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LSB Based Steganography
Steganography is an ancient art of conveying messages in a secret way that only the receiver knows the existence of message. So, a fundamental requirement for a stegano- graphic method is imperceptibility; this means that the embedded messages should not be discernible to the human eye. There are two other requirements, one is to maximize the embedding capacity, and the other is security. The least-significant bit (LSB) insertion method is the most common and easiest method for embedding messages in an image. However, how to decide on the maximal embedding capacity for each pixel is still an open issue. An image steganographic model is proposed that is based on variable-sized LSB insertion to maximise the embedding capacity while maintaining the image fidelity. For each pixel of a gray-scale image, at least 4 bits can be used for messages embedding. First, according to contrast and luminance characteristics, the capacity evaluation is provided to estimate the maximum embedding capacity of each pixel. Then, the minimum-error replacement method is adapted to find a gray-scale as close to the original one as possible.
Index Terms: Matlab, source, code, LSB, least, significant, bit, steganography.
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Figure 1. Bitstream |
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A simple and effective source code for High Capacity Image Steganographic Model. |
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Demo code (protected P-files) available for performance evaluation. Matlab Image Processing Toolbox is required.
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Release
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Date
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Major features
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1.0
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2009.06.20
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We recommend to check the secure connection to PayPal, in order to avoid any fraud. |
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High Capacity Image Steganographic Model. Click here for your donation. In order to obtain the source code you have to pay a little sum of money: 100 EUROS (less than 140 U.S. Dollars).
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Once you have done this, please email us luigi.rosa@tiscali.it
As soon as possible (in a few days) you will receive our new release of High Capacity Image Steganographic Model. Alternatively, you can bestow using our banking coordinates:
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The authors have no relationship or partnership with The Mathworks. All the code provided is written in Matlab language (M-files and/or M-functions), with no dll or other protected parts of code (P-files or executables). The code was developed with Matlab 2006a. Matlab Image Processing Toolbox is required. The code provided has to be considered “as is” and it is without any kind of warranty. The authors deny any kind of warranty concerning the code as well as any kind of responsibility for problems and damages which may be caused by the use of the code itself including all parts of the source code.
Popularity: 1% [?]
GUI Examples #17:Explore popup selection determination
Choosing an item from the popup causes the editbox to display the choice.
function [] = GUI_17() % Demonstrate how to get the chosen string from a popup. % Creates a popup and an editbox. When the user selects a choice from the % popup, this choice will appear in the editbox. % % % Author: Matt Fig % Date: 7/15/2009 S.fh = figure('units','pixels',... 'position',[300 300 300 110],... 'menubar','none',... 'name','GUI_17',... 'numbertitle','off',... 'resize','off'); S.pp = uicontrol('style','pop',... 'units','pixels',... 'position',[20 10 260 40],... 'string',{'one','two','three','four'}); S.ed = uicontrol('style','edit',... 'units','pix',... 'position',[20 60 260 30],... 'fontsize',16,'string','one'); set(S.pp,'callback',{@pp_call,S}); % Set the callback. function [] = pp_call(varargin) % Callback for the popup. S = varargin{3}; % Get the structure. P = get(S.pp,{'string','val'}); % Get the user's choice. set(S.ed,'string',P{1}{P{2}}); % Assign the user's choice to the edit.
Popularity: 2% [?]
CompEcon Toolbox for Matlab
CompEcon is a set of MATLAB functions for solving a variety of problems in economics and finance. The library functions include rootfinding and optimization solvers, a integrated set of routines for function approximation using polynomial, splines and other functional families, a set of numerical integration routines for general functions and for common probability distributions, general solvers for Ordinary Differential Equations (both initial and boundary value problems), routines for solving discrete and continuous time dynamic programming problems, and a general solver for financial derivatives (bonds, futures, options).
The CompEcon Toolbox was developed to accompany:
Applied Computational Economics and Finance, Mario J. Miranda & Paul L. Fackler, MIT Press
MATLAB code for all of the examples in the text is supplied with the CompEcon Toolbox.
The CompEcon Toolbox runs only any MATLAB version 5 or higher.
Popularity: 2% [?]
Delaunay2_5D: a Straightforward Algorithm for Fast Surface Reconstruction
Filed under: Algorithms, Computational Geometry, Graphics
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Contents
Description
Delaunay2_5D is an algorithm for fast surface reconstruction from scattered points cloud. The algorithm is designed to be quick and light. With this tool you’ll be able to reconstruct on your “little” laptop huge points cloud (several millions of points) which are generally considered a Workstation Job.
The project was made possible thanks to the collaboration of Luca Di Angelo and Di Stefano Paolo.
The algorithm uses a mesh growing approach: starting form a seed triangle a front propagation is performed. This technique is generally less accurate than the ones that use Delaunay Triangulation, on the other side they are terribly faster and lighter, so they are preferred for huge models
Perfomances
Usage
Release
We currently have only one Win32 version of Delaunay2_5D.
Release History:
- Delaunay2_5D v1.0 ( 01/02/2010)
Demo version
The demo version differs from the original in the output mode. It has no output parameter so it forces tha user to suppress STL file creation and to visualize the reconstructed surface in output window.
Contributor version
The contributor version returns an STL binary file of the reconstructed surface. It can be obtained with a small donation as encouragement to improve the code itself. The project was realized without any kind of economical help from any academic or commercial organizations.
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Delaunay2_5D: Fast Surface Reconstruction– Contributor version is reserved to donators. The amount of the donation is 30 euro.
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| Once you have done this, please email us: giaccariluigi@msn.com As soon as possible (in a few days) you will receive our new release of Delaunay2_5D. Alternatively, you can bestow using our banking coordinates:
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| Name : | Luigi Giaccari | ||
| IBAN (International Bank Account Number) : | IT 07 E05550 77710 000000483947 | ||
Further informations can be obtained on my skype contact: luigi.giaccari
Models
A few models to test the algorithm:
| Model | Number of points | Call |
| Nicolò da Uzzano (the one in the picture) | 1M | Delaunay2_5D.exe |
| Thai Statue | 5M | Delaunay2_5D.exe i 3 p1 a 20 |
| Foot | 10k | Delaunay2_5D.exe i 2 p1 |
| Armadillo | 170k | Delaunay2_5D.exe |
| Happy Buddha | 500k | Delaunay2_5D.exe i3 p1 f5 a 25 |
| Dragon | 430k | Delaunay2_5D.exe i2 p1 f5 a 30 |
| Rolling Stage | 600k | Delaunay2_5D.exe |
| Pala | 350k | Delaunay2_5D.exe i 3 f 20 p 4 |
| Neptune | 2M | Delaunay2_5D.exe i 3 p1 a 20 |
Release notes
The Software provided has to be considered “as is” and it is without any kind of warranty. The authors deny any kind of warranty concerning the code as well as any kind of responsibility for problems and damages which may be caused by the use of the code itself including all parts of the source code.
Contacts
For any problem, suggestion, question, bug report, whatever….
- giaccariluigi@msn.com
- skype contact: luigi.giaccari
Popularity: 3% [?]
Delaunay2_5D: Performances
Filed under: Algorithms, Computational Geometry, Graphics
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Perfomances
| Model | n° of input points | n° of output triangles | Time [s] | Mem. Usage [MB] | Rate [ktriangle/s] | Defectivness | |||
| nnmv | holes | ||||||||
| nholes | nbe | ||||||||
| Open surfaces | Foot (**) | 10010 | 19972 | 0.31 | 2.39 | 630.1 | 0 | 0 | – |
| Rolling Stage (**) | 596903 | 1193303 | 2.58 | 150.72 | 460.1 | 3 | 15 | 505 | |
| Valve seat (†) | 675049 | 1348338 | 3.08 | 170.55 | 438.2 | 8 | 20 | 1456 | |
| Nicolò da Uzzano (**) | 946760 | 1891992 | 3.81 | 238.96 | 454.2 | 1 | 0 | – | |
| Thai Statue (*) | 4999997 | 9994088 | 20.43 | 1238.62 | 489.0 | ||||
| Closed surfaces | Rocker-arm (**) | 10044 | 20084 | 0.38 | 2.39 | 515.2 | 0 | 0 | – |
| Stanford Bunny (*) | 35947 | 71884 | 0.097 | 9.05 | 735.3 | 0 | 0 | – | |
| Horse (**) | 48485 | 96859 | 0.14 | 12.61 | 673.9 | 2 | 2 | 19 | |
| Armadillo (*) | 172975 | 345934 | 0.520 | 41.79 | 665.7 | 0 | 0 | – | |
| Pulley (**) | 293672 | 587181 | 0.88 | 77.23 | 661.0 | 1 | 2 | 10 | |
| Turbine Blade 2 (†) | 346103 | 791948 | 1.74 | 100.06 | 449.1 | 14 | 3 | 18 | |
| Dragon (***) | 435545 | 805376 | 1.71 | 107.58 | 427.1 | 12 | 28 | 249 | |
| Bimba (**) | 502694 | 1005172 | 1.49 | 126.99 | 676.1 | 16 | 12 | 220 | |
| Happy Buddha (***) | 503897 | 1004540 | 2.09 | 136.95 | 480.4 | 32 | 47 | 462 | |
| Chinese Dragon (**) | 655980 | 1311296 | 1.81 | 165.59 | 723.7 | 47 | 35 | 928 | |
| Turbine Blade (***) | 869555 | 1759357 | 2.73 | 227.74 | 454.8 | 42 | 66 | 1054 | |
| Amphora (**) | 1308237 | 2616596 | 5.99 | 332.56 | 439.2 | 0 | 1 | 10 | |
| Neptune (**) | 2003933 | 4007628 | 8.32 | 488.79 | 481.6 | X | X | X | |
| Asian Dragon (*) | 3609601 | 7218442 | 12.2 | 894.23 | 587.5 | X | X | X | |
| (*) http://www.graphics.stanford.edu/data/3Dscanrep/ (**) http://shapes.aimatshape.net/ |
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The test was performed on My laptop: Asus pro31s. It has 2.4Ghz dual core processor and 2GB of RAM. For some of the models (bigger ones) I was able to mesh them but not to analyze their defectiveness on meshlab or CATIA.
Speed
Tests shows that Delaunay2_5D has a triangles rate production of 400-700 kTriangles/sec. It can mesh a million points cloud in about 4 secs.
Memory Usage
The algorithm is also designed to save memory, the RAM memory usage (in byte) can be estimate before launching the algorithm with the following formula: 240 x N. Where N is the number of points, each points requires about 240 byte of memory. A million points cloud requires only 240MB of RAM.
Quality of Triangles
The quality of triangles is comparable with Delaunay based methods.
Defectiveness
Non manifold vertices and holes
Delaunay2_5D can generated non manifold vertexes and odes not give warranty of a watertight surface reconstruction. If you care about them you have to use a post processing tool.
Non manifold edges
Delaunay2_5D can generate non manifold edges, if you found some, check your clouds has no duplicated points. If it hasn’t you just found a bug, please send me a report.
Duplicated triangles or triangles with different orientation
They can not be generated. if you found some, check your clouds has no duplicated points. If it hasn’t you just found a bug, please send me a report.
Popularity: 2% [?]
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