964400
Arithmetic coding with dual symbol sets and its performance analysis
In this paper, we propose a novel adaptive arithmetic coding method that uses dual symbol sets: a primary symbol set that contains all the symbols that are likely to occur in the near future and a secondary symbol set that contains all other symbols. The simplest implementation of our method assumes that symbols that have appeared in the previously are highly likely to appear in the near future. It therefore fills the primary set with symbols that have occurred in the previously. Symbols move dynamically between the two symbol sets to adapt to the local statistics of the symbol source. The proposed method works well for sources, such as images, that are characterized by large alphabets and alphabet distributions that are skewed and highly nonstationary. We analyze the performance of the proposed method and compare it to other arithmetic coding methods, both theoretically and experimentally. We show experimentally that in certain contexts, e.g., with a wavelet-based image coding scheme that has appeared in the literature, the compression performance of the proposed method is better than that of the conventional arithmetic coding method and the zero-frequency escape arithmetic coding method.
1450773
Multiresolution video watermarking using perceptual models and scene segmentation
We introduce a watermarking procedure to embed copyright protection into digital video. Our video dependent watermarking procedure directly exploits the masking and temporal properties to embed an invisible and robust watermark. The watermark consists of static and dynamic temporal components that are generated from a temporal wavelet transform of the video scenes. To generate the watermark, the resulting wavelet coefficient frames are modified by a perceptually shaped pseudo-random sequence representing the author. The noise-like watermark is statistically undetectable to thwart unauthorized removal. Furthermore, the author representation resolves the deadlock problem. The multiresolution watermark may be detected on single frames without knowledge of the location of the frames in the video scene. We demonstrate the robustness of the watermarking procedure to several video distortions.
5048240
Current state of the art, challenges and future directions for audio watermarking
Transparent data embedding algorithms embed binary streams in host multimedia signals. The embedded data is perceptually inaudible to maintain the quality of the source data. The embedded data can add features to the host multimedia signal or provide copyright protection. We review developments and requirements in transparent data embedding techniques for audio signals. We describe our latest audio embedding algorithm and include experimental results indicating robustness to low bit rate MPEG-Layer 3, AAC, and Dolby AC-3 coding. We conclude with a discussion of future research directions.
32302991
Image coding by folding
We propose an image coding algorithm which employs data hiding techniques to "fold" an image into itself. Data hiding is a process of encoding extra information into a host image by making small modifications to its pixels. In our approach, an image is split into two parts of equal size: a host image and a residual image. The residual image is compressed into a bit stream and then embedded into the host image. The host image, which is 50% of the size of the original image, is coded using standard compression techniques. The embedded data does not increase the bit rate of the coded image. As a result, one may code only 50% pixels of the original image and still have perfect reconstruction. Experimental results indicate that the algorithm has a lot of potential in image coding.
27551113
Creating a Large-Scale Digital Library for Georeferenced Information
12614266
SVision: A Network Host-Centered Anomaly Visualization Technique
We proposed a technique merged from a combination of both anomaly and graphical methods, for intrusion detection. The network is pictured as a community of hosts that exchange messages among themselves. Our aim is to graphically highlight those hosts that represent a possible threat for the network, so that a network administrator will be able to further explore the anomaly and decide upon the responses that are appropriate. We choose to test our view against the DARPA 99 intrusion detection and evaluation dataset since it provides labels which we can use to monitor our system. Experiments show our visualization technique as a possible alternative for detection of network intrusions, in particular Denial of Service (DoS) and Distributed-DoS attacks such as Ping Of Death, UDP storm, SSH Process Table, and Smurf, to name a few.
6431667
Performance Analysis of Verification-Based Decoding for Packet-Based LDPC Codes over Binary Symmetric Channel
In this paper, we propose a statistical model to analyze the performance of verification-based algorithm (VA) for packet-based low-density parity-check (LDPC) codes over binary symmetric channel (BSC). In contrast to the analysis of VA in the literature, we propose to take the false verification into consideration. For a given ensemble of LDPC codes and channel parameters, the proposed analysis model gives an efficient way to find the average performance of packet-based LDPC codes with verification-based decoding. Through numerical results, we find that the proposed method can provide a close estimation of frame error rate (FER) for packet-based LDPC codes with verification-based decoding over BSC for all crossover probabilities of practical interests.
19034041
Study on Agent-Based Parts Resource Application System for Commercial Design
An effective way of retrieving components is needed in order to make the implementation of product commercial development activity. In this paper, the components resource application method based on the software agent is proposed first. Then, on the base of comparison to the product commercial design components resources application system and the traditional supply chain system, three kind of application patterns based on the present network components resources are analyzed: the on-line purchase pattern, the on-line inquiry pattern and the on-line assign pattern. Then, according to the commercial development characteristic, the concrete structure of software agent suit to the commercialization performance is given. Corresponding, the components coding agent, the solid - commercial mapping and optimizing agent as well as managing agent are designed. From the initial period geometrical modeling, the intermediate stage commercial design as well as the entire process design management, the analysis of these three aspects have been carried on separately. In the end, the research work indicated that, the agent technology is one effective application method used to realizing the magnanimous components data analysis over the network
15174288
Create a large-scale digital library for geo-referenced information
One of the most challenging research issues for geospatial collections is to develop techniques to support fuzzy, conceptbased, geographic information retrieval (GIR). Based on an artificial intelligence approach, this project presents a Geospatial Knowledge Representation System (GKRS) prototype system that integrates multiple multimedia (textual and image) knowledge sources to support concept-based GIR. Based on semantic network and neural network representations, GKRS loosely couples different knowledge sources and adopts spreading activation algorithms for concept-based knowledge inferencing. Both textual analysis and image processing techniques have been employed to create textual and visual geographical knowledge structures. This project suggests a framework for developing a complete GKRS-based system and describes in detail the prototype.