human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "a dwt dct and svd based watermarking technique to protect the image piracy"
  Abstract: With the rapid development of information technology and multimedia, the use of digital data is increasing day by day. So it becomes very essential to protect multimedia information from piracy and also it is challenging. A great deal of Copyright owners is worried about protecting any kind of illegal repetition of their information. Hence, facing all these kinds of problems development of the techniques is very important. Digital watermarking considered as a solution to prevent the multimedia data. In this paper, an idea of watermarking is proposed and implemented. In proposed watermarking method, the original image is rearranged using zigzag sequence and DWT is applied on rearranged image. Then DCT and SVD are applied on all high bands LH, HL and HH. Watermark is then embedded by modifying the singular values of these bands. Extraction of watermark is performed by the inversion of watermark embedding process. For choosing of these three bands it gives facility of mid-band and pure high band that ensures good imperceptibility and more robustness against different kinds of attacks.

Connected through hyperedge HE-1 (induced by source paper "a dct and svd based watermarking technique to identify tag"):
  with members:
    - "improved watermarking scheme using discrete cosine transform and schur decomposition"
    - "digital watermarking for image authenticationbased on combined dct dwt and svd transformation"
    - "improved robust dwt watermarking in ycbcr color space"
    - "an approach of digital image copyright protection by using watermarking technology"
    - "perceptual copyright protection using multiresolution wavelet based watermarking and fuzzy logic"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.MM(Multimedia)