LSB图片信息隐藏隐藏实验.docx

1、LSB图片信息隐藏隐藏实验上海电力学院高级程序设计（C）课程设计报告LSB信息隐藏实验题目： 院系：计算机科学与技术学院 专业年级： 信息安全2012级 学生姓名：涂桂花 学号： 指导教师：魏为民 2015年4月14日上 海 电 力 学 院实 验 报 告课程名称 实验项目 姓名 学号 班级 专业 同组人姓名 指导教师 魏为民 实验日期 一、实验目的1.用MATLAB函数实现LSB信息隐藏和提取。2.了解信息隐藏的作用和实现方法原理。3.学会分析了解隐藏算法。二、实验内容和步骤如操作环境、系统配置、操作步骤、程序源代码等。1.操作环境操作系统 Windows 7 旗舰版 64位 SP1 ( Di

2、rectX 11 )2.系统配置 处理器 AMD E1-2100 APU with Radeon HD Graphics 双核3.操作步骤1) 打开MATLAB软件，新建文件夹名为“ LSB ”。2) 在“Command Window”窗口里输入“guide”，回车。a. 如下图所示建立图形界面。将5个push button控件的“String”属性设置为下图相应显示的名字，Tag属性设置为pbt+String名的格式。将4个axec控件的Tag属性设置为如下图所显示的名字。3) 分别右键点击5个push button控件，View Callbacks-CallBacks.给每个控件添加Cal

3、lback代码。再添加代码之前要为该fig文件命名。我在本次实验命名为LSB3333.fig。各个控件的代码如下：% - Executes on button press in pbtCover.function pbtCover_Callback(hObject, eventdata, handles)% hObject handle to pbtCover (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user

4、data (see GUIDATA)global gCover;gCover,sFile=loadimg();if isempty(gCover) msgbox(Cover image is empty!,Warning,warn,modal); return;endaxes(handles.axCover);imshow(gCover);iH iW iL=size(gCover);sMsg=sFile,num2str(iH),*,num2str(iW),*,num2str(iL),;set(handles.text1,String,sMsg);% - Executes on button p

5、ress in pbtSecret.function pbtSecret_Callback(hObject, eventdata, handles)% hObject handle to pbtSecret (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)global gSecret;gSecret ,sFile=loadimg();if isempty(gSecret)

6、msgbox(Secret image is empty!,Warning,warn,modal); return;endaxes(handles.axSecret);imshow(gSecret);iH iW iL=size(gSecret);sMsg=sFile,num2str(iH),*,num2str(iW),*,num2str(iL),;set(handles.text1,String,sMsg);set(handles.text2,String,Secret Image);% - Executes on button press in pbtEmbed.function pbtEm

7、bed_Callback(hObject, eventdata, handles)% hObject handle to pbtEmbed (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)global gCover gSecret gStego;if isempty(gCover) msgbox(Cover image is empty! , Warning , warn

8、, modal ); return;endif isempty(gSecret) msgbox(gSecret image is empty! , Warning , warn , modal ); return;endHc,Wc,Lc=size(gCover);Hs,Ws,Ls=size(gSecret);if (Hc=Hs) | (Wc=Ws) | (Lc=Ls) disp(Error: Not Match! ); return;end gStego = uint8(bitor(bitand(gCover,254),bitshift(gSecret,-7);imwrite(gStego,

9、emTmp.bmp );axes(handles.axStego);imshow(gStego,); % - Executes on button press in pbtExtract.function pbtExtract_Callback(hObject, eventdata, handles)% hObject handle to pbtExtract (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user

10、data (see GUIDATA)global gStego;global gCover gSecret;if isempty(gCover) msgbox(Cover image is empty! , Warning , warn , modal ); return;endif isempty(gSecret) msgbox(gSecret image is empty! , Warning , warn , modal ); return;endHc,Wc,Lc=size(gCover);Hs,Ws,Ls=size(gSecret);if (Hc=Hs) | (Wc=Ws) | (Lc

11、=Ls) disp(Error: Not Match! ); return;end gStego = uint8(bitor(bitand(gCover,254),bitshift(gSecret,-7);imwrite(gStego, emTmp.bmp );axes(handles.axStego);imshow(gStego,); if isempty(gStego) msgbox(Stego image is empty! , Warning , warn , modal ); return;endimExtract = uint8(bitand(255,bitshift(gStego

12、,7);imwrite(imExtract, exTmp.bmp );axes(handles.axExtract);imshow(imExtract);msgbox(Extracted Image: exTmp.bmp , Finished );% - Executes on button press in pbtExit.function pbtExit_Callback(hObject, eventdata, handles)% hObject handle to pbtExit (see GCBO)% eventdata reserved - to be defined in a fu

13、ture version of MATLAB% handles structure with handles and user data (see GUIDATA)q=questdlg(Are you sure to exit?,figLSB,Yes,No,No);if strcmp(q,No) return;enddelete *.*%delete (handles.figLSB);delete (LSB3333);4) 将测试图片或者图片文件夹放在LSB文件夹下。最后点击保存。4.程序源代码见附件。三、实验结果1.测试图片1隐藏载体图:Leno图片信息2隐藏秘密图：Boy图片信息2.测试结

14、果1隐藏后的图片信息：2从隐藏后的图中提取出来的秘密图片信息：3.截屏4实验小结1. 遇到的问题总结合分析：（1）问题：点击退出按键后选择退出Yes，不能完全退出。解决方法：查看源代码，经过分析，代码没有错，但是没有实现退出该fig图形窗体而是仅仅退出了询问是否退出的box的小窗口。经过改正源代码后，可实现完全退出。更改后的代码如下【即将原来的delete（handles.figLSB）改为delete（LSB3333）】：q=questdlg(Are you sure to exit?,figLSB,Yes,No,No);if strcmp(q,No) return;enddelete *.

15、*%delete (handles.figLSB);delete (LSB3333);（2）问题：老师提供的代码会出现如下图片的一些问题。1没有选择Secret Message图片也能进行信息图片的隐藏和提取2没有添加Cover图片也能进行信息的隐藏和提取3没有添加Cover和Secret图片，不能进行信息隐藏，却能进行信息提取解决方法：分析老师提供的源代码后，进行改进可解决上述出现的问题，即在没有选择Cover图片或者Secret图片的时候，都不能进行信息隐藏和提取。结果截图如下：2. 未解决的问题1问题描述：没有点击Cover控件和Secret控件选择Cover或者Secret图片或者不选

16、择，也能进行隐藏和提取。分析：没有设计代码判断axec控件是否有图片内容。2问题描述：对于不同格式或者不同大小或者灰白和彩色不同的图片不能进行信息图片的隐藏和提取。分析：本实验代码只能对同种格式且大小相同的图片进行信息图片的隐藏和提取，对于不同格式大小相同或者格式相同大小不同的图片不能进行隐藏和提取。3. 实验效果和分析1LSB算法的抗攻击能力本实验算法比较简单，抗攻击能力弱。2随机选择嵌入位（安全性因素的考虑）本实验算法不能随机选择隐藏信息图片的嵌入位，在本程序中设置的为程序默认值，不能提供安全性，可设计随机生成0-7的随机数对信息图形的不同位置随机进行嵌入。再增加隐藏和提取的用户口令则会使

17、安全性更好。3嵌入位均匀分布于载体每次对图像的一个字节的同一个位嵌入，都是同一个位置，这导致分布不均匀。若实现随机嵌入图像的不同字节时不同嵌入位可提高嵌入位的均匀分布于载体。4信息提取的检错/纠错本实验提取出来的图片和原本要隐藏的信息图片不一样。4. 总结：本实验比较简单，在理解了图形信息隐藏的实质和代码的意义后就能很快理解和掌握。不足的是不能将带算法优化已解决遇到的各种问题。将会在以后的学习当中注意知识的积累和灵活运行。附件：源代码：function varargout = LSB3333(varargin)% LSB3333 MATLAB code for LSB3333.fig% LSB

18、3333, by itself, creates a new LSB3333 or raises the existing% singleton*.% H = LSB3333 returns the handle to a new LSB3333 or the handle to% the existing singleton*.% LSB3333(CALLBACK,hObject,eventData,handles,.) calls the local% function named CALLBACK in LSB3333.M with the given input arguments.%

19、 LSB3333(Property,Value,.) creates a new LSB3333 or raises the% existing singleton*. Starting from the left, property value pairs are% applied to the GUI before LSB3333_OpeningFcn gets called. An% unrecognized property name or invalid value makes property application% stop. All inputs are passed to

20、LSB3333_OpeningFcn via varargin.% *See GUI Options on GUIDEs Tools menu. Choose GUI allows only one% instance to run (singleton).% See also: GUIDE, GUIDATA, GUIHANDLES% Edit the above text to modify the response to help LSB3333% Last Modified by GUIDE v2.5 14-Apr-2015 10:08:25% Begin initialization

21、code - DO NOT EDITgui_Singleton = 1;gui_State = struct(gui_Name, mfilename, . gui_Singleton, gui_Singleton, . gui_OpeningFcn, LSB3333_OpeningFcn, . gui_OutputFcn, LSB3333_OutputFcn, . gui_LayoutFcn, , . gui_Callback, );if nargin & ischar(varargin1) gui_State.gui_Callback = str2func(varargin1);endif

22、nargout varargout1:nargout = gui_mainfcn(gui_State, varargin:);else gui_mainfcn(gui_State, varargin:);end% End initialization code - DO NOT EDIT% - Executes just before LSB3333 is made visible.function LSB3333_OpeningFcn(hObject, eventdata, handles, varargin)% This function has no output args, see O

23、utputFcn.% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)% varargin command line arguments to LSB3333 (see VARARGIN)% Choose default command line output for LSB3333handles.output = hObject;% Updat

24、e handles structureguidata(hObject, handles);% UIWAIT makes LSB3333 wait for user response (see UIRESUME)% uiwait(handles.figure1);% - Outputs from this function are returned to the command line.function varargout = LSB3333_OutputFcn(hObject, eventdata, handles) % varargout cell array for returning

25、output args (see VARARGOUT);% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)% Get default command line output from handles structurevarargout1 = handles.output;% - Executes on button press in pbtC

26、over.function pbtCover_Callback(hObject, eventdata, handles)% hObject handle to pbtCover (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)global gCover;gCover,sFile=loadimg();if isempty(gCover) msgbox(Cover image

27、is empty!,Warning,warn,modal); return;endaxes(handles.axCover);imshow(gCover);iH iW iL=size(gCover);sMsg=sFile,num2str(iH),*,num2str(iW),*,num2str(iL),;set(handles.text1,String,sMsg);% - Executes on button press in pbtSecret.function pbtSecret_Callback(hObject, eventdata, handles)% hObject handle to

28、 pbtSecret (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)global gSecret;gSecret ,sFile=loadimg();if isempty(gSecret) msgbox(Secret image is empty!,Warning,warn,modal); return;endaxes(handles.axSecret);imshow(gS

29、ecret);iH iW iL=size(gSecret);sMsg=sFile,num2str(iH),*,num2str(iW),*,num2str(iL),;set(handles.text1,String,sMsg);set(handles.text2,String,Secret Image);% - Executes on button press in pbtEmbed.function pbtEmbed_Callback(hObject, eventdata, handles)% hObject handle to pbtEmbed (see GCBO)% eventdata r

30、eserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)global gCover gSecret gStego;if isempty(gCover) msgbox(Cover image is empty! , Warning , warn , modal ); return;endif isempty(gSecret) msgbox(gSecret image is empty! , Warning , warn , modal ); retur