%BANDSEL Selection of bands from object images
%
% B = BANDSEL(A,J)
% B = A*BANDSEL([],J)
% B = A*BANDSEL(J)
%
% INPUT
% A Dataset or datafile with multi-band object images
% J Indices of bands to be selected
%
% OUTPUT
% B Dataset with selected bands (ordered according to J)
%
% 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 [M,N,L] for
% for L bands of an M x N images. This routine makes a selection J out of
% L. The routine BAND2OBJ may be used to organize the bands vertically
% as separate objects. However, BANDSEL nor BAND2OBJ can be applied to
% datafiles for which already a bandselection has been defined by BANDSEL.
%
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, DATAFILES, IM2OBJ, IM_PATCH, BAND2OBJ
% 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 = bandsel(varargin)
argin = shiftargin(varargin,'vector');
argin = setdefaults(argin,[],1);
if mapping_task(argin,'definition')
b = define_mapping(argin,'fixed');
b = setname(b,'Band Selection');
else
[a,J] = deal(argin{:});
if isdatafile(a) % just store administration
if size(J,1) ~= 1
if size(J,1) ~= size(a,1)
error('Matrix with band indices does not match number of objects')
end
else
J = repmat(J,size(a,1),1);
end
%determine number of bands to be selected
if iscell(J)
n = size(J{1},2);
else
n = size(J,2);
end
%store bandselection as a mapping to be executed
%during dataset conversion
v = prmapping(mfilename,'fixed',{[]},[],0,0);
% make the mappings identical, i.e. independent of v.data
% and store the data in the ident field under 'bandsel'.
% This will enable vertical concatenation of datafiles
J0 = getident(a,'bandsel');
J1 = zeros(size(J));
if ~isempty(J0)
% we already have a bandselection set; change it
if size(J,1) == 1
J1 = J0(:,J);
else
for j=1:size(J0,1)
J1(j,:) = J0(j,J(j,:));
end
end
else
J1 = J;
end
%correct bandnames in ident
a = setident(a,J1,'bandsel');
bandnames = getident(a,'bandnames');
if ~isempty(bandnames)
for j=1:size(a,1)
bandnames{j} = bandnames{j}(J(j,:),:);
end
a = setident(a,bandnames,'bandnames');
end
v = setdata(v,[]);
b = addpostproc(a,v);
elseif isdataset(a) % execute
m = size(a,1);
if isempty(J) % J is stored in a.ident.bandsel
J = getident(a,'bandsel');
% we assume that new bandnames are already set,
% simulataneously with bandsel
if isempty(J) % no bandselection defined
b = a;
return
end
else
if size(J,1) == 1
J = repmat(J(:)',m,1);
else
if size(J,1) ~= m
error('Wrong size of band selection array')
end
end
bandnames = getident(a,'bandnames');
if ~isempty(bandnames)
for j=1:m
bandnames{j} = bandnames{j}(J,:);
end
a = setident(a,bandnames,'bandnames');
end
end
isobjim(a);
fsize = getfeatsize(a);
if length(fsize) < 3
error('No image bands defined for dataset')
end
if any(J(:) > fsize(3))
id = getident(a);
id = id(find(J>fsize(3)));
error(['Wrong index for image bands. Object ident: ' int2str(id(1))] )
end
k = prod(fsize(1:2)); % size of a band
L = repmat((J(:,1)-1)*k,1,k)+repmat([1:k],m,1); % indices of band_1 per object
if size(J,2) > 1 % concatenate in case of multiple band selection
for j=2:size(J,2)
LL = repmat((J(:,j)-1)*k,1,k)+repmat([1:k],m,1); % indices of band_j per object
L = [L LL]; % indices for all bands to be selected
end
end
adata = getdata(a); % Let us do the selection on the data
bdata = zeros(m,k*size(J,2));
for i=1:m % can this be done faster?
bdata(i,:) = adata(i,L(i,:));
end
b = setdat(a,bdata); % store the data in a dataset with all information of a
b = setident(b,[],'bandsel'); % bandselection done, avoid second in case of stacked selections
b = setfeatsize(b,[fsize(1:2) size(J,2)]);
else
error('Illegal command')
end
end
return