jueves, 1 de noviembre de 2012

Steganography (Program 4)


Hi, this is a post to explain how to put mi message in the three images, the method that i used is the LSB (Less Significative Bit).
The method LSB (as your name says) modifies the last (less significative) bit of a string of bits. 

Ok, the library used in my program is called Image, this library allows me work easier with the pixels of the images, for example the function size returns the size(obviously) of the complete image(it helps to make a path of all the image). Image library contains the put.pixel() function to draw a new image whit the parameters that you wish.
In my code you will understand all these things easier and faster.

This is an example how mi program works...

Firstly makes a list with the content of all the binaries values of the message, for example let's to suppose letter 'a' is equal 1001011, and the first pixel of my image (in RGB format: 30,45,10) is (0011110, 0101101, 0001010), so i replace each bit of the string of bits of the letter 'a' in the last bit of the RGB value.

Like this : 

Old RGB value ---> (0011110, 0101101, 0001010)
Letter 'a' (is not the correct binary value of 'a' but is an example!!!):   1001011

New RGB value ---->  (0011111, 0101101, 0001010)

Ok, this is my code: 

It only fail when there are spaces in blank(" ") .
Any doubt you can leave it in comments.

1 comentario:

  1. Falta la parte que pueda recuperar los mensajes. Además sería medio fácil arreglar lo de los espacios. Caes en el grupito de Rodo et al. de 3 pts :/