Architecture and Algorithm Design for Image Coding and Scalable Video Application
Date Issued
2009
Date
2009
Author(s)
Pan, Chia-Ho
Abstract
Multimedia applications are more and more popular in our life as the rapid progress of image sensor, display devices, communication, VLSI manufacture, computing engines, and image/video coding standards. Many advanced multimedia applications require image and video compression technology with higher compression ratio and better visual quality. High quality, high compression rates of digital image/video, and low computational cost are important factors in many areas of consumer electronics. These requirements usually involve computationally intensive algorithms imposing trade-offs between quality, computational resources, and throughput. Hence, the researches of hardware-oriented algorithms and VLSI architectures push the progress of multimedia applications. This dissertation has two main purposes: to propose VLSI architectures for efficient implementation of the image coding systems and to provide algorithm designs of scalable video application systems for the emerging requirement in real multimedia applications.n the first part, we describes system analysis and architecture design of JPEG XR encoder. We proposed two chip implementations for JPEG XR image coding.Firstly, a 4:4:4 lossless/lossy symbol-based JPEG XR encoder is implemented on a 3.222 mm$^{2}$ with 90nm CMOS technology dissipating 95.7 mW at 0.9 V and 62.5 MHz. It is capable of processing 34.1 Mega samples within one second for lossless/lossy coding. The timing schedule and pipelining of color conversion, pre-filter, PCT and quantization modules are well designed. In order to prevent accessing the coefficients from off-chip memory, n on-chip SRAM is designed to buffer the coefficients. We use well arranged sub-pipeline timing schedule for the implementation of the entropy encoding module to increase the throughput about 3 times. This design is dedicated for the DSC and digital frame application. The another chip design is channel parallel JPEG XR encoder. An five-stage block pipelined architecture with proposed system scheduling supports real-time 4:4:4 full-HD(1920x1080p) lossless/lossy processing ability. We analysis the dependency of RLE and Flexbits modules and adopt multi-symobl architecture to reduce the processing cycles. It is implemented on 9.61 mm$^{2}$ with 0.18 um CMOS technology and 81 MHz. The 187 Mega samples/sec throughput are achieved by proposed system scheduling, high degree of parallelism, reducing memory access, and algorithmic optimization. In addition, the processing ability is six times larger than our first work. Our proposed architecture is the worldwide first reported JPEG XR single-chip encoder. he second part of this dissertation describes two algorithm designs for scalable video application which is emerging recently. When transmitting video over a heterogeneous network, it is required to satisfy the different constraints due to the preferences and equipment selections of different users. More than one video parameters include spatial frame size, temporal frame rate, and visual quality resolution are utilized to provide better scalability in scalable video application. It is difficult to find the relationship between the various video parameter settings and user preferences. In this part, we propose a multidimensional adaptation selection scheme to match the preferences of the video parameters for each user. This scheme characterizes the relationship between spatial, temporal and SNR scalabilities according to the subjectiveness of each user. An objectivity-derived emulation scheme is used in video adaptor to realize the selection of multidimensional adaptation. Therefore, our proposed video adaptor provides more appropriate adjustments of the video parameters for each user. After objectivity-derived scheme is derived, optimization fitting of proposed model for each user is the next important things. We proposed soft-decision optimization scheme to overcome the uncertainty of the user, which not discussed in presented literatures. Besides, our proposed video adaptor identifies the key frames in sequence to utilize the bandwidth in a more efficient way and achieve better subjective visual quality. The proposed method improves the average accuracy prediction rate from 75% to 94% in overall available adaptation bandwidth of test sequences. The experimental results show that the video adaptor provides high consistence of quality between the adjusted video stream and the expectation of users. Because we analyze the user preference according to the compress-domain data, this scheme can be used in video proxy or gateway without much computation overhead. o satisfy the urgent of providing real-time video service over error prone network in scalable video transmission systems, how to protect the video streaming to have better visual quality is also an important issue. We propose a way to protect the video header information in application layer without modifying standardized syntax. Because we will not modify the syntax of the existed standard and the redundant bits can be embedded in the bitstream, this scheme can be used in combination with any video codecs. Our method can be applied for the environment of video streaming system that we practically used today, since the effort that we made is confined in the application layer. Beside, we also consider channel condition of wireless transmission and propose a way to reduce redundant bits used in channel coding. By doing this, the bitstream can be simply transmitted over practical network such as mobile TV in scalable video streaming application and the reconstructed picture quality outperforms the original one.n brief, we believe that with the technologies proposed in this dissertation can be realized in many real practical systems. We sincerely hope that our research contributions can create a new era for digital multimedia life.
Subjects
Scalable Video Coding(SVC)
APEC
Type
thesis
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