Sabyasachi Pattnaik

Coherent steganography using Segmentation and DCT

The important issue of modern communication is establishing secret communication while using public channel and is achieved by steganography. In this paper, we propose Coherent Steganographic Technique using Segmentation and Discrete Cosine Transform (CSSDCT). The cover image is divided into 8∗8 blocks and DCT is applied on each block. The number of payload MSB bits is embedded into DCT coefficients of the cover image coherently based on the values of DCT coefficients. It is observed that the proposed algorithm has better PSNR, Security and capacity compared to the existing techniques.

Dual Transform Technique for Robust Steganography

Steganography enables to have a secret communication in modern information technology using public channel. In this paper, we propose Dual Transform Technique for Robust Steganography (DTTRS). The cover image is segmented into blocks of 4*4 each and Discrete Wavelet Transform (DWT) is applied on each block. In the resulting DWT coefficients, blocks of vertical band of 2*2 each are considered and Integer Wavelet Transform (IWT) is applied to get blocks of 1*1 each. The IWT is applied on vertical band of DWT of payload to generate coefficients of payload and are embedded into IWT coefficients of cover image using least significant bit replacement method. On applying IIWT and IDWT, stego image is derived. The concept of error detecting and correcting coding technique is employed to ensure more reliable communication. It is observed that the proposed algorithm has excellent PSNR, provides high level security and more robust compared to individual transform techniques.

Iris Recognition Based on DWT and PCA

An Iris is unique compared to all other biometric and is used to authenticate a person. In this paper, we propose iris recognition based on DWT and PCA (IRDP). The iris region is localized using morphological process and a template is formed by using the left and right part of the iris to the pupil by discarding the upper and lower parts of the iris as they are usually occluded by eyelids and eyelashes. The DWT is applied on the histogram of iris template. The features are generated from the approximation band of the DWT using PCA. The classifiers viz., KNN, RF and SVM are used for matching. It is observed that the proposed algorithm has better performance parameters compared to existing algorithm.

Hybrid Domain in LSB Steganography

The maintenance of privacy and secrecy of information in modern communication is accomplished through steganographic technique. Spatial domain techniques are popular ones in image steganography. In this paper, we propose hybrid steganography (HDLS) which is an integration of both spatial and transform domains. The cover image as well as the payload is divided into two cells each. The RGB components of cover image cell I are separated and then transformed individually from spatial to transform domain using DCT/DWT/FFT and embedded in a special manner, the components of cell II retained in spatial domain itself. The proposed algorithm has better PSNR and security as compared to existing techniques.

Mining images using clustering and data compressing techniques

Satellite images of clouds play a significant role in predicting weather conditions. Frequency of image acquisition varies from one image per minute to one image per hour depending on the climatic conditions. These phenomena result in huge collection and creation of image data warehouse. Permanent storage and transmission of images is a challenging task. In this paper, data mining clustering technique along with Vector Quantisation (VQ) is applied to cluster and compress static colour image. Results are shown to demonstrate the findings both subjectively and visually.

Integration of Spatial and Transform Domain in LSB Steganography

In this paper, we propose an integration of spatial and transform domains in LSB steganography (ISTDLS) where both the cover image as well as payload are divided into two cells each and RGB components of cell-1 are separated. The extracted RGB components of cover image cell-1 are individually transformed from spatial to transform domain using FFT/DCT/DWT and embedded differently, the components of cell-2 are retained in spatial domain itself.