imagecwt.sci

小波分解源代码

function ImageCWT(cwt,scaling,colors,option,oct,scale)
// ImageCWT -- Image of Continuous Wavelet Transform
//  Usage
//    ImageCWT(cwt,scaling,colors)
//  Inputs
//    cwt      matrix produced by CWT
//    scaling  string, 'Overall', 'Individual'
//    colors   string  argument for colormap
//    option   'lin' or 'log' for the type of display
//    oct      Default=2
//    scale    Default=4
//
//  Side Effects
//    Image Display of Continuous Wavelet Transform
//
//  Copyright Aldo I Maalouf

  [lhs,rhs]=argn();
	if rhs < 5,
		oct = 2;
		scale = 4;
	end
	if rhs < 4
       	    option = 'log';
	end
	sz     = size(cwt);
	n      = sz(1);
	nscale = sz(2);
	noctave= floor(log2(n)) -2;
	nvoice = nscale ./ noctave;

  if  string(option)=='log'  
	  ytix   = linspace(1+(oct-floor(log2(scale))),log2(n)-oct,nscale);
	  xtix   = linspace(0,n,n);
	else
	  xtix   = linspace(0,n,n);
	  ytix   = linspace(fix(n/2),0,fix(nscale));  
	end
	
	if string(scaling)=='Individual',  
	    for k=1:nscale,
		    goodstart = min(n/2 .* 2^(-k/nvoice), n/4);
		   	amin = min(cwt(fix(goodstart):fix(n-goodstart),k));
		    amax  = max((cwt(fix(goodstart):fix(n-goodstart),k)));
		    cwt(:,k) = ((cwt(:,k))-amin) ./ (amax-amin) .*256;
		end
	else 
		amin = min(min(cwt));
	  amax = max(max((cwt)));
		cwt = (cwt+amax) ./ (2*amax) .*256;
	end
	
  if string(option)=='lin'  
	  mtlb_image(xtix,ytix, flipud(cwt'));     
	  plot2d([0;1],[0;1],0);//axis('xy');
	else
	  mtlb_image(xtix,ytix, cwt');
          plot2d([0;1],[0;1],0);//axis('ij');
	  xtitle('','','log2(s)');
	  //xlabel('')
	  //ylabel('log2(s)')
	end
	
	
	xset("colormap",eval(colors));
	
endfunction