)
b = [b; bandsel(a(I,:),repmat(j,length(I),1))]; % wrong !!!! bandsel expects something else, solve there!
end
end
prwaitbar(0);
elseif size(N,1) == 1 % N is number of successive objects to be combined
fsize = getfeatsize(a);
k = fsize(3); % We assume that all objects have the same number of bands
if k > 1
if N*round(k/N) ~= k
error('Number of images bands should be multiple of N')
end
size1 = [size(a,1),fsize(1),fsize(2),N,fsize(3)/N];
size2 = [size1(2:4),size1(5)*size(a,1)];
b = im2obj(reshape((shiftdim(reshape(+a,size1),1)),size2));
lablista = getlablist(a);
nlaba = getnlab(a);
nlabb = repmat(nlaba',k/N,1);
b = prdataset(b,lablista(nlabb(:),:));
labim = genlab(ones(1,size(a,1))*(k/N));
curn = curlablist(b);
b = addlabels(b,labim,'org_image');
b = changelablist(b,curn);
b = setident(b,getident(a(str2num(labim),:)));
else
b = a;
end
else
error('Second parameter has wrong size')
end
end
return