ratedist_mu.m

Matlab时频分析工具箱,希望能对大家有所帮助啊

function RateDist_mu(sig,a,M,mu,R)
%RATEDIST_MU  Rate distortion curves for mu-law encoded Gabor coefficients.
%   Usage:  RateDist_mu(sig,a,M,mu,R)
% 
%   Input parameters
%      sig      : Input signal
%      a,M      : Parameters for dgt
%      mu       : mu constant for mu-law encoding
%      R        : List of bitrates to be examined
% 
%   RATEDIST_MU(sig,a,M,mu,R) computes rate distortion curves
%   for mu-law encoded Gabor coefficients

% 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 3 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 should have received a copy of the GNU General Public License
% along with this program.  If not, see <http://www.gnu.org/licenses/>.

% Author: Bruno Torresani

error(nargchk(5,5,nargin));

signorm = norm(sig);

gf=tfr_create('dgt',a,M,'pgauss','candual');
gc = tfr_ar(gf,sig);

SNR = zeros(max(R),1);

for Nbits = R,
  qgc = gc_mu_uquant(gc,Nbits,mu);
  rsig = tfr_sr(gf,qgc);
  err = norm(rsig - sig);
  SNR(Nbits) = 20*log10(signorm/err);
end

plot(R,SNR(R));

tfr_clear(gf);