天文图象数据无失真实时数据压缩方法

A Real-Time Data-Compression Method for Astronomical Image Processing without Information Loss

本文介绍一种用于天文观测图象数据无信息丢失的现场实时数据压缩方法。在对原始图象数据可压缩性统计分析之后，介绍了一种适合天文观测数据现场实时数据压缩的方法＂基础比特＋溢出比特＂编码方法。讨论了为提高压缩比而采取的各种措施。以ＤＥＮＩＳ项目中现场观测原始数据压缩为例，说明了信息保存型实时数据压缩的实现过程，最后给出了该方法的实验结果，实验表明，本文介绍的数据压缩方法在无任何信息丢失的情况下，可获得接近理论值的数据压缩比。

real-time lossless data-compression method for astronomical images is discussed. After statistically analysing the probability of compressing the raw images,we describe a real-time data compression method called 'Base-bit plus Overflow-bit' coding which is suitable to compress astronomical images on-site and in which some arrangements have been taken for increasing the compression ratio. A lossless datacompression for DENIS project on-site is taken as an example to show the process of the realization of a real-time lossless data-compression for astronomical images.The experimental results show that by using the data-compression method described in this paper a lossless data compression with a compression ratio close to the theoretical maximum value can be achieved.