The impact of JPEG2000 lossy compression on the scientific quality of radio astronomy imagery

TL;DR

This paper evaluates how JPEG2000 lossy compression affects the scientific quality of radio astronomy images, highlighting its potential for denoising at high compression rates but also its impact on source parameter accuracy.

Contribution

It provides a quantitative analysis of JPEG2000's effects on radio astronomy data quality and source detection performance, which was previously not well understood.

Findings

JPEG2000 can denoise images at high compression rates.

High compression reduces accuracy of source parameterisation.

Compression effects vary with compression rate.

Abstract

The sheer volume of data anticipated to be captured by future radio telescopes, such as, The Square Kilometer Array (SKA) and its precursors present new data challenges, including the cost and technical feasibility of data transport and storage. Image and data compression are going to be important techniques to reduce the data size. We provide a quantitative analysis of the effects of JPEG2000's lossy wavelet image compression algorithm on the quality of the radio astronomy imagery data. This analysis is completed by evaluating the completeness, soundness and source parameterisation of the Duchamp source finder using compressed data. Here we found the JPEG2000 image compression has the potential to denoise image cubes, however this effect is only significant at high compression rates where the accuracy of source parameterisation is decreased.