## [f1ff16]: comp / comp_idgtreal_fb.m Maximize Restore History

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126``` ```function [f]=comp_idgtreal_fb(coef,g,L,a,M) %COMP_IDGT_FB Filter bank IDGT. % Usage: f=comp_idgt_fb(c,g,L,a,M); % % This is a computational routine. Do not call it directly. % % Input must be in the M x N*W format, so the N and W dimension is % combined. % % See also: idgt % AUTHOR : Peter L. SĂ¸ndergaard. % TESTING: OK % REFERENCE: OK % Calculate the parameters that was not specified. N=L/a; b=L/M; %W=size(coef,2)/N; W = size(coef,3); N=L/a; b=L/M; gl=length(g); glh=floor(gl/2); % gl-half %if ndims(coef)>2 % error('Reshape to M2 x N*W'); %end; % Apply ifft to the coefficients. coef=ifftreal(coef,M)*sqrt(M); %coef=reshape(coef,M,N,W); % The fftshift actually makes some things easier. g=fftshift(g); f=zeros(L,W,assert_classname(coef,g)); % Make multicolumn g by replication. gw=repmat(g,1,W); ff=zeros(gl,1,assert_classname(coef,g)); % Rotate the coefficients, duplicate them until they have same % length as g, and multiply by g. for w=1:W % ----- Handle the first boundary using periodic boundary conditions. --- for n=0:ceil(glh/a)-1 delay=mod(-n*a+glh,M); for ii=0:gl/M-1 for m=0:delay-1 ff(m+ii*M+1)=coef(M-delay+m+1,n+1,w)*g(m+ii*M+1); end; for m=0:M-delay-1 ff(m+ii*M+delay+1)=coef(m+1,n+1,w)*g(m+delay+ii*M+1); end; end; sp=mod(n*a-glh,L); ep=mod(n*a-glh+gl-1,L); % Add the ff vector to f at position sp. for ii=0:L-sp-1 f(sp+ii+1,w)=f(sp+ii+1,w)+ff(1+ii); end; for ii=0:ep f(1+ii,w)=f(1+ii,w)+ff(L-sp+1+ii); end; end; % ----- Handle the middle case. --------------------- for n=ceil(glh/a):floor((L-ceil(gl/2))/a) delay=mod(-n*a+glh,M); for ii=0:gl/M-1 for m=0:delay-1 ff(m+ii*M+1)=coef(M-delay+m+1,n+1,w)*g(m+ii*M+1); end; for m=0:M-delay-1 ff(m+ii*M+delay+1)=coef(m+1,n+1,w)*g(m+delay+ii*M+1); end; end; sp=mod(n*a-glh,L); ep=mod(n*a-glh+gl-1,L); % Add the ff vector to f at position sp. for ii=0:ep-sp f(ii+sp+1,w)=f(ii+sp+1,w)+ff(ii+1); end; end; % ----- Handle the last boundary using periodic boundary conditions. --- % This n is one-indexed, to avoid to many +1 for n=floor((L-ceil(gl/2))/a)+1:N-1 delay=mod(-n*a+glh,M); for ii=0:gl/M-1 for m=0:delay-1 ff(m+ii*M+1)=coef(M-delay+m+1,n+1,w)*g(m+ii*M+1); end; for m=0:M-delay-1 ff(m+ii*M+delay+1)=coef(m+1,n+1,w)*g(m+delay+ii*M+1); end; end; sp=mod(n*a-glh,L); ep=mod(n*a-glh+gl-1,L); % Add the ff vector to f at position sp. for ii=0:L-sp-1 f(sp+ii+1,w)=f(sp+ii+1,w)+ff(1+ii); end; for ii=0:ep f(1+ii,w)=f(1+ii,w)+ff(L-sp+1+ii); end; end; end; % Scale correctly. f=sqrt(M)*f; ```