%IM_STAT Fixed mapping computating some image statistics
%
% B = IM_STAT(A,STAT)
% B = A*IM_STAT([],STAT)
% B = A*IM_STAT(STAT)
%
% INPUT
% A Dataset with object images dataset (possibly multi-band)
% STAT String cell array or series of statistics
%
% OUTPUT
% B Dataset with statistics replacing images (possibly multi-band)
%
% DESCRIPTION
% For all images in the dataset A the statistics as defined in the
% cell array STAT are computed. The following statistics are supported:
% (order is arbitrary)
%
% 'mean', 'row_mean', 'col_mean', 'std', 'row_std','col_std',
% 'min', 'row_min', 'col_min, 'max', 'row_max','col_max,
% 'median','row_median','col_median','size','sum'
%
% Default STAT = {'mean','var','min','max','size'}
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% DATASETS, DATAFILES
% 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 = im_stat(varargin)
argin = shiftargin(varargin,{'char','cell'});
argin = setdefaults(argin,[],'def');
if mapping_task(argin,'definition')
b = define_mapping(argin,'fixed');
b = setname(b,'Image statistics');
else
stats = cell(1,numel(argin)-1);
[a,stats{:}] = deal(argin{:});
if iscell(stats{1})
stats = stats{1};
elseif strcmp(stats{1},'def')
stats = {'mean','std','min','max','size'};
end
if isa(a,'prdataset') % allows datafiles too
isobjim(a);
outsize = [size(stats,1)*getfeatsize(a,3)];
b = filtim(a,mfilename,{stats},outsize);
elseif isa(a,'numeric') || isa(a,'logical') || isa(a,'dip_image') % here we have a single image
a = double(a);
n = length(stats);
b = [];
for i=1:n
switch stats{i}
case 'mean'
b = [b mean(a(:))];
case 'std'
b = [b std(a(:))];
case 'min'
b = [b min(a(:))];
case 'max'
b = [b max(a(:))];
case 'median'
b = [b median(a(:))];
case 'row_mean'
b = [b mean(a,2)'];
case 'row_std'
b = [b std(a,0,2)'];
case 'row_min'
b = [b min(a,[],2)'];
case 'row_max'
b = [b max(a,[],2)'];
case 'row_median'
b = [b median(a,2)'];
case 'col_mean'
b = [b mean(a,1)];
case 'col_std'
b = [b std(a,0,1)];
case 'col_min'
b = [b min(a,[],1)];
case 'col_max'
b = [b max(a,[],1)];
case 'col_median'
b = [b median(a,1)];
case 'size'
b = [b size(a)];
case 'sum'
b = [b sum(a(:))];
otherwise
error('Desired statistics not supported')
end
end
end
end
return