A Study on Invisible Digital Image and Video Watermarking Techniques

Digital watermarking was introduced as a result of rapid advancement of networked multimedia systems. It had been developed to enforce copyright technologies for cover of copyright possession. This technology is first used for still images however recently they need been developed for different multimedia objects like audio, video etc. Watermarking, that belong to the information hiding field, has seen plenty of research interest. There's a lot of work begin conducted in numerous branches in this field. The image watermarking techniques might divide on the idea of domain like spatial domain or transform domain or on the basis of wavelets. The copyright protection, capacity, security, strength etc are a number of the necessary factors that are taken in account whereas the watermarking system is intended. This paper aims to produce a detailed survey of all watermarking techniques specially focuses on image watermarking types and its applications in today’s world

SECURE TRANSMISSION OF BIO-MEDICAL DATA USING STEGANOGRAPHY

To transmit secret data over the internet, the information should be sent in a way attacker finds it difficult to read the secret data. In this paper patient’s secret information is hidden in the bio-medical signal like ECG/EEG/PPG. The transmitted information generally contains (1) biomedical-signals (2) patient data. Main concerns include privacy and authenticity of the data being transmitted. A secret key is used which is known to sender and receiver. This paper introduces a novel steganography technique that guarantees (1) protection of private data utilizing a key and (2) originality of the bio-medical-signals. To maximize embedding, Fast-Walsh-Hadamard Transform is used to convert the signals into a set of coefficients. The proposed technique can be applied on three bio-medical signals like ECG/EEG/PPG unlike any other technique which uses only one bio-medical signal. To achieve least distortion, coefficients of least significant bit is considered. The algorithm has less impact on the bio-medical signal and the signal at the transmitting side can be recovered with less distortion

Hybrid DWT-DCT algorithm for image and video compression applications

Digital image and video in their raw form require an enormous amount of storage capacity. Considering the important role played by digital imaging and video, it is necessary to develop a system that produces high degree of compression while preserving critical image/video information. There are various transformation techniques used for data compression. Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are the most commonly used transformation. DCT has high energy compaction property and requires less computational resources. On the other hand, DWT is multiresolution transformation. In this work, we propose a hybrid DWT-DCT algorithm for image compression and reconstruction taking benefit from the advantages of both algorithms. The algorithm performs the Discrete Cosine Transform (DCT) on the Discrete Wavelet Transform (DWT) coefficients. Simulations have been conducted on several natural, benchmark, medical and endoscopic images. Several QCIF, high definition, and endoscopic videos have also been used to demonstrate the advantage of the proposed scheme. The simulation results show that the proposed hybrid DWT-DCT algorithm performs much better than the standalone JPEG-based DCT, DWT, and WHT algorithms in terms of peak signal to noise ratio (PSNR), as well as visual perception at higher compression ratio. The new scheme reduces “false contouring” and “blocking artifacts” significantly. The rate distortion analysis shows that for a fixed level of distortion, the number of bits required to transmit the hybrid coefficients would be less than those required for other schemes Furthermore, the proposed algorithm is also compared with the some existing hybrid algorithms. The comparison results show that, the proposed hybrid algorithm has better performance and reconstruction quality. The proposed scheme is intended to be used as the image/video compressor engine in imaging and video applications