Lossy Image Compression and Stereo Ranging Quality from Mars Rovers
Abstract
We examine the impact of onboard lossy image compression on the quality of automated ranging results derived on Earth from stereo image pairs acquired from Mars rovers. To assess the quality of stereo ranging results under lossy compression, we acquire stereo image data sets of scenes containing surveyed "ground truth" points. We examine the loss of range estimates and the reduction in ranging accuracy as compressed bit rate decreases. We define an image distortion metric that takes into account the effect of some of the processing steps performed in the automated stereo ranging process. Based on empirical stereo image data, we develop a modification to the ICER image compressor that is designed to optimize this distortion metric rather than mean-square-error distortion. The modification does not increase the complexity of ICER and is shown to improve stereo ranging quality as a function of compressed bit rate on test scenes. The modification does not exploit correlations between left and right images in a stereo pair.
- Publication:
-
Interplanetary Network Progress Report
- Pub Date:
- February 2007
- Bibcode:
- 2007IPNPR.168D...1K