Wavelet Toolbox

Example 4: Thresholding Wavelet Packets

• load noisbloc
  x = noisbloc;
  t = wpdec(x,3,'sym4');
  plot(t);
  % Change Node Label from Depth_position to Index and
  % click the node (0). You get the following plot.
  
  
  % Global thresholding.
  t1 = t;
  sorh = 'h';
  thr = wthrmngr('wp1ddenoGBL','penalhi',t);
  cfs = read(t,'data');
  cfs = wthresh(cfs,sorh,thr);
  t1  = write(t1,'data',cfs);
  plot(t1)
  
  % Change Node Label from Depth_position to Index and
  % click the node (0). You get the following plot.
  
  
  % Node by node thresholding. 
  t2 = t;
  sorh = 's';
  thr(1) = wthrmngr('wp1ddenoGBL','penalhi',t);
  thr(2) = wthrmngr('wp1ddenoGBL','sqtwologswn',t);
  tn  = leaves(t);
  for k=1:length(tn)
    node = tn(k);
    cfs = read(t,'data',node);
    numthr = rem(node,2)+1;
    cfs = wthresh(cfs,sorh,thr(numthr));
    t2 = write(t2,'data',node,cfs);
  end
  plot(t2)
  
  % Change Node Label from Depth_position to Index and
  % click the node (0). You get the following plot.
  
  
  

Example 3: A Funny One

Detailed Description of Objects in the Toolbox

© 1994-2005 The MathWorks, Inc.