非局部均值去噪matlab源码

下载直接可用的非局部均值去噪MATLAB源代码 ，非局部均值是利用空间域相似块进行去噪的一种经典算法

function im_ext = bound_extension（imByBxtype）

% im_ext = bound_extension（imBtype）;
%
% Extend an image for avoiding boundary artifacts
%
%   By Bx:    widths of the added stripes.
%   type:   ‘mirror‘        Mirror extension
%           ‘mirror_nr‘:    Mirror without repeating the last pixel
%           ‘circular‘:     fft2-like
%           ‘zeros‘

% Javier Portilla Universidad de Granada Jan 2004

[NyNxNc] = size（im）;

im_ext = zeros（Ny+2*ByNx+2*BxNc）;
im_ext（By+1:Ny+ByBx+1:Nx+Bx:） = im;

if strcmp（type‘mirror‘）

    im_ext（1:By::） = im_ext（2*By:-1:By+1::）;
    im_ext（:1:Bx:） = im_ext（:2*Bx:-1:Bx+1:）;
    im_ext（Ny+1+By:Ny+2*By::） = im_ext（Ny+By:-1:Ny+1::）;
    im_ext（:Nx+1+Bx:Nx+2*Bx:） = im_ext（:Nx+Bx:-1:Nx+1:）;
    im_ext（1:By1:Bx:） = im_ext（2*By:-1:By+12*Bx:-1:Bx+1:）;
    im_ext（Ny+1+By:Ny+2*ByNx+1+Bx:Nx+2*Bx:） = im_ext（Ny+By:-1:Ny+1Nx+Bx:-1:Nx+1:）;
    im_ext（1:ByNx+1+Bx:Nx+2*Bx:） = im_ext（2*By:-1:By+1Nx+Bx:-1:Nx+1:）;
    im_ext（Ny+1+By:Ny+2*By1:Bx:） = im_ext（Ny+By:-1:Ny+12*Bx:-1:Bx+1:）;

elseif strcmp（type‘mirror_nr‘）    
        
    im_ext（1:By::） = im_ext（2*By+1:-1:By+2::）;
    im_ext（:1:Bx:） = im_ext（:2*Bx+1:-1:Bx+2:）;
    im_ext（Ny+1+By:Ny+2*By::） = im_ext（Ny+By-1:-1:Ny::）;
    im_ext（:Nx+1+Bx:Nx+2*Bx:） = im_ext（:Nx+Bx-1:-1:Nx:）;
    im_ext（1:By1:Bx:） = im_ext（2*By+1:-1:By+22*Bx+1:-1:Bx+2:）;
    im_ext（Ny+1+By:Ny+2*ByNx+1+Bx:Nx+2*Bx:） = im_ext（Ny+By-1:-1:NyNx+Bx-1:-1:Nx:）;
    im_ext（1:ByNx+1+Bx:Nx+2*Bx:） = im_ext（2*By+1:-1:By+2Nx+Bx-1:-1:Nx:）;
    im_ext（Ny+1+By:Ny+2*By1:Bx:） = im_ext（Ny+By-1:-1:Ny2*Bx+1:-1:Bx+2:）;
        
elseif strcmp（type‘circular‘）        
        
    im_ext（1:By::） =  im_ext（Ny+1:Ny+By::）;
    im_ext（:1:Bx:） = im_ext（:Nx+1:Nx+Bx:）;
    im_ext（Ny+1+By:Ny+2*By::） = im_ext（By+1:2*By::）;
    im_ext（:Nx+1+Bx:Nx+2*Bx:） = im_ext（:Bx+1:2*Bx:）;
    im_ext（1:By1:Bx:） = im_ext（Ny+1:Ny+ByNx+1:Nx+Bx:）;
    im_ext（Ny+1+By:Ny+2*ByNx+1+Bx:Nx+2*Bx:） = im_ext（By+1:2*ByBx+1:2*Bx:）;
    im_ext（1:ByNx+1+Bx:Nx+2*Bx:） = im_ext（Ny+1:Ny+ByBx+1:2*Bx:）;
    im_ext（Ny+1+By:Ny+2*By1:Bx:） = im_ext（By+1:2*ByNx+1:Nx+Bx:）;
   
end    
        

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     文件        2254  2008-11-18 14:31  bound_extension.m
     文件       16812  2010-06-14 14:53  nlmeans_lnla2008_goossens.m
     文件        3364  2010-06-14 13:53  psdnoise.m
     文件      269256  2005-07-23 12:18  barbara_big.tif
     文件         335  2006-04-07 20:43  GetPSNR.m