High-capacity and Robust Image Watermarking Algorithm

With the development of internet, digital media can be manipulated, reproduced, and distributed conveniently over networks. However, illegal copy, transmission and distribution of digital media become an important security issue. In this paper, we propose a high-capacity and robustness method based on discrete wavelet transforms(DWT) and optimal discrete cosine transforms(DCT). We present two approaches, they are: DWT-ODCT(high-capacity and robust image watermarking algorithm based on DWT and optimal DCT), and(P-DWT-ODCT) high-capacity and robust image watermarking algorithm based on DWT and optimal DCT by watermark preprocessing. The watermark image is preprocessed by halftone and quad tree techniques, and the position information about the content is extracted as the actual embedded value. The cover image is transformed by DWT and optimal DCT, which provides high imperceptibility and the least image distortion. Watermark bits are not directly inserted into the frequency coefficient, but embedded by modifying the coefficient according to some rules. With this method, regardless of the approach used, our study are higher capacity and robustness than the existing schemes. The watermark extraction produces high image quality after a variety of attacks.

Development of Algorithm for Audio Watermarking Embedding and Decoding using Patchwork Method under Attacks

To protect digital multimedia content from unauthorized reproduction, digital audio watermarking played crucial role. Audio watermarking for the patchwork method has a relatively good level of perception quality.The challengesbetween security, robustness, and imperceptibility is contemporary area of researchand remains relevant issues. This paper introduces discrete cosine transforms (DCT)-based audio watermarking process using the patchwork method for conventional and advanced signal processing attacks. In the first stage of the watermarking audio signal is divided into an equal number of segments and its sub-segments, and then its coefficients are computed. After eliminating high-frequency related coefficients, remaining coefficients are used to form frame pairs of equal length. Watermarks are embedded in a frame using specific criteria and secured data key.The adjustments are made in such a way that the identification ofWatermarked pairs of DCT frames is done in the decoding process by applying the selection criteria used during the embedding process. From watermarked frames, watermark data is extracted by using a secure data key. The proposed audio watermarking algorithm is implemented and tested under conventional and advance signal processing attacks for robustness, imperceptibility, security, and data payload.

Medical Image Fusion Using Transform Based Fusion Techniques

The principal resolution of the image fusion is to merging indication from different images; CT (Computed Tomography) scan and an MRI (Magnetic Resonance Imaging) and to obtain more informative image. In this paper various transform based fusion methods like; discrete wavelet transform (DWT) and two specialisms of discrete cosine transform (DCT); DCT variance and DCT variance with consistency verification (DCT variance with CV) and stationary wavelet transform (SWT) image fusion procedures are instigated and associated in terms of image evidence. Fused outcomes attained from these fusion techniques are evaluated through distinctive evaluation metrics. A fused result accomplished from DCT variance with CV followed by DCT variance out performs DWT and SWT based image fusion methodologies. The potentiality of DCT features creates value-added evidence in the output fused image trailed by fused results proficient from DWT and SWT based image fusion methods. The discrete cosine transforms (DCT) stranded methods of image fusion are auxiliary accurate and concert leaning in real time solicitations by energy forte of DCT originated ideologies of stationary images. In this effort, a glowing systematic practice for fusion of multi-focus images based on DCT and its flavors are obtainable and demonstrated that DCT grounded fused outcomes exceed other fusion methodologies

Implementation of Modified Signed Discrete Cosine Transform

One of the most important properties of Discrete Cosine Transform (DCT) is high power compaction, due to this property DCT is used for coding, image processing, image compression etc. The DCT application can be speed up by Signed Discrete Cosine Transforms (SDCT). The SDCT is the modification approximates of the DCT. In this paper by proposing signum function we proposed a flow diagram of algorithm and its architecture by considering 8 point transforms.