| 1. |
- Georgakis, Apostolos, 1975-, et al.
(författare)
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Spread spectrum wavelet watermarking system
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Lately attention has been focused on wavelet-based watermarking because of its compatibility with the newly developed JPEG 2000 image compression scheme. The major setback associated with wavelet-based watermarking is its vulnerability to geometric distortion caused by the lack of invariance property of wavelet transform. The domain of digital watermarking focused on spread spectrum based technique because of its excellent antijamming feature in wireless communication. However existing digital watermarking systems based on spread spectrum technique are yet to replay the anti-jamming feature in wireless communication, hence have not yielded the desired fully robust characteristics. Existing geometric invariant spread spectrum watermarking systems are complex, difficult to implement and unreliable. In our view this is due to inability of researchers to faithfully implement spread spectrum principle. Our investigation showed that most spread spectrum based watermarking faithfully implement the embedding process but fail to despread the signal before detection as required in a typical wireless spread spectrum communication. In this project we propose a simple spread spectrum wavelet watermarking system that is secure, tuneable and fully robust to all known forms and severities of attacks. The novel feature of our watermarking system design is its model as a communication system with the original (host) image representing the communication channel, the watermark represent the message (base band) signal and the legal and malicious attacks represent the noise, interference or jamming of the message signal. Experimental results from our system showed a replay of the excellent anti-jamming feature of spread spectrum communication technique and confirm the superior performance of our system over existing correlation-based spread spectrum wavelet watermarking system.
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| 2. |
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| 3. |
- Abu-Hamam, Anas, 1977-, et al.
(författare)
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Understanding Web Users Behaviour From A Web Video Camera
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- To develop a Real-Time system, which can capture and track the web user’s head motion. Based on the head motion information, the system should be able to identify whether the user is interested in the current homepage or not. A future system property would be to find out in which area of the homepage the user’s interest is moving.
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| 4. |
- Georgakis, Apostolos, 1975-, et al.
(författare)
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Document distances using the Zipf distribution and a novel metric
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A novel metric is proposed in the present report for the evaluation of the goodness-of-fit criterion between the distribution functions of two samples. We extend the usage of the proposed criterion for the case of the generalized Zipf distribution. Detailed mathematical analysis of the proposed metric, which is embodied in a hypothesis testing, is also provided.
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| 5. |
- Georgakis, Apostolos, 1975-, et al.
(författare)
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Web prefetching through automatic categorization
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The present report provides a novel transparent and speculative algorithm for content based web page prefetching. The proposed algorithm relies on a user profile that is dynamically generated when the user is browsing the Internet and is updated over time. The objective is to reduce the user perceived latency by anticipating future actions. In doing so the adaboost algorithm is used in order to automatically annotate the outbound links of a page to a predefined set of “labels”. Afterwards, the links that correspond to labels relevant to the user’s preferences are pre-fetched in an effort to reduce the perceived latency when the user is surfing the Internet. A comparison between the proposed algorithm against two other pre-fetching algorithms yield improved cache-hit rates given a moderate bandwidth overhead.
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| 6. |
- Söderström, Ulrik, 1978-, et al.
(författare)
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Customizing Lip Video into Animation for Wireless Emotional Communication
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Universal Multimedia Access (UMA) engines are used to adapt the media content to suite different environments.The adaptation decision for content used over wireless networks is heavily dependent on the bandwidth needs since the transmission cost over wireless networks is high. We customize lip video into lip animations and through tests we challenge the assumption that the quality is reduced when the transmission cost is reduced. We show that animations are comparable with video when considering human emotion understanding and comparable with audio only when considering transmission cost. We argue that it is important to consider human cognitive and perceptive factors in the decision stage of a UMA engine. This can both improve the user’s perceived quality and lower the transmission cost.
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| 7. |
- Söderström, Ulrik, 1978-, et al.
(författare)
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Emotion recognition and estimation from tracked lip features
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Humans transmit and display information through the visual image of our lips; information about our speech and our emotions and expressions. By being able to track the movement of the lips, computers can make use of the visual part of the information. This information can be used for multiple purposes. Other research has mainly been focused on using lip tracking for speechreading, but here we focus on how to make use of tracked lip features for emotions. We have found that people are better at interpreting basic emotions displayed through an animation of lips than interpreting the same emotions displayed through a real video sequence that shows the lower part of the face. We have successfully transferred three basic emotions from visual information into information from another modality; touch.
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| 8. |
- ur Réhman, Shafiq
(författare)
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Lip Localization and Tracking: A Survey
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We explore the classification and performance of various techniques for the human-lip extraction and tracking in video sequence. This survey identifies the potential challenges and overview the recent techniques. Considering the previous efforts, it will discuss the limitation and points out performance parameters for lip region localization and tracking techniques. The scope of this survey is limited to lip feature extraction techniques and does not include human face detection or recognition. It concludes with some thought of new direction in the field.
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| 9. |
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| 10. |
- Yao, Zhengrong, 1971-, et al.
(författare)
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A Networked Yawn Detector
- 2003
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The driver’s mental state could be estimated from visual clues. The typical driver’s fatigue event could be detected or predicted by the dynamic facial expression events such like yawn. This paper demonstrate a networked surveillance system, where the driver’s facial expression parameters are extracted from real time video of face in car and sent via wireless network to a surveillance center, where the parameters could be evaluated to find if the driver is under fatigue situation. The parameter extraction using the Model-based coding (MBC) technique. A Hidden Markov Model (HMM) is used for recognizing the yawn event which characterize a typical fatigue event.A prototype of such a networked system was set up and subjected to user tests. Promising results from user tests and their subjective evaluations are reported.
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