Content Based Watermarking Techniques using HSV and Fractal Dimension in Transform Domain

The central idea of the present paper is based on selecting the watermark information from the host image itself. For which, in this work, we select the fractal dimension as the feature of the host image. The proposed method uses three techniques namely DCT, DWT, combined DCT & DWT to embed the watermark by exploiting Fractal Dimension and Human Visual System (HVS), so that a trade-off between imperceptibility and robustness will be maintained. According to the experimentation results, in all the methods, the watermarked images could be recovered effectively. Our method is also useful to detect the tampered location in the watermarked image correctly. INTRODUCTION A digital watermarking is the process that can be used to hide a piece of information into a multimedia content, which is imperceptible to a human observer, but can be easily detected by a computer. The principle advantage is that the watermark is inseparable from the content. Content based Digital Watermarking involves three major phases: (i) Watermark Creation, (ii) Watermark Embedding, (iii) Watermark Extraction. Digital Watermarks may be a pseudo random sequence or a logo of a company or an image. Watermark embedding is done in the watermark carriers such as Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT), etc., of the original data resulting in watermarked data. The watermarked data can be compressed in order to reduce its size, corrupted by noise during its transmission through a noisy channel. It can be subjected to other common image processing operations such as filtering, histogram modification etc. Digital watermark technology has developed extensively during the recent few years and is widely applied to protect the copyright of a digital image. A digital watermark is the information, embedded imperceptibly and robustly in the host data which cannot be removed. By adding a watermark signal to the host data the watermark signal is unobtrusive and secure in the signal mixture. Background: A new public content-based watermarking method for image authentication using ICA and DCT for gray scale images is proposed in (Dr. Latha Parameswaran and Dr. K. Anbumani, 2008). Based upon this paper, this project has been implemented for color images. Watermarks are embedded in the mid -frequency DCT coefficients. DCT is a widely used technique for watermarking (Francisco J. Gonzalez-Serrano, Harold Y. Molina-Bulla, and Juan J. Murillo-Fuentes, May 2001). In Redundant DWT (RDWT) is used i

Advances in progenitor cell therapy using scaffolding constructs for central nervous system injury.

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in the United States. Current clinical therapy is focused on optimization of the acute/subacute intracerebral milieu, minimizing continued cell death, and subsequent intense rehabilitation to ameliorate the prolonged physical, cognitive, and psychosocial deficits that result from TBI. Adult progenitor (stem) cell therapies have shown promise in pre-clinical studies and remain a focus of intense scientific investigation. One of the fundamental challenges to successful translation of the large body of pre-clinical work is the delivery of progenitor cells to the target location/organ. Classically used vehicles such as intravenous and intra arterial infusion have shown low engraftment rates and risk of distal emboli. Novel delivery methods such as nanofiber scaffold implantation could provide the structural and nutritive support required for progenitor cell proliferation, engraftment, and differentiation. The focus of this review is to explore the current state of the art as it relates to current and novel progenitor cell delivery methods