Near-perfect correlation functions based on zero-sum digital projections

Imants Svalbe

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    3 Citations (Scopus)


    Minimal projective ghost functions make good watermark labels for embedding into images. Although fragile to hacking attacks, they are near-to-invisible because of their distributed, random appearance and their binary, zero-mean statistics. They have the strong correlation properties needed to extract a low-intensity watermark from bright image data. We present a method to embed, concurrently, up to (p-1)/2 independent minimal ghosts within the same pxp image space, where p is prime. Compounding ghosts inside the same pxp space increases, by (p-1)/2, the robustness with which these watermarks can be recovered. This result then approaches the optimal peak correlation result obtainable using 2D perfect or near-perfect sequences. However, unlike perfect sequences, minimal ghosts are simple to construct and compound. A large number of independent compounded minimal ghosts can be generated for each prime p, thus each watermark is sufficiently individual to prevent confusion when multiple labels are present.
    Original languageEnglish
    Title of host publication2011 International Conference on Digital Image Computing: Techniques and Applications
    EditorsAndrew Bradley, Paul Jackway, Yaniv Gal, Olivier Salvado
    Place of PublicationUSA
    PublisherIEEE, Institute of Electrical and Electronics Engineers
    Number of pages6
    ISBN (Print)9781457720062
    Publication statusPublished - 2011
    EventDigital Image Computing Techniques and Applications 2011 - Sheraton Noosa Resort & Spa, Noosa Sunshine Coast, Australia
    Duration: 6 Dec 20118 Dec 2011
    Conference number: 13th (Proceedings)


    ConferenceDigital Image Computing Techniques and Applications 2011
    Abbreviated titleDICTA 2011
    CityNoosa Sunshine Coast
    OtherThe International Conference on Digital Image Computing: Techniques and Applications (DICTA) is the main Australian Conference on computer vision, image processing, pattern recognition, and related areas. DICTA was established as a biannual conference in 1991 and became an annual event in 2007. It is the premiere conference of the Australian Pattern Recognition Society (APRS).
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    • discrete projection
    • discrete Radon transforms
    • image correlations
    • Image labelling

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