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Personal computers today have 802.11 (b/a/g) -based wireless connectivity. By connecting laptops to a projector wirelessly, multiple persons could connect to the projector and present the content on their laptops. This typically requires another personal computer at the projector end that is wirelessly connected to the laptop and which receives, decodes, and renders a compressed version of what was...
The technology behind H.264, a joint video coding standard by ITU-T and ISO, offers a significant reduction in bit-rate over earlier standards-based technologies such as MPEG-2 and MPEG-4. Such a compression efficiency advantage spurs its adoption in personal video recorders and in network edge servers that stream content over various last mile solutions that have limited bandwidth. This requires...
Web-based distance learning has become more popular and convenient, and it provides a flexible environment for learners. However, it is hard for teachers to design the distance course and assess students' learning. To overcome this drawback, a systematic assessment mechanism is proposed to enhance interaction between students and teachers. The theory-of-concept and influence diagram are combined together...
Pocket devices are dominated in size which makes them the perfect platform for mobile learning. Several researches propose how distance education can be realized on pocket devices. We demonstrate the implementation of the adaptive pocket SCORM (scalable content object reference model) reader. Our proposed pocket SCORM reader is able to load SCORM compatible courseware. Furthermore, we introduce our...
There are many noise sources for images. Images are, in many cases, degraded even before they are encoded. Previously, we focused on Poisson noise (Huang, X. et al., IEEE Int. Conf. on Multimedia and Expo, vol.1, p.593, 2003). Unlike additive Gaussian noise, Poisson noise is signal-dependent and separating signal from noise is a difficult task. A wavelet-based maximum likelihood method for a Bayesian...
Background subtraction algorithms are critical to many video recognition/analysis systems and have been studied for decades. Most of the algorithms assume that the camera is fixed. We propose a background subtraction algorithm that works when a shaking camera is present. In this algorithm, the input frames are compensated and compared with the given reference frame to separate foreground objects from...
Vector representation of graphics has the advantage that the image can be displayed at any size. When the resolution of a bitmap image is changed, the lack of a line segment arises. In addition, moire occurs when the resolution of an image with halftone dots is changed. We propose a new technique to convert a binary image with halftone dots into its vector representation. Resolution conversion of...
This paper proposes an adaptive binarization method, based on the criterion of maximizing local contrast, for document image analysis. The proposed method has overcome, to a large extent, the general problems of poor quality document images, such as non-uniform illumination, undesirable shadows and random noise. It was tested against a variety of challenging images, and the experimental results are...
The background subtraction algorithm is a frequently-used object segmentation technique because of its algorithmic simplicity. However, we show that, for general rotational camera-motion, it is impractical, or even impossible, to use a single background image. As a solution, we propose to use multi-sprite backgrounds which enables processing of arbitrary rotational camera-motion. The paper describes...
The automatic property measurement of solar flares through their complete cyclic development is valuable in the studies of solar flares. From the analysis of solar H/spl alpha/ images, we are able to use a support vector machine (SVM) to automatically detect flares, and apply image segmentation techniques to compute the properties of solar flares. We also present our solution for automatically tracking...
We propose a new algorithm, the multi-view expectation and maximization algorithm (multi-view EM), to deal with real-world learning problems where there are some natural split of features. Multi-view EM does feature split in the same manner as co-training and co-EM, two successful semi-supervised learning algorithms in text learning tasks, but it considers the multi-view learning problem in the framework...
This work presents a novel fast method for line segment extraction, based on a chain code representation of edge maps. It has a parallel nature and can be employed on parallel machines. In the first phase it breaks the macro chains into several micro chains after applying shifting, smoothing and differentiating. The micro chains are then approximated by straight line segments. In the second phase,...
Blurring artifacts occur in low bit-rate wavelet images or in video coding. They manifest themselves as blurred patches within textured regions. As such, it is possible to exploit this texture level correlation between adjacent image regions to reconstruct the lost texture. In order to automatically identify the blurred patches, and use valid source regions to draw textures from their surroundings...
Single-sensor digital still cameras capture imagery with a color filter array in a way that each sensor pixel samples only one of the primary color values. To render a full-color image from CFA samples, the missing color values need to be interpolated from the neighboring samples. This process is commonly referred to as demosaicking. In this paper, we present two main contributions to demosaicking...
Restoration of color-quantized images is rarely addressed in the literature, especially when the images are color-quantized with halftoning. Direct applications of existing restoration techniques are generally inadequate to deal with this problem. A restoration algorithm based on simulated annealing is proposed to solve the problem. This algorithm makes a good use of the available color palette and...
We propose a fast codebook generation algorithm for entropy-constrained vector quantization (ECVQ). The algorithm uses the angular constraint and employs a suitable hyperplane to partition the codebook and image data in order to reduce the search area and accelerate the search process in the codebook design. This algorithm allows significant acceleration in the codebook design process. Experimental...
Joint source-channel decoding of variable length codes (VLC) for image and video streaming transmission over unreliable links, such as wireless networks, is a subject of increasing interest. Much more residual source redundancy can be exploited when both types of correlation: (i) the correlation between bits inside a VLC codeword as well as; (ii) the correlation between VLC codewords of a VLC sequence...
Conventional rate control schemes focus on the problem of finding an optimal quantization value for P- and B-frames. No rate control is available for the encoding of I-frames. This could pose big problems due to the large number of bits an I-frame could generate, and due to the fact that the number of bits varies drastically from sequence to sequence, depending on their image complexity. This problem...
We describe an efficient bit allocation algorithm using 2D interpolation of the rate-distortion (R-D) characteristics in a dependent coding environment for applications of one-way video. To solve the dependent coding problem, it is necessary to measure R-D data for all possible combination of quantization settings in the reference frame and the predictive frame. 2D interpolation of rate-distortion...
Quality fluctuation has a major negative effect on subjective video quality. A desirable single-pass frame-level constant-distortion bit allocation scheme is proposed in the paper for smooth video quality throughout the video sequence. The average distortion of previous coded frames is taken as the target distortion for the current frame. According to the linear rate control algorithm, the distortion...
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