Image Enhancement using DWT and IDWT

Question

uday chandu 2012-5-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38108-image-enhancement-using-dwt-and-idwt

回答： ramin ranjbar 2017-2-15

在 MATLAB Online 中打开

AM not getting the correct output after applying IDWT2 function.. can any one look at the code and help me out

code: % input is a gray image y=imread('c:\working\lena.jpg');

%x=rgb2gray(y); [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('haar'); [LL,LH,HL,HH]=dwt2(y,Lo_D,Hi_D);

figure(1),imshow(uint8(LL));title(' LL Image'); figure(2),imshow(y);title('INput Image');

dec=[... LL,LH HL,HH ... ]; LLI = imresize(LL,2,'bicubic'); LHI = imresize(LH,2,'bicubic'); HLI = imresize(HL,2,'bicubic'); HHI = imresize(HH,2,'bicubic'); image=double(y);

    figure(3),imagesc(image); colormap gray;title('doubled input image');
    figure(4),imagesc(LLI); colormap gray;title('iterpolated LL Image');
    figure(5),imagesc(LHI); colormap gray;title('iterpolated LH Image');
    figure(6),imagesc(HLI); colormap gray;title('iterpolated HL Image');
    figure(7),imagesc(HHI); colormap gray;title('iterpolated HH Image');
    Diff_Img=imsubtract(image,LLI);
    figure(8),imagesc(Diff_Img);colormap gray;title('Difference Image');
     [m,n]=size(Diff_Img);
   for i=1:m
       for j=1:n
           ELH(i,j)=(Diff_Img(i,j)+LHI(i,j))/2;
       end
   end
   figure(9),imagesc(ELH);colormap gray;title('Added LH Image');
    for i=1:m
       for j=1:n
           EHL(i,j)=(Diff_Img(i,j)+HLI(i,j))/2;
       end
    end
      figure(10),imagesc(EHL);colormap gray;title('Added HL Image');
    for i=1:m
       for j=1:n
           EHH(i,j)=(Diff_Img(i,j)+HHI(i,j))/2;
       end
   end 
     figure(11),imagesc(EHH);colormap gray;title('Added HH Image');
     %scale the image by factor of two
     scale=2;
    LLI2 = imresize(image,scale/2,'bicubic');
     figure(12),imagesc(LLI2);colormap gray;title('Resized for IDWT input image');
    LHI2 = imresize(ELH,scale/2,'bicubic');
    figure(13),imagesc(LHI2);colormap gray;title('Resized LH Image');
    HLI2 = imresize(EHL,scale/2,'bicubic');
    figure(14),imagesc(HLI2);colormap gray;title('Resized HL Image');
    HHI2 = imresize(EHH,scale/2,'bicubic');
    figure(15),imagesc(HHI2);colormap gray;title('Resized HH Image');
  %  image=im2double(image);
    out=idwt2(LLI2,LHI2,HLI2,HHI2,'haar');
    figure(16),imagesc(out); colormap gray;title('output enhanced image');
    %imshow(unit8(out));

7 个评论
显示 5更早的评论隐藏 5更早的评论

Sumathi K 2013-1-29

How is it posssible to subtarct a time domain Input Image with interpolated Subband which is in frequency domain?

kelvin sako 2014-11-26

can i have the codes of interpolation of wavelet domain please..

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

ramin ranjbar 2017-2-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38108-image-enhancement-using-dwt-and-idwt#answer_254938

在 MATLAB Online 中打开

you can use this code instead of former

clc; clear all; close all;

y=imread('7.jpg'); y=rgb2gray(y);

[m,n]=size(y); [Lo_D,Hi_D,Lo_R,Hi_R] = wfilters('haar'); [LL,LH,HL,HH]=dwt2(y,Lo_D,Hi_D); [m1,n1]=size(LL); imshow(y);title('INput Image'); figure; subplot(3,3,2);imshow(uint8(LL));title(' LL Image'); dec=[LL,LH HL,HH]; err=uint8(idwt2(LL,LH,HL,HH,'haar',[m,n]));

LLI = imresize(LL,2,'bicubic'); LHI = imresize(LH,2,'bicubic'); HLI = imresize(HL,2,'bicubic'); HHI = imresize(HH,2,'bicubic'); image=double(y); err2=uint8(idwt2(image,LHI,HLI,HHI,'haar',[2*m,2*n]));

subplot(3,3,3);imshow(uint8(image));title('doubled input image'); subplot(3,3,4);imshow(uint8(LLI));title('iterpolated LL Image'); subplot(3,3,5);imshow(uint8(LHI));title('iterpolated LH Image'); subplot(3,3,6);imshow(uint8(HLI));title('iterpolated HL Image'); subplot(3,3,7);imshow(uint8(HHI));title('iterpolated HH Image'); %Diff_Img=(imsubtract(image,LLI)); Diff_Img=image; subplot(3,3,8);imshow(uint8(Diff_Img));title('Difference Image'); figure;imshow(err);title('reconstructed Image'); figure;imshow(err2);title('reconstructed Image'); [m,n]=size(Diff_Img); b=32; for i=1:m for j=1:n ELH(i,j)=((Diff_Img(i,j)+LHI(i,j))/b);% end end

% figure(9),imshow(ELH);title('Added LH Image');
  for i=1:m
     for j=1:n
         EHL(i,j)=((Diff_Img(i,j)+HLI(i,j))/b);%
     end
  end
%    figure(10),imshow(EHL);title('Added HL Image');
  for i=1:m
     for j=1:n
         EHH(i,j)=((Diff_Img(i,j)+HHI(i,j))/b);%
     end
 end 
  % figure(11),imshow(EHH);title('Added HH Image');
   %scale the image by factor of two
   scale=2;
  LLI2 = imresize(image,scale/2,'bicubic');
%  figure(12),imshow(LLI2);colormap gray;title('Resized for IDWT input image');
  LHI2 = imresize(ELH,scale/2,'bicubic');
%  figure(13),imshow(LHI2);colormap gray;title('Resized LH Image');
  HLI2 = imresize(EHL,scale/2,'bicubic');
 % figure(14),imshow(HLI2);colormap gray;title('Resized HL Image');
  HHI2 = imresize(EHH,scale/2,'bicubic');
 % figure(15),imshow(HHI2);colormap gray;title('Resized HH Image');
%  image=im2double(image);
% out=uint8(idwt2(LLI2,LHI2,HLI2,HHI2,'haar',[m,n]));
   out=uint8(idwt2(image,LHI2,HLI2,HHI2,'haar',[2*m,2*n]));
   out=imresize(out,.5);
  figure(16),imshow(out);title('output enhanced image');