From f618466c25d43f3bae9e40920273bf77de1e1149 Mon Sep 17 00:00:00 2001
From: leochanj105 <leochanj@live.unc.edu>
Date: Mon, 19 Oct 2020 23:09:30 -0400
Subject: initial sd-vbs

initial sd-vbs

add sd-vbs

sd-vbs
---
 .../src/matlabPyrTools/buildSCFpyrLevs.m           | 73 ++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100755 SD-VBS/benchmarks/texture_synthesis/src/matlabPyrTools/buildSCFpyrLevs.m

(limited to 'SD-VBS/benchmarks/texture_synthesis/src/matlabPyrTools/buildSCFpyrLevs.m')

diff --git a/SD-VBS/benchmarks/texture_synthesis/src/matlabPyrTools/buildSCFpyrLevs.m b/SD-VBS/benchmarks/texture_synthesis/src/matlabPyrTools/buildSCFpyrLevs.m
new file mode 100755
index 0000000..bd75695
--- /dev/null
+++ b/SD-VBS/benchmarks/texture_synthesis/src/matlabPyrTools/buildSCFpyrLevs.m
@@ -0,0 +1,73 @@
+% [PYR, INDICES] = buildSCFpyrLevs(LODFT, LOGRAD, XRCOS, YRCOS, ANGLE, HEIGHT, NBANDS)
+%
+% Recursive function for constructing levels of a steerable pyramid.  This
+% is called by buildSCFpyr, and is not usually called directly.
+
+% Original code: Eero Simoncelli, 5/97.
+% Modified by Javier Portilla to generate complex bands in 9/97.
+
+function [pyr,pind] = buildSCFpyrLevs(lodft,log_rad,Xrcos,Yrcos,angle,ht,nbands);
+
+if (ht <= 0)
+
+  lo0 = ifft2(ifftshift(lodft));
+  pyr = real(lo0(:));
+  pind = size(lo0);
+
+else
+
+  bands = zeros(prod(size(lodft)), nbands);
+  bind = zeros(nbands,2);
+
+%  log_rad = log_rad + 1;
+  Xrcos = Xrcos - log2(2);  % shift origin of lut by 1 octave.
+
+  lutsize = 1024;
+  Xcosn = pi*[-(2*lutsize+1):(lutsize+1)]/lutsize;  % [-2*pi:pi]
+  order = nbands-1;
+  %% divide by sqrt(sum_(n=0)^(N-1)  cos(pi*n/N)^(2(N-1)) )
+  %% Thanks to Patrick Teo for writing this out :)
+  const = (2^(2*order))*(factorial(order)^2)/(nbands*factorial(2*order));
+
+%
+%  Ycosn = sqrt(const) * (cos(Xcosn)).^order;
+%
+  % analityc version: only take one lobe
+  alfa=	mod(pi+Xcosn,2*pi)-pi;
+  Ycosn = 2*sqrt(const) * (cos(Xcosn).^order) .* (abs(alfa)<pi/2);
+
+  himask = pointOp(log_rad, Yrcos, Xrcos(1), Xrcos(2)-Xrcos(1), 0);
+
+  for b = 1:nbands
+    anglemask = pointOp(angle, Ycosn, Xcosn(1)+pi*(b-1)/nbands, Xcosn(2)-Xcosn(1));
+    banddft = ((-i)^(nbands-1)) .* lodft .* anglemask .* himask;
+    band = ifft2(ifftshift(banddft));
+
+%    bands(:,b) = real(band(:));
+    % analytic version: full complex value
+    bands(:,b)=band(:);
+    bind(b,:)  = size(band);
+  end
+
+  dims = size(lodft);
+  ctr = ceil((dims+0.5)/2);
+  lodims = ceil((dims-0.5)/2);
+  loctr = ceil((lodims+0.5)/2);
+  lostart = ctr-loctr+1;
+  loend = lostart+lodims-1;
+
+  log_rad = log_rad(lostart(1):loend(1),lostart(2):loend(2));
+  angle = angle(lostart(1):loend(1),lostart(2):loend(2));
+  lodft = lodft(lostart(1):loend(1),lostart(2):loend(2));
+  YIrcos = abs(sqrt(1.0 - Yrcos.^2));
+  lomask = pointOp(log_rad, YIrcos, Xrcos(1), Xrcos(2)-Xrcos(1), 0);
+
+  lodft = lomask .* lodft;
+
+  [npyr,nind] = buildSCFpyrLevs(lodft, log_rad, Xrcos, Yrcos, angle, ht-1, nbands);
+
+  pyr = [bands(:); npyr];
+  pind = [bind; nind];
+
+end
+
-- 
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