how can i get matlab coding for wls filter

 Example 
%   -------
%     RGB = imread('peppers.png'); 
%     I = double(rgb2gray(RGB));
%     I = I./max(I(:));
%     res = wlsFilter(I, 0.5);
%     figure, imshow(I), figure, imshow(res)
%     res = wlsFilter(I, 2, 2);
%     figure, imshow(res)

if(~exist('L', 'var')), L = log(IN+eps); end

if(~exist('alpha', 'var')), alpha = 1.2; end

if(~exist('lambda', 'var')), lambda = 1; end

smallNum = 0.0001;

[r,c] = size(IN); k = r*c;

% Compute affinities between adjacent pixels based on gradients of L dy = diff(L, 1, 1); dy = -lambda./(abs(dy).^alpha + smallNum); dy = padarray(dy, [1 0], 'post'); dy = dy(:);

dx = diff(L, 1, 2); dx = -lambda./(abs(dx).^alpha + smallNum); dx = padarray(dx, [0 1], 'post'); dx = dx(:);

% Construct a five-point spatially inhomogeneous Laplacian matrix B(:,1) = dx; B(:,2) = dy; d = [-r,-1]; A = spdiags(B,d,k,k);

e = dx; w = padarray(dx, r, 'pre'); w = w(1:end-r); s = dy; n = padarray(dy, 1, 'pre'); n = n(1:end-1);

D = 1-(e+w+s+n); A = A + A' + spdiags(D, 0, k, k);

% Solve OUT = A\IN(:); OUT = reshape(OUT, r, c);

[Royi Avital]

Do you mean the Weighted Least Squares filter for Image Processing?