human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Reversible data hiding"
  Abstract: This paper presents a novel reversible data hiding algorithm, which can recover the original image without distortion from the marked image after the hidden data have been extracted. This algorithm utilizes the zero or the minimum point of the histogram and slightly modifies the pixel values to embed data. It can embed more data as compared to most of the existing reversible data hiding algorithms. A theoretical proof and numerous experiments show that the PSNR of the marked image generated by this method is always above 48 dB, which is much higher than other reversible data hiding algorithms. The algorithm has been applied to a wide range of different images successfully. Some experimental results are presented to demonstrate the validity of the algorithm.

Connected through hyperedge HE-1 (induced by source paper "Secure spread spectrum watermarking for multimedia"):
  with members:
    - "Watermarking Document Images with Bounding Box Expansion"
    - "Quantization Index Modulation Methods for Digital Watermarking and Information Embedding of Multimedia"
    - "Image steganalysis based on moments of characteristic functions using wavelet decomposition, prediction-error image, and neural network"
    - "Multiresolution scene-based video watermarking using perceptual models"

Connected through hyperedge HE-2 (induced by source paper "A reversible data hiding method with contrast enhancement for medical images"):
  with members:
    (none)

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science