dblift.m

此为基于二代提升小波的阈值压缩算法源码

%**************************************************************************
% 函数功能：计算DB小波的提升方案
%**************************************************************************
function LS = DbLift(wname)

Num = wstr2num(wname(3:end));
switch Num
    %== db1 ============================================================%
    case 1          
        LS = {...
            'd',[-1],0; ...
            'p',[1/2],0 ...
            };
        LS(end+1,:) = {sqrt(2),sqrt(2)/2,[]};
   
    %== db2 ============================================================%
    case 2
        LS = {...
                'd',[-sqrt(3)],0; ...
                'p',[sqrt(3)-2 sqrt(3)]/4,1; ...
                'd',[1],-1 ...
            };
        LS(end+1,:) = {(sqrt(3)+1)/sqrt(2),(sqrt(3)-1)/sqrt(2),[]};
        
    %== db3 ============================================================%
    case 3
		LS = {...                                                                 
		'd'                     [ -2.4254972439123361]                      [0]   
		'p'                     [ -0.0793394561587384  0.3523876576801823]  [1]   
		'd'                     [  2.8953474543648969 -0.5614149091879961]  [-1]  
		'p'                     [  0.0197505292372931]                      [2]   
		[  2.3154580432421348]  [  0.4318799914853075]                      []    
		};
    
    %== db4 ============================================================%
    case 4
		LS = {...                                                                                    
		'd'                     [ -0.3222758879971411]                                          [1]  
		'p'                     [ -1.1171236051605939 -0.3001422587485443]                      [0]  
		'd'                     [ -0.0188083527262439  0.1176480867984784]                      [2]  
		'p'                     [  2.1318167127552199  0.6364282711906594]                      [0]  
		'd'                     [ -0.4690834789110281  0.1400392377326117 -0.0247912381571950]  [0]  
		[  0.7341245276832514]  [  1.3621667200737697]                                          []   
		};                                                                                           		
  
    %== db5 ============================================================%
    case 5
		LS = {...                                                                 
		'd'                     [ -0.2651451428113514]                      [1]   
		'p'                     [  0.9940591341382633  0.2477292913288009]  [0]   
		'd'                     [ -0.5341246460905558  0.2132742982207803]  [0]   
		'p'                     [  0.2247352231444452 -0.7168557197126235]  [2]   
		'd'                     [ -0.0775533344610336  0.0121321866213973]  [-2]  
		'p'                     [ -0.0357649246294110]                      [3]   
		[  0.7632513182465389]  [  1.3101844387211246]                      []    
		};                                                                        
    
    case 6
		LS = {...                                                                 
		'd'                     [ -4.4344683000391223]                      [0]   
		'p'                     [ -0.0633131925095066  0.2145934499409130]  [1]   
		'd'                     [  9.9700156175718320 -4.4931131753641633]  [-1]  
		'p'                     [ -0.0236634936395882  0.0574139367993266]  [3]   
		'd'                     [  2.3564970162896977 -0.6787843541162683]  [-3]  
		'p'                     [ -0.0009911655293238  0.0071835631074942]  [5]   
		'd'                     [  0.0941066741175849]                      [-5]  
		[  3.1214647228121661]  [  0.3203624223883869]                      []    
		};                                                                        
        
    case 7
		LS = {...                                                                 
		'p'                     [  5.0934984843051252]                      [0]   
		'd'                     [ -0.1890420920712265  0.0573987259882762]  [0]   
		'p'                     [  5.9592087615113751-12.2854449956285200]  [2]   
		'd'                     [ -0.0604278631256078  0.0291354832685777]  [-2]  
		'p'                     [  1.5604402591648248 -3.9707106658519669]  [4]   
		'd'                     [ -0.0126913773028362  0.0033065734202625]  [-4]  
		'p'                     [  0.0508158836098717 -0.4141984501693177]  [6]   
		'd'                     [ -0.0004062144890730]                      [-6]  
		[  0.2990107076865977]  [  3.3443618381992222]                      []    
		};                                                                        
        
    case 8
		LS = {...                                                                                     
		'd'                     [ -5.7496416141714990]                                          [0]   
		'p'                     [ -0.0522692017330962  0.1688172436569421]                      [1]   
		'd'                     [ 14.5428210043618850 -7.4021068366100549]                      [-1]  
		'p'                     [ -0.0324020739512596  0.0609092564633227]                      [3]   
		'd'                     [  5.8187164907231610 -2.7556987881059287]                      [-3]  
		'p'                     [  0.9452952681157910  0.2420216844324576]                      [5]   
		'd'                     [  0.0001888402536823 -0.0018038158742157]                      [-3]  
		'p'                     [ -0.9526138318957663 -0.2241381624167550]                      [5]   
		'd'                     [  1.0497432943790195 -0.2469917331775993  0.0271973973533717]  [-5]  
		[  3.5493622541356347]  [  0.2817407546481972]                                          []    
		}; 
        
    otherwise
        error('Invalid wavelet number.')
        
end