小波分析源程序：图像降噪与多级分解应用

%WAVELET BASED COMPRESSION  
               %****************************

%removes all variables, globals, functions and
% MEX links(MATLAB loads and runs a different entry point symbol for C or Fortran MEX-files)
clear all;
% CLOSE ALL  closes all the open figure windows.
close all;
%read the image
input_image1=imread('rice.tif');
%display input image
%add noise
input_image=imnoise(input_image1,'speckle',.01);
figure;
imshow(input_image);
%give the number of decomposition level which must be integer and should not exceed 3
n=input('enter the decomposition level');

%*****************************************************************************
[Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('haar');
% computes four filters associated with the orthogonal or biorthogonal
%  wavelet named in the string 'wname'. 
%    The four output filters are:
 %       LO_D, the decomposition low-pass filter
 %       HI_D, the decomposition high-pass filter
  %      LO_R, the reconstruction low-pass filter
   %     HI_R, the reconstruction high-pass filter
   % Available wavelet names 'wname' are:
   % Daubechies: 'db1' or 'haar', 'db2', ... ,'db45'
    %Coiflets  : 'coif1', ... ,  'coif5'