The invention relates to compounds that are useful as immunosuppressive agents and for treating and preventing inflammatory conditions, allergic disorders, and immune disorders.

Vinyl-phenyl derivatives for inflammation and immune-related uses

JPEG2000 is a recently standardized image compression algorithm. The heart of this algorithm is the coding scheme known as embedded block coding with optimal truncation (EBCOT). This contributes the majority of processing time to the compression algorithm. The EBCOT scheme consists of a bit-plane coder coupled to a MQ arithmetic coder. Recent bit-plane coder architectures are capable of producing symbols at a higher rate than the existing MQ arithmetic coders can absorb. Thus, there is a requirement for a high throughput MQ arithmetic coder. We examine the existing MQ arithmetic coder architectures and develop novel techniques capable of absorbing the high symbol rate from high performance bit-plane coders, as well as providing flexible design choices

Concurrency techniques for arithmetic coding in JPEG2000

In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which is based on a polynomial model. To achieve better coding efficiency, the motion estimation scheme used in H.264 is different from previous coding standards. In H.264, a 16/spl times/16 macroblock can be divided into different block shapes for motion estimation. Each macroblock contains more motion vectors than previous coding standards. For nature video, the blocks within a small area likely belong to the same object, hence the motion vectors of neighboring blocks are highly correlated. Based on the correlation of neighboring motion vectors, we can use the motion vectors that are adjacent to the lost motion vectors to constitute a polynomial model, which can describe the change tendency of motion vectors within a small area. Through this model, the lost motion vectors can be predicted and the lost macroblocks can be reconstructed. Different video sequences are used to test the performance of proposed method. The simulation results show that the quality of corrupted video can be obviously improved by proposed algorithm.

Efficient motion vector recovery algorithm for H.264 based on a polynomial model

This work presents a parallel context-modeling coding architecture and a matching arithmetic coder (MQ coder) for the embedded block coding (EBCOT) unit of the JPEG2000 encoder. The tier-1 of the EBCOT consumes most of the computation time in a JPEG2000 encoding system, and the proposed parallel architecture can increase the throughput rate of the context-modeling. To match the high throughput rate of the parallel context-modeling architecture, and efficient pipelined architecture for context-based adaptive arithmetic encoder is proposed. This encoder of JPEG2000 can work at 185MHz to encode one symbol each cycle. Compared with the conventional context-modeling architecture, our parallel architecture can decrease the execution time about 25%.

High-speed EBCOT with dual context-modeling coding architecture for JPEG2000

Increasing the throughput of the JPEG2000 block coder requires bit-plane and arithmetic coders capable of concurrent symbol processing. Previously described pipelined MQ coders are capable of consuming 1 symbol or less per clock cycle. We develop a new pipelined MQ coder that can process exactly two symbols per clock cycle. The technique is implemented on a FPGA, and is compared with our "Hypothesis Testing" arithmetic coder and a reference one symbol per cycle coder. Our implementation gives an increase in throughput of 1.9 times, at the cost of 1.7 times as much hardware, when compared to the reference coder. It also has 1.2 times the throughput, while consuming only 70% of the hardware associated with the Hypothesis Testing coder.

Improved throughput arithmetic coder for JPEG2000

For next generation image compression standard, context-based arithmetic coding is adopted for improving the compression rate. An efficient and high throughput codec design is strongly required for handling high-resolution images. We propose an efficient codec architecture for context-based adaptive arithmetic coding, which exhibits low cost, low latency, and high throughput rate. In addition, it can be programmed for supporting multiple standards such as JPEG, JPEG2000, JBIG, and JBIG2 standards. It exploits three-pipeline stages architecture. Based on parallel leading zeros detection and bit-stuffing handling, symbols can be encoded and decoded within one cycle. Therefore, the throughput rate can be increased as high as the codec operating clock rate. For 0.35 /spl mu/ 1P4M CMOS technology, both the encoding and decoding rate can run up to 185 M symbol/sec. The AC codec only costs 12 K gate count and 860 /spl mu/m/spl times/860 /spl mu/m layout area. These performances can meet high-resolution real time application requirements.

A high throughput low cost context-based adaptive arithmetic codec for multiple standards

In JPEG2000 image compression standard, context-based arithmetic coding is adopted for improving compression rate. Efficient and high throughput codec design is required for handling high-resolution images. We propose an efficient architecture for context-based adaptive arithmetic coding, which can achieve high throughput performance. Based on parallel leading zeros detection and bit-stuffing handling, a symbol can be encoded and decoded within one cycle. Therefore, throughput rate can be increased as high as codec operating frequency. The modified encoding and decoding flows are compatible with JPEG2000 standard. For 0.35/spl mu/m IP4M CMOS technology, encoding and decoding rate can run up to 200 M symbol/sec and 175 M symbol/sec respectively. They only cost 6.8 K and 9.8 K gate count. These high throughput performances can meet high-resolution real time application requirement.

A high throughput context-based adaptive arithmetic codec for JPEG2000

The fields of multimedia and wireless communications have grown rapidly, leading to a great demand for an image coding scheme that has both compression and error-resilient capabilities. Because bandwidth is a valuable and limited resource, the compression technique is applied to wireless multimedia communication. However, strong data dependency will be created while the bit-rate reduction is achieved. Transmission errors always results in significant quality degradation. An error-resilient image coding for discrete cosine transform-based image compression is proposed. It can successfully prevent errors from propagating across image block boundaries with little overhead. Additionally, a novel post-processing error concealment scheme is presented to retain low-frequency information and discard suspicious high-frequency information. Low-resolution information, rather than total corruption, can be obtained during the image-decoding process. Because of low complexity and latency properties, it is very suitable for wireless mobile applications. Simulation results show that good image quality (PSNR=31.78dB) and a low fraction of corruptive blocks (less than 5%) can be achieved even when the bit error rate is 0.1%.

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Error-resilient image coding (ERIC) with smart-IDCT error concealment technique for wireless multimedia transmission

A delay control circuit includes a first delay unit, a signal regulation unit, a selector and a second delay unit. The first delay unit is used for delaying an input signal and generates a delayed input signal. The signal regulation unit is coupled to the first delay unit and outputs a rising edge delay signal and a falling edge delay signal according to the input signal and the delayed input signal. The selector is coupled with the signal regulation unit and outputs one of rising edge delay signal and falling edge delay signal according to the control signal. The second delay unit is coupled to the selector for delaying the output of the selector and outputting an output signal.

Keng-Khai Ong

Papers

A high throughput low cost context-based adaptive arithmetic codec for multiple standards

A high throughput context-based adaptive arithmetic codec for JPEG2000

Error-resilient image coding (ERIC) with smart-IDCT error concealment technique for wireless multimedia transmission

Delay control circuit