IlHong Shin

Image upsizing with adaptive Wiener filtering method using self-prediction

In this paper, a straightforward and effective method for image upsizing is presented; upsizing is considered to be an essential operation in image processing. The Wiener filtering method is a well-known optimal framework for signal prediction, which provides information of original and degraded signals. In image upsizing, the Wiener filtering framework is not valid because of the missing information about the upsized target image. The proposed method employs a self-prediction scheme where a down-sampled image of the original image is used for the Wiener filter prediction and the obtained filter coefficient is actually used in the upsizing of the original image. The experimental validation shows improvement in both visual and objective quality.

Implementation of the cloud gaming platform with adaptive bitrate streaming

There are still many technical challenges to provide a better users experience in the field of cloud-based gaming service. We focus on an adaptive streaming technology in this paper. We describe the implementation of platform for cloud-based gaming service, delivering virtualized gaming contents adaptively according to variations of available network bandwidth. And we show the measured latency according to changes of the bandwidth at users access network.

Frame splitting approach for adaptive up-sampling in scalable video coding

Paper proposes an improvement method for spatial scalable video coding (H.264 SVC), which adopts multiple upsizing filter coefficient transmission for efficient inter-layer prediction. According to previous studies, adaptive upsizing filtering method by coefficient transmission leads a little coding performance gain. In this paper, transmission scheme of multiple adaptive filter coefficients were taken by dividing a frame selectively. In experimental results, rate-distortion performance and computational complexity of the proposed method are analyzed for various video sequences. The proposed method achieves improvement in coding efficiency of spatial scalable video coding.

Two-pass approach for fast block-type decision in H.264 encoder

This paper proposes a fast encoding method for H.264, which adopts two-pass approach for block-type decision. In the first pass, one candidate blocktype is determined from seven inter block types using limited search range. The second pass finally decides the best blocktype from the candidate inter blocktypes and intra blocktypes. In experimental results, rate-distortion performance and computational complexity of the proposed method are analyzed for two video sequences. The proposed method achieves remarkable improvement in computational complexity with only small degradation in PSNR compared to the full-motion estimation (ME) method.

Cloud-based 3D gaming system for smart TV

Cloud gaming service has recently received a lot of attention. However, there are still many technical challenges to be solved in order to provide the cloud-based commercial services for high-quality games. Latency is one of the most important issues to provide a good user experience. In this paper, we describe the implementation of cloud-based gaming service system for smart TV. And we show the latency comparison on game agents.

Improvement of the spatial scalable video codec

The down-sampling method generally employs strong anti-aliasing for visual friendliness. However, scalable video coding reuse base layer representation for compression efficiency. The proposed method applies down-sampling method at the encoder, where strong anti-aliasing did not be considered. The adaptive filtering technique is exploited for reducing aliasing effect at the decoder. The experimental result with intra frame coding shows proposed method improves PSNR, and reduces bitrate.

Visually improved DCT based down-sampling method for H.264 SVC

In a scalable video coding (SVC), spatial down/up-sampling of video sequences is an essential process for spatial scalability. We propose a spatial down-sampling method based on the DCT, with which down-sampling of H.264 SVC can be fast and visually improved. For aliasing reduction, an optimized frequency weighting parameter is used for making a spatial domain down-sampling filter for DCT. A fast algorithm with matrix decomposition and fast DCT makes proposed method applicable to scalable video encoder.