June-Young Chang

Side Information Generation Using Extra Information in Distributed Video Coding

We address the hash-based side information generation problem in Distributed Video Coding (DVC). The side information plays an important role in DVC because more accurate side information is generated with less number of parity bits needed to successfully decode the Wyner-Ziv (WZ) frame. In hash-based side information generation, the encoder also generates and transmits some hash codes about the current WZ frame to help improve the quality of side information, especially when using motion extrapolation techniques. In the paper, hashes are designed using various types of extra information and their impacts on side information are examined.

A Novel Motion Compensated Frame Interpolation Method for Improving Side Information in Distributed Video Coding

In this paper, we address the side information generation problem in distributed video coding (DVC). To decode the current Wyner-Ziv frame, the DVC decoder usually generates side information by using motion compensated frame interpolation (MCFI) algorithms with neighboring decoded key frames. We survey some MCFI algorithms and side information generation methods based on MCFI. We also discuss our novel idea using edge information of decoded frames to generate more accurate interpolated frame. The experimental results show that it is reasonable to use edge information to improve side information at the decoder.

Motion Estimation Based on Temporal Correlations

To remove temporal redundancy contained in a sequence of images, motion estimation techniques have been developed. However, the high computational complexity of the problem makes such techniques very difficult to be applied to high-resolution applications in a real time environment. If a priori knowledge about the motion of the current block is available before the motion estimation, a better starting point for the search of an optimal motion vector can be selected. In this paper, we present a new motion estimation approach based on temporal correlations of consecutive image frames that defines the search pattern and the location of initial search point adaptively. Experiments show that, comparing with DS(Diamond Search) algorithm, the proposed algorithm is about 0.1 ∼ 0.5(dB) better than DS in terms of PSNR and improves as much as 50% in terms of the average number of search points per motion estimation.

Fuel economy validation of the smart microhybrid system for used cars

We developed a smart microhybrid system for used cars to improve fuel efficiency via the OBD-II interface. The proposed smart microhybrid system can accurately measure the amount of fuel that is saved by stopping engine idling and estimates the amount of fuel that is consumed when the engine begins to start. It automatically determines when is optimal to stop or start the engine using various driving status. The system was implemented and tested in a used car. Experimental results show that it outperforms conventional cars not equipped with the smart microhybrid system in fuel economy. We will massively reduce CO2 by using smart microhybrid systems and prove the possibility of the CDM (clean development mechanism) project.

Star-Mesh NoC based multi-channel H.264 decoder design

In this paper we described the architectural exploration of Star-Mesh NoC based multi-channel H.264 decoder. The Star-Mesh NoC is comprised of local star switch and global mesh switch. By analyzing data transfers among the processors, IPs, and memories, we partitioned IPs into clusters to map then to Star-Mesh NoC architecture. In order to enhance data parallelism and NoC utilization, H.264 decoder IPs with much data traffic are mapped to star switch and shared memory is connected to mesh switch where star switch connected to mesh switch with 1-hop. We explored several mapping architecture to achieve improvement of the system throughput.

Latency optimization for NoC design of H.264 decoder based on self-similar traffic modeling

In this article, we present analytical method to evaluate the NoC design of H.264 decoders latency based on the self-similar traffic models of all 12 IPs. The traffic models are generated by using the superposition of four 2-state Modulated Markov Poisson Process (MMPP) and the real traced data transaction between IPs. The optimization engine is utilized to automatically allocate IPs on the desired routers to achieve the minimal latency.

Anisotropic Diffusion for Preservation of Line-edges

In existing approaches, diffusion is performed in four directions (North, South, East, West) without specific conditions. Therefore, these methods have shortcomings of distorted with the existence of impulse noises. In this paper, a new anisotropic diffusion based on directions of line-edges is proposed to enhance preservation of line-edges together with removal of noises. In the proposed method, an edge detection mask is used to find the direction of a line-edge. As a result, when the magnitude of edge detection is large enough, there exists a line-edge. In the case of a line-edge, the weight of diffusion is selected adaptively according to the direction of the line-edge. The diffusion is based on 8-directions diffusion with emphasis on the line-edge direction. Experimental results show that the proposed method can eliminate noise while preserving contour of line-edges.