Astronomical Image Compression Using the Pyramidal Median Transform
Jean‐Luc Starck, Fionn D. Murtagh, Mireille Louys · 1995
. We describe image compression based on the pyramidal median transform, introduced as an alternative to the use of a wavelet transform. The use of a multiresolution support allows "protection" of astronomical objects in the image. Non-support parts of the images are subjected to noise suppression. Experimental applications are presented. 1. Introduction Image compression is required for preview functionality in large image databases (e.g., HST archive), for linking image and catalog information in interactive sky atlases (e.g., Aladin), and for image data transmission, where more global views are communicated to the user, followed by more detail if desired. We describe an approach to astronomical image compression through noise removal. Noise is determined on the basis of the image's assumed stochastic properties. This approach is quite similar to the wavelet transform-based hcompress approach. We begin by explaining why transforms other than the wavelet transform are important for a...