Bit-Error Aware Quantization for DCT-based Lossy Compression
| Autor: | Jialing Zhang, Jiaxi Chen, Seung Woo Son, Xiaoyan Zhuo, Aekyeung Moon |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Lossless compression
020203 distributed computing Computer science Quantization (signal processing) Mechanism based Data_CODINGANDINFORMATIONTHEORY 010103 numerical & computational mathematics 02 engineering and technology Lossy compression 01 natural sciences Bottleneck Compression ratio 0202 electrical engineering electronic engineering information engineering Discrete cosine transform 0101 mathematics Gas compressor Algorithm |
| Zdroj: | HPEC |
| Popis: | Scientific simulations run by high-performance computing (HPC) systems produce a large amount of data, which causes an extreme I/O bottleneck and a huge storage burden. Applying compression techniques can mitigate such overheads through reducing the data size. Unlike traditional lossless compressions, error-controlled lossy compressions, such as SZ, ZFP, and DCTZ, designed for scientists who demand not only high compression ratios but also a guarantee of certain degree of precision, is coming into prominence. While rate-distortion efficiency of recent lossy compressors, especially the DCT-based one, is promising due to its high-compression encoding, the overall coding architecture is still conservative, necessitating the quantization that strikes a balance between different encoding possibilities and varying rate-distortions. In this paper, we aim to improve the performance of DCT-based compressor, namely DCTZ, by optimizing the quantization model and encoding mechanism. Specifically, we propose a bit-efficient quantizer based on the DCTZ framework, develop a unique ordering mechanism based on the quantization table, and extend the encoding index. We evaluate the performance of our optimized DCTZ in terms of rate-distortion using real-world HPC datasets. Our experimental evaluations demonstrate that, on average, our proposed approach can improve the compression ratio of the original DCTZ by 1.38x. Moreover, combined with the extended encoding mechanism, the optimized DCTZ shows a competitive performance with state-of-the-art lossy compressors, SZ and ZFP. |
| Databáze: | OpenAIRE |
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