V. Thanikaiselvan ¹, Shounak Shastri ¹, Shaik Ahmad ¹, S Subashanthini ²

Affiliations
1 School of Electronics Engineering, VIT University,Vellore, Tamil Nadu, IN
2 School of Information Technology, VIT University, Vellore, Tamil Nadu, IN

Abstract

Objective: This paper proposes a new data hiding method to improve the security for data hiding. Method: This method first maps the cover image into a 1D pixel sequence and then divides it into non-overlapping blocks containing two successive pixels for embedding. It then calculates the difference between the two pixel values for the blocks. It then compares the difference with a reference table. The reference table is referred in every iteration for the comparison of pixel value differences and the range it falls in. This leads to the calculation of the number of bits which can be embedded in that particular block. Findings: The embedded pixels are then modified and their difference is calculated and compared with the range table. If the difference falls in same range, the embedded pixels are used as modified pixels, and if the difference does not fall in the same range, the pixels are modified such that the difference falls in the appropriate range. Extraction of the data is done in the same way to get the covert data. Application/Improvements: Experimental results show that this method enhances embedding rate while preserving the stego image quality

Keywords

Data Hiding, Embedding Capacity, Imperceptibility, Optimal Pixel Adjustment Process (OPAP), Pixel Value Differencing (PVD), Steganography.

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V. Thanikaiselvan ¹, Tushar Bansal ¹, Prateek Jain ¹, Shounak Shastri ¹

Affiliations
1 School of Electronics Engineering, VIT University, Vellore - 632014, Tamil Nadu, IN

Abstract

Background/Objectives: The advancement of information exchange through internet has made it easy to transfer the exact information faster to the destination. Exchange the information safely to the destination with no alterations, there are many approaches like Cryptography, Steganography and Watermarking. Methods/Statistical Analysis: Steganography is a method of hiding a secret data in other cover medium. Digital Images are popular for cover medium than other because of their frequent use on the internet. In this paper a transform domain steganography with 9/7 Integer Wavelet Transform (IWT) is proposed. A pixel adaptive embedding method using LSB (Least Significant Bit) method is employed to increase the security of the secret data embedded in the a cover medium. Graph Theory is used to select the coefficients randomly for embedding the secret messages. Findings: It is found that the proposed method provides good security and high capacity. This algorithm can be applicable for all kinds of secret communications. Finally Results are compared with 5/3 IWT. Applications/Improvements: This method can be applied for all the secret communication applications especially Defence, Telemedicine, etc. This proposed method developed further in terms of robust against various steganalysis tools.

Keywords

Adaptive Embedding, Data Hiding, IWT, Steganography, Security

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Shounak Shastri ¹, V. Thanikaiselvan ¹

Affiliations
1 School of Electronics Engineering, VIT University, Vellore, Tamil Nadu - 632014, IN

Abstract

Background/Objectives: Pixel Value Ordering (PVO) based embedding is a method for image based Reversible Data Hiding (RDH) to plant secret data in minimum and maximum pixel values of each block of the image. This paper serves as an extension of a recently proposed PVO scheme with higher security and embedding capacity. Methods/Statistical Analysis: In this proposed method the image is first divided into equal sized non-overlapping blocks. The pixels in the individual blocks are ordered according to their values and differences between the maximum and the second largest (or minimum and the second smallest) are computed. Then, histograms of these differences are modified to hide secret information. But original scheme rejects a lot of blocks belonging to textured regions of the image which can be used to embed even more data. Findings: The proposed scheme extends the original PVO method by using these rejected blocks to embed data thus increasing the Embedding Capacity. It is observed that although there is an increase in the overall embedding capacity, the degradation in the visual quality is negligible. It is also found that this increase in the capacity affects the robustness. So a simple randomization technique for the block selection process is also proposed. Applications/Improvements: This method can be applied for all the secret communication applications especially Defence, Telemedicine, etc. This proposed method developed further in terms of robust against various steganalysis tools.

Keywords

Embedding Capacity, Pixel Value Ordering (PVO), Reversible Data Hiding, Steganography, Security

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