gusucode.com > 《MATLAB图像与视频处理实用案例详解》代码 > 《MATLAB图像与视频处理实用案例详解》代码/第 19 章 基于语音识别的信号灯图像模拟控制技术/voicebox/cep2pow.m
function [m,c]=cep2pow(u,v,mode) %CEP2POW convert cepstral means and variances to the power domain % Inputs: % u: vector giving the cepstral means with u(1) the 0'th cepstral coefficient % v: cepstral covariance matrix or else a vector containing the diagonal elements % mode: 'c' pow=exp(irdct(cep)) [default] % 'f' pow=exp(rsfft(cep)/n) [fft length even] % 'fo' pow=exp(rsfft(cep)/n) [fft length odd] % 'i' pow=exp(cep) [ no transformation ] % % Outputs: % m: row vector giving means in the power domain % c: covariance matrix in the power domain % Copyright (C) Mike Brookes 1998 % Version: $Id: cep2pow.m,v 1.4 2007/05/04 07:01:38 dmb Exp $ % % VOICEBOX is a MATLAB toolbox for speech processing. % Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by % the Free Software Foundation; either version 2 of the License, or % (at your option) any later version. % % This program is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the % GNU General Public License for more details. % % You can obtain a copy of the GNU General Public License from % http://www.gnu.org/copyleft/gpl.html or by writing to % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% if nargin<3 mode='c'; end if min(size(v))==1 v=diag(v); end u=u(:)'; % force u to be a row vector if any(mode=='f') n=2*length(u)-2; if any(mode=='o') n=n+1; end p=rsfft(u',n)/n; q=rsfft(rsfft(v,n)',n)/n^2; elseif any(mode=='i') p=u'; q=v'; else p=irdct(u'); q=irdct(irdct(v)'); end m=exp(p+0.5*diag(q))'; c=(m'*m).*(exp(q)-1);