TaeYong Kim

Network traffic analysis and modeling for games

A number of papers have been proposed for the purpose of analyzing the traffic data of network game and providing the models recently. The traffic characteristics of network games are different according to the game genres, and the traffic is affected by player number and the in-game behaviors. In this paper, we develop the dedicated tool NetGame Sniffer for measurement and analysis of network game traffic, and measure the traffic of Quake and World of Warcraft. We analyze and compare the traffic characteristics according to the number of players and user actions, and propose the game traffic models and practical uses of the models. The analysis and models of network game traffic are can be used for effective network simulation, performance evaluation and the design of network games.

Real-time user interface using particle filter with integral histogram

In order to apply a vision technique to the real-time user interface, a fast and effective method of tracking human face and hands, and recognizing human pose by inverse kinematics is suggested in this paper. The suggested method shows that when observation likelihood is estimated, it is able to process in high speed proportional to numbers of samples with the integral histogram. The experiment results show that the method using integral histogram is faster than the method based on existing color histogram, while keeping similar recognition performance. The proposed user interface system is ideally suitable for gaming devices that utilizes user gesture and pose as control input in real-time.

Shape-Based image retrieval using invariant features

In this paper we propose an accurate shape-based image retrieval method which uses both types of moment invariants and Fourier descriptors. The method first excludes irrelevant images of different appearances using the region-based moment invariant features and then, using Fourier descriptors, the method increases the retrieval effectiveness substantially. The retrieval method was tested on our shape databases and the search accuracy was compared with those of Fourier descriptors and moment invariants. The hybrid method of using both boundary-based Fourier descriptor and region-based moment invariants provides much better performance than other similarity method.

Variable block-based deblocking filter for H.264/AVC on low-end and low-bit rates terminals

H.264/AVC supports variable block motion compensation, multiple reference frames, 1/4-pixel motion vector accuracy, and in-loop deblocking filter, compared with previous video coding standards. While these coding techniques are major functions for video compression improvement, they lead to high computational complexity at the same time. For the H.264 video coding techniques to be actually applied on low-end/low-bit rates terminals more extensively, it is essential to improve the coding efficiency. Currently the H.264 deblocking filter, which can improve the subjective quality of video, is hardly used on low-end terminals due to computational complexity. In this paper, we propose an enhanced method of deblocking filter that efficiently reduces the blocking artifacts occurring during the low-bit rates video coding. In the variable block-based deblocking filter (VBDF) proposed in this paper, the temporal and spatial characteristics of moving pictures are extracted using the variable block-size information of motion compensation, the filter mode is classified into four different modes according to the moving-picture characteristics, and the adaptive filtering is executed in the separate modes. The proposed VBDF can reduce the blocking artifacts, prevent excessive blurring effects, and achieve about 30-40% computational speedup at about the same PSNR compared with the existing methods.

AR table tennis: a video-based augmented reality sports game

Interactions in augmented reality systems are based on human gestures rather than classical input devices. Due to the instability of the current gesture recognition technologies, the previous development processes of augmented reality games have introduced many ad hoc methods to handle the shortcomings, and the game architectures have become highly irregular and inefficient. This paper describes an efficient development methodology for gesture-based augmented reality games through prototyping a table tennis game with a gesture interface. We also verify the applicability of the prototyping mechanism by implementing and demonstrating the augmented reality table tennis game played with real rackets wherein the implementation requires the real-time tracking of real rackets to allow fast movements and interactions without delay.

IRED gun: infrared LED tracking system for game interface

In this paper, we propose an infrared LED tracking system called IRED Gun, which is designed for the game gun interface. The conventional systems are practically restricted by physical environment and have a lot of problems. We suggest the IRED Gun system to solve these problems. Unlike conventional systems, our tracking system uses three infrared LED lights attached on a monitor, and enables a user to interact with a game. In addition, our system calibrates reliable aim coordinates along the target position of a user by an error correction method based on an aim correction model. Therefore, our infrared LED tracking method allows users freely move in front of a monitor.

Dynamic Bit-Rate Allocation with Fuzzy Measures for MPEG Transcoding

In this paper, we propose a dynamic bit-rate allocation algorithm for MPEG transcoding. The method consists of a bit-rate allocation with fuzzy measures and a least-distortion bit-rate reduction. Fuzzy measures are calculated by the code length, the discontinuity bluntness, and the neighborhood momentum in each DCT block. These measures are summed with weights and form a reduction fuzziness to indicate the degree of plausible reduction. Using the reduction fuzziness, each DCT block is filtered by the least-distortion reduction method to adjust the bit-rate for a target bandwidth. In the experiment, we show the results that the transcoded video quality by the method is better and the bandwidth is more regular than those of existing methods in both visually and quantitatively.

Enhanced video complexity analysis with audio features

In this paper, we propose an enhanced method of video complexity analysis with audio features. By using the audio features related with visual features, we improved the performance of video complexity analysis and verified the effective values on applying H.264 Rate-Control.

Effective algorithm for imbalance reduction in stereo image pair

This paper presents an effective approach to resolve the imbalance in stereo image pairs by using histogram specification and structural similarity index. Specifically, we adjust a given target image similar to the reference one through an estimated balancing function based on the geometrical structure and its color information.

Discontinuity enhancement using fuzziness in DCT blocks

Though there have been many methods to detect features in spatial domain, in the case of a compressed image it has to be decoded, processed and encoded again. Alternatively, we can manipulate a compressed image directly in the Discrete Cosine Transform (DCT) domain that has been used for compressing videos or images in the standards like MPEG and JPEG, and we have proposed a model-based discontinuity evaluation technique in the DCT domain that has problems in the rotated or non-ideal discontinuities. In this paper, we propose a fuzzy filtering technique that consists of height fuzzification, direction fuzzification, and fuzzy filtering of discontinuities. The enhancement achieved by the fuzzy filtering includes the linking, thinning, and smoothing of discontinuities in the DCT domain. Although the detected discontinuities are rough in a low-resolution image for the size (8 × 8 pixels) of the DCT block, experimental results show that this technique is fast and stable to enhance the quality of discontinuities.