Robust digital watermarking for compressed 3D models based on polygonal representation

Multimedia has recently played an increasingly important role in various domains, including Web applications, movies, video game and medical visualization. The rapid growth of digital media data over the Internet, on the other hand, makes it easy for anyone to access, copy, edit and distribute digital contents such as electronic documents, images, sounds and videos. Motivated by this, much research work has been dedicated to develop methods for digital data copyright protection, tracing the ownership, and preventing illegal duplication or tampering. This paper introduces a methodology of robust digital watermarking based on a well-known spherical wavelet transformation, applied to 3D compressed model based on polygonal representation using a neural network. It will be demonstrated in this work that applying a watermarking algorithm on a compressed domain of a 3D object is more effective, efficient, and robust than when applied on a normal domain

Crystal structure of 4-azidomethyl-6-tert-butyl-2H-chromen-2-one

MM would like to thank UGC, New Delhi, Government of India, for the award of a project under the head F. No. 41–920/2012(SR) (dated: 25-07-2012). In addition, SD is thankful to the Council of Scientific and Industrial Research, New Delhi, India, for financial assistance [grant No. 02 (0172)/13/EMRII].Peer reviewedPublisher PD

Geometry Compression for 3D Polygonal Models using a Neural Network

Three dimensional models are commonly used in computer graphics and 3D modeling characters in animation movies and games. 3D objects are more complex to handle than other multimedia data due to the fact that various representations exist for the same object, yielding a number of difficulties, among of which are the distinct sources of 3D data. Research work in the field of three dimensional environments is represented by a broad spectrum of applications. In this paper we restrict ourselves only on how to do compression using a neural network in order to minimize the size of 3D models for making transmission over networks much faster. The main objective behind this compression is to simplify the 3D model and make handling the large size of 3d objects much easier for other processes. Even the process of rendering, digital watermarking, etc., will be faster and more efficient

6-tert-Butyl-4-[(4-hy­dr­oxy­methyl-2H-1,2,3-triazol-2-yl)meth­yl]-2H-chromen-2-one. Corrigendum

In the paper by El-Khatatneh et al. [IUCrData (2016), 1, x161618], the scheme and chemical name in the title are corrected

6-tert-Butyl-4-[(4-hy­dr­oxy­methyl-2H-1,2,3-triazol-2-yl)meth­yl]-2H-chromen-2-one

In the title compound, C\sb 17H\sb 19N\sb 3O\sb 3, the triazole ring and the chromene ring system maximum deviation = 0.018(2){\AA} for the O atom bridged {\it via} a methyl{\-}ene C atom, are inclined to one another by 73.2(1){$^\circ$}. In the crystal, mol{\-}ecules are linked by O{---}H{$\cdots$}N hydrogen bonds, forming zigzag chains along 001. The chains are linked by C{---}H{$\cdots$}O hydrogen bonds, forming layers parallel to (010), and these layers are linked by C{---}H{$\cdots$}{$\pi$} and {$\pi$}{--}{$\pi$} inter{\-}actions intercentroid distance = 3.557(1){\AA}, forming a three-dimensional newwork. The hy{\-}droxy{\-}methyl group at the 4-position of the triazole ring is disordered over two sets of sites, with a refined occupancy ratio of 0.418(11):0.584(11)

4-[(4-Hy­dr­oxy­methyl-2H-1,2,3-triazol-2-yl)meth­yl]-6-iso­propyl-2H-chromen-2-one

In the title compound, C\sb 16H\sb 17N\sb 3O\sb 3, the chromene ring is planar, with a maximum deviation of 0.017(4)Å for the ring O atom. The triazole and the chromene rings, bridged by a methyl\-ene C atom, are inclined to one another by 78.3(2)\circ. In the crystal, methyl\-ene—triazole C—-H⋅sN hydrogen bonds lead to the formation of helical supra\-molecular chains along the \it b axis. The sample was refined as an inversion twin. The terminal methyl\-hydroxy group is disordered over two sets of sites site occupancy = 0.610(13) for the major component

4-(4-Hy{\-}droxy{\-}meth{\-}yl-2{\it H}-1,2,3-triazol-2-yl)methyl-6,8-dimethyl-2{\it H}-chromen-2-one

In the title compound, C\sb 15H\sb 15N\sb 3O\sb 3, the dihedral angle between the triazole ring and coumarin ring system r.m.s. deviation = 0.040{\AA} is 77.40(6){$^\circ$}. The O atom of the hy{\-}droxy{\-}methyl group deviates from the triazole ring plane by 1.345(1){\AA}. In the crystal, inversion dimers linked by pairs of O{---}H{$\cdots$}O hydrogen bonds generate {\it R}{\sp 2}{\sb 2}(22) loops; C{---}H{$\cdots$}O and C{---}H{$\cdots$}N inter{\-}actions link the dimers into a three-dimensional network