Satellite image compression by concurrent representations of wavelet blocks

Abstract

This paper proposes a complete compression and coding scheme for on-board satellite applications considering the main on-board constraints: low computational power and easy bit rate control. The proposed coding scheme improves the performance of the current Consultative Committee for Space Data Systems (CCSDS) recommendation for a low additional complexity. We consider post-transforms in the wavelet domain, select the best representation for each block of wavelet coefficients, and encode it into an embedded bit stream. After applying a classical wavelet transform of the image, several concurrent representations of blocks of wavelet coefficients are generated. The best representations are then selected according to a ratedistortion criterion. Finally, a specific bit-plane encoder derived from the CCSDS recommendation produces an embedded bit stream ensuring the easy rate control required. In this article, both the post-transforms and This work has been carried out under the financial support of the French space agency CNES (www.cnes.fr) and NOVELTIS company (www.noveltis.fr).X. Delaunay NOVELTIS, Parc technologique du canal, 2 av. de l'Europe, the best representation selection have been adapted to the low complexity constraint, and the CCSDS coder has been modified to compress post-transformed representations.

Compression of Multispectral Images with Comparatively Few Bands Using Posttransform Tucker Decomposition

“…In [29], Delaunay has shown that the Lagrangian approach for selecting the best posttransformed block has two main drawbacks. First, the estimation of the required bit rate for ( ) is computationally intensive and not always accurate.…”

“…In [30], the posttransformed blocked coefficients are encoded by an adaptive arithmetic coding method. In [29], the posttransformed blocked coefficients are encoded by the bitplane encoding (BPE) method. However, the posttransforms destroy the zero-tree structure.…”

An Efficient Image Compressor for Charge Coupled Devices Camera

“…In [53], the bit-plane encoder (BPE) is used to encode both the posttransformed blocked coefficients and the side information. However, the posttransforms destroy the zero-tree structure; the PSNR using BPE is 0.2 dB less than using DWT and even worse at high bit rates.…”

“…In [ 53 ], Delaunay et al have shown that the Lagrangian approach to select the best posttransformed block has two main drawbacks: (1) the bit rate estimation of encoding R ( f q b ) is computationally intensive and not always accurate; (2) the choice of the best posttransformed block depends on the quantization step q in the rate-distortion criterion. However, the coder does not define the quantization step when coding.…”

“…In [ 54 ], an adaptive arithmetic coder is used to encode both the posttransformed blocked coefficients and the side information of the chosen posttransform bases on each block. In [ 53 ], the bit-plane encoder (BPE) is used to encode both the posttransformed blocked coefficients and the side information. However, the posttransforms destroy the zero-tree structure; the PSNR using BPE is 0.2 dB less than using DWT and even worse at high bit rates.…”