A New Method for Hierarchical Image Steganography

8/3/2019 A New Method for Hierarchical Image Steganography

1/5

A new method for

hierarchical image

steganography.

BY

[email protected]

Ph:9573397032

M.V.D [email protected] ph:9440594512

1
mailto:[email protected]:[email protected]:[email protected]:[email protected]


2/5

ABSTRACT:

A good steganographic technique embeds information in to a carrier image with

virtually imperceptible modification of the image. The present paper found a novel fact

that by inserting the hidden message bit using Least Significant Bit (LSB), the grey value

of the image pixel either remains same or increments or decrements by one. The present

paper is focused on this issue and found that such ambiguity of grey level values by LSB

method comes between successive even and odd grey level values only. In the present

paper a new method called non linear hierarchical steganography on 5X5 window pixel

values, is proposed based on the above technique. The novel method inserts hidden

message on 5X5 windows based on their grey level values and coordinate positions. The

present approach allows for high robustness, embedding capacity and enhanced security.A detailed algorithm is furnished along with the results of its application on some sample

images.

Key words: grey level value; hidden message; even and odd; non linear; robustness

INTRODUCTION:

One of the grounds for discussion in the field of information security is the hidden

exchange of information. To this end, various methods such as cryptography,

steganography, coding, etc have been used. To fight against those people like hackers,

intruders and those stealing information usually we use the cryptography method. In

cryptography, the information is encrypted with a key and only the person who has the

key can decrypt and read the information. So without the key, nobody can access the

information. But encrypted data will attract the attention. In recent years, steganography

is widely used for hidden exchange of information. The word steganography is a Greek

word that means writing in hiding. While implementing this method, the main purpose

is to hide data in a cover media so that other persons will not notice that such data is

there. This is a major distinction of this method with the other methods of hidden

exchange of data because, for example, in the method of cryptography, individuals see

the encoded data and notice that such data exists but they cannot comprehend it.

However, in steganography, individuals can notice at all that data exists in the sources[1].

2


3/5

Most steganography jobs have been performed on images [2], video clips

[3], text [4], music and sound [5]. It has also been implemented on such varying systems

as computers and mobile phones [6]. Nowadays, however, information security has

improved considerably with the other mentioned methods. The steganography method, in

addition to application of cover exchange of information, is also used in such other

fields as copyright protection, preventing e-document forging, etc [7].

In this paper we provide a new architecture platform for hierarchical grey

level modification steganography system, which embeds binary data with in the spatial

domain of the grey scale images by modifying the grey level values of the nonlinearly

selected pixels. This paper is organized as follows: In section II methodology is given.

The results and discussions are given in section III and the final section gives

conclusions.II. METHODOLOGY:

The present method of non linear hierarchical steganography is implemented on a

5 x 5 window. The successive even and odd values are treated as same in the 5x 5

window. If two pixel grey level values have the same value then the least coordinated

value by row wise will be treated as highest value. The process is repeated for each 5X5

non overlapped window.

The above process is applied on the following images and good results are obtained

III. RESULTS and DISCUSSIONS:

The proposed method is applied on more than 32 different images of size

NXM where N and M are greater than or equal to 64. However the present paper shows

four of them of size 100X100. The results indicate robustness of the image and difficulty

in breaking the embedded code. Each character length has been made as 12 bits by

appending four bits to each of the character.

Fig 3(a) Fig 3(b)

3


4/5

Fig 4(a) Fig 4(b)

Fig 5(a) Fig 5(b)

Fig 6(a) Fig 6(b)

Fig 3(a), 4(a), 5(a), 6(a): original images

Fig 3(b), 4(b), 5(b), 6(b): stego images with hidden text start attacking

IV. CONCLUSIONS:

The proposed steganographic method is non linear because message characters

are interested based on the value of the grey level and its co-ordinate position. The

present method identified the ambiguity of grey level values, arises between successive

even and odd values after inserting the hidden message using LSB. Future work includes

extending the method based on descending order of pixel grey level values and

appending more number of pixels for each character, which makes the method as more

dynamic. And it will become more difficult to break the text. The present method can

also be applied on any window size. Thus the present method outperforms the existing

LSB methods.

REFERENCES:

4


5/5

[1] J.C. Judge, "Steganography: Past, Present, Future, "SANS white paper, November 30,

2001, "http://www.sans.org/rr/papers/index.php?id=552", lass visited: 10 February 2006.

[2] R. Chandramouli, N. Memon, "Analysis of LSB based image steganography

techniques," Proceedings of the International Conference on Image Processing, vol. 3, 7-

10 Oct. 2001, pp. 1019 - 1022.

[3] G. Dorr and J.L. Dugelay, "A Guide Tour of Video Watermarking," Signal

Processing: Image Communication, vol. 18, issue 4, 2003, pp. 263-282.

[4] A.M. Alattar and O.M. Alattar, "Watermarking electronic text documents containing

justified paragraphs and irregular line spacing," Proceedings of SPIE, Vol. 5306,

Security, Steganography, and Watermarking of Multimedia Contents VI, June 2004,

pp. 685-695.

[5] K. Gopalan, "Audio steganography using bit modification," Proceedings. of the IEEEInternational Conference on Acoustics, Speech, and Signal Processing, (ICASSP '03),

vol. 2, 6-10 April 2003, pp.421-424.

[6] M. Shirali Shahreza, "An Improved Method for Steganography on Mobile Phone,"

WSEASTransactions on Systems, Issue 7, Vol. 4, July 2005, pp. 955-957.

[7] F. Hartung and B. Girod, "Copyright Protection in Video Delivery Networks by

Watermarking of Pre-Compressed Video," Multimedia Applications, Services and

Techniques - ECMAST '97', Springer Lecture Notes in Computer Science, Vol. 1242,

Springer, Heidelberg, 1997, pp. 423-436.

5

Documents

A New Method for Hierarchical Image Steganography