Chaw-Seng Woo

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Medical images in digital form must be stored in a secure way to preserve stringent image quality standards and prevent unauthorised disclosure of patient data. This paper proposes a multiple watermarking method to serve these purposes. A multiple watermark consists of an annotation part and a fragile part. Encrypted patient data can be embedded in an(More)
The essential performance metrics of a robust watermark include robustness, imperceptibility, watermark capacity and security. In addition, computational cost is important for practicality. Wavelet-based image watermarking methods exploit the frequency information and spatial information of the transformed data in multiple resolutions to gain robustness.(More)
The demand for automatically classification of medical X-ray images is rising faster than ever. In this paper, an approach is presented to gain high accuracy rate for those classes of medical database with high ratio of intraclass variability and interclass similarities. The classification framework was constructed via annotation using the following three(More)
Image segmentation techniques have been an invaluable task in many domains such as quantification of tissue volumes, medical diagnosis, anatomical structure study, treatment planning, etc. Image segmentation is still a debatable problem due to some issues. Firstly, most image segmentation solutions are problem-based. Secondly, medical image segmentation(More)
Many image segmentation solutions are problem-based. Medical images have very similar grey level and texture among the interested objects. Therefore, medical image segmentation requires improvements although there have been researches done since the last few decades. We design a self-learning framework to extract several objects of interest simultaneously(More)
The rapid development of technologies and steadily growing amounts of digital information highlight the need of developing an accessing system. Content-based image indexing and retrieval has been an important research area in computer science for the last few decades. The approaches of content-based image retrieval using low level features such as colour,(More)
Content-based image retrieval techniques have been extensively studied for the past few years. With the growth of digital medical image databases, the demand for content-based analysis and retrieval tools has been increasing remarkably. Blood cell image is a key diagnostic tool for hematologists. An automated system that can retrieved relevant blood cell(More)
Digital watermarking techniques have been proposed to protect the copyright of multimedia data. Robustness against geometric distortion is one of the most important issues to be solved to increase the robustness of digital image watermarking systems. Such attacks are very simple to implement, so they can defeat most existing watermarking algorithms without(More)