% waveletdemo.m
% demonstration of wavelet decomposition of images
% (C) 2005 by Yu Hen Hu
% created: 11/29/2005

clear all, close all
[tmp,map]=imread('lena.bmp'); % tmp is an indexed image file using 
% color map "map"
x=double(ind2gray(tmp,map)); % convert the image into a grayscale image
clear tmp map;

[LL,LH,HL,HH]=dwt2(x,'haar'); % use Haar wavelet to perform 
% scale LH, HL, HH

figure(1), 
subplot(221),imagesc(LL),colormap('gray'),title('LL')
subplot(222),imagesc(HL),colormap('gray'),title('LH')
subplot(223),imagesc(LH),colormap('gray'),title('HL')
subplot(224),imagesc(HH),colormap('gray'),title('HH')