Virtually lossless compression of astrophysical images

作     者：Lastri, C Aiazzi, B Alparone, L Baronti, S 

作者机构：CNR Italian Natl Res Council IFAC Inst Appl Phys Nello Carrara I-50127 Florence Italy Univ Florence DET I-50139 Florence Italy 

出 版 物：《EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING》 (EURASIP信号处理进展杂志)

年 卷 期：2005年第2005卷第15期

页      面：2521-2535页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

主　　题：astrophysical images differential pulse code modulation lossless compression near-lossless compression noise estimation statistical context modeling 

摘      要：We describe an image compression strategy potentially capable of preserving the scientific quality of astrophysical data, simultaneously allowing a consistent bandwidth reduction to be achieved. Unlike strictly lossless techniques, by which moderate compression ratios are attainable, and conventional lossy techniques, in which the mean square error of the decoded data is globally controlled by users, near-lossless methods are capable of locally constraining the maximum absolute error, based on user s requirements. An advanced lossless/near-lossless differential pulse code modulation (DPCM) scheme, recently introduced by the authors and relying on a causal spatial prediction, is adjusted to the specific characteristics of astrophysical image data (high radiometric resolution, generally low noise, etc.). The background noise is preliminarily estimated to drive the quantization stage for high quality, which is the primary concern in most of astrophysical applications. Extensive experimental results of lossless, near-lossless, and lossy compression of astrophysical images acquired by the Hubble space telescope show the advantages of the proposed method compared to standard techniques like JPEG-LS and JPEG2000. Eventually, the rationale of virtually lossless compression, that is, a noise-adjusted lossles/near-lossless compression, is highlighted and found to be in accordance with concepts well established for the astronomers community.