Lexicographical framework for image hashing with implementation based on DCT and NMF

  • Authors:
  • Zhenjun Tang;Shuozhong Wang;Xinpeng Zhang;Weimin Wei;Yan Zhao

  • Affiliations:
  • School of Communication and Information Engineering, Shanghai University, Shanghai, People's Republic of China 200072;School of Communication and Information Engineering, Shanghai University, Shanghai, People's Republic of China 200072;School of Communication and Information Engineering, Shanghai University, Shanghai, People's Republic of China 200072;School of Communication and Information Engineering, Shanghai University, Shanghai, People's Republic of China 200072;School of Communication and Information Engineering, Shanghai University, Shanghai, People's Republic of China 200072

  • Venue:
  • Multimedia Tools and Applications
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

Image hash is a content-based compact representation of an image for applications such as image copy detection, digital watermarking, and image authentication. This paper proposes a lexicographical-structured framework to generate image hashes. The system consists of two parts: dictionary construction and maintenance, and hash generation. The dictionary is a large collection of feature vectors called words, representing characteristics of various image blocks. It is composed of a number of sub-dictionaries, and each sub-dictionary contains many features, the number of which grows as the number of training images increase. The dictionary is used to provide basic building blocks, namely, the words, to form the hash. In the hash generation, blocks of the input image are represented by features associated to the sub-dictionaries. This is achieved by using a similarity metric to find the most similar feature among the selective features of each sub-dictionary. The corresponding features are combined to produce an intermediate hash. The final hash is obtained by encoding the intermediate hash. Under the proposed framework, we have implemented a hashing scheme using discrete cosine transform (DCT) and non-negative matrix factorization (NMF). Experimental results show that the proposed scheme is resistant to normal content-preserving manipulations, and has a very low collision probability.