North Eastern Regional Institute of Science and Technology

About: North Eastern Regional Institute of Science and Technology is a education organization based out in Itanagar, India. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 813 authors who have published 1429 publications receiving 16122 citations.

Singular value decomposition and wavelet-based iris biometric watermarking

Abstract: These days, with technological advancement, it is very easy for miscreants to produce illegal multimedia data copies. Various techniques of copyright protection of free data are being developed daily. Digital watermarking is one such technique, where digital embedding of the copyright information/watermark into the data to be protected. The two major ways of doing so are spatial domain and the robust transform domain. In this study, method for watermarking of digital images, with biometric data is presented. The usage of biometric instead of the traditional watermark increases the security of the image data. The biometric used here is iris. After the retinal scan, it is the most unique biometric. In terms of user friendliness in extracting the biometric, it comes after fingerprint and facial scan. The iris biometric template is generated from subject's eye images. The discrete cosine values of templates are extracted through discrete cosine transform and converted to binary code. This binary code is embedded in the singular values of the host image's coefficients generated through wavelet transform. The original image is thus firstly applied with the discrete wavelet transform followed up by the singular value decomposition of the subband coefficients. The algorithm has been tested with popular attacks for analysis of false recognition and rejection of subjects.

Magnesium porphyrins with relevance to chlorophylls

Abstract: A review on the chemistry of magnesium porphyrins, which have significant interest owing to the relevance to chlorophyll molecules, is presented with emphasis on bicarbonate adducts of magnesium porphyrin and chlorophyll. The chemistry of 26 unique magnesium porphyrins is described as review articles on synthetic magnesium porphyrins are limited. Interest is given to the electron transfer reactions of magnesium porphyrins in artificial photosynthetic systems. The magnesium porphyrins are described considering coordination chemistry, structural aspects, electronic and electrochemical properties.