%IM2FEAT Convert Matlab images to dataset feature%%   B = IM2FEAT(IM,A)%% INPUT%   IM    X*Y image, X*Y*K array of K images, or cell-array of images%   A     Input dataset%% OUTPUT%   B     Dataset with IM added%% DESCRIPTION% Add standard Matlab images, as features, to an existing dataset A. If A is% not given, a new dataset is created. Images of type 'uint8' are converted% to 'double' and divided by 256.%% SEE ALSO% DATASETS, IM2OBJ, DATA2IM% Copyright: R.P.W. Duin, duin@ph.tn.tudelft.nl% Faculty of Applied Sciences, Delft University of Technology% P.O. Box 5046, 2600 GA Delft, The Netherlands% $Id: im2feat.m,v 1.4 2003/08/18 15:49:39 dick Exp $function a = im2feat (im,a)	prtrace(mfilename);	if (isa(im,'cell'))		% If IM is a cell array of images, unpack it and recursively call IM2FEAT		% to add each image.		im = im(:);		if (nargin < 2)			a = dataset([]);		end		for i = 1:length(im)			a = [a feval(mfilename,im{i})];		end	else		% If IM is an image or array of images, reshape it and add it in one go.		n = size(im,3); imsize = size(im); imsize = imsize(1:2);		% Convert to double, if necessary		if (isa(im,'uint8'))			prwarning(4,'Image is uint8; converting to double and dividing by 256');			im = double(im)/256;		end		% Reshape images to vectors and store as features in dataset.		im = reshape(im,imsize(1)*imsize(2),n);		if (nargin > 1)			if (~isa(a,'dataset'))				error('Second argument is not a dataset')			end			if (imsize(1)*imsize(2) ~= getobjsize(a))				error('Image size and dataset object size do not match')			end			a = [a im];		else			a = dataset(im);			a = setobjsize(a,imsize);		end	endreturn