Browsing by Author "Ranmuthugala, MHP"

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    item: Conference-Abstract
    Chaos theory based cryptography in digital image distribution : visibility controlled image encryption scheme (ViCIEn)
    Ranmuthugala, MHP; Gamage, CD
    The amount of visual information available in digital format has grown exponentially in recent years due to the wide availability of digital equipments, changes in the way people socially interact by setting up community web pages, wide spread use of the Internet in all types of personal and business activities, pay-after-trial services of digital multimedia and developments in high speed transmission of digital images with high reliability. However, the wide accessibility of the Internet and its connected hosts and availability of technology to capture network traffic or penetrate hosts have made digital images vulnerable to unauthorized access while in storage and during transmission over a network. Hence users of the Internet and application that use or process digital images need to address security issues to protect commercial value of images and also ensure user privacy and other issues. The objective of the research presented in this paper focused on proposing an image encryption technique which is capable of encrypting an image effectively and securely with a predefined visibility level. The stipulated objective is achieved by employing 2D chaotic map called the Kaplan-Yorke map.
  • Thumbnail Image
    item: Thesis-Abstract
    Chaos theory based cryptography in digital image distribution : visibility controlled image encryption scheme (ViCIEn)
    Ranmuthugala, MHP; Gamage, C
    The amount of usual information available in digital format has grown exponentially in recent years due to the wide availability of equipments such as digital cameras and camera phones, changes in the way people socially interact by setting up community web pages, wide spread use of the Internet in all types of personal and business activities, and developments in high speed transmission of digital images with high reliability./ However, the wide accessibility of the Internet and its connected hosts and availability of technology to capture network traffic or penetrate hosts have made digital images vulnerable to unauthorized access while in storage and during transmission over a network. Hence users of the Internet and application that use or process digital images need to address security issues to protect commercial value of images and also ensure user privacy and other issues.
  • Thumbnail Image
    item: Article-Abstract
    Online Sinhala Handwritten Character Recognition on Handheld Devices
    Ranmuthugala, MHP; Pathiragoda, GDNC; Jayasundara, SHC; Dias, G; Karunananda, AS
    The online handwritten character recognition on handheld devices presents a challenging assignment due to the limited memory, processing and storage constraints. This paper presents an online handwritten character recognition process based on Non Deterministic Finite Automaton (NFA) and XML character pattern profiles for Sinhala alphabetic characters. The process models a character as a sequence of directional states and accumulates under a hierarchical XML tag structure. The NFA is used to construct valid Sinhala character combinations and to determine pattern search alternatives. Accuracy improvement and failure analysis models are used to achieve a recognition rate of 90% on run on discretely written Sinhala characters after adopting user specific customizations on character pattern profiles.