2009

Low-Complexity Lossless and Near-Lossless Data Compression Technique for Multispectral Imagery

The technique allows substantially smaller compressed file sizes when a small amount of distortion can be tolerated.

This work extends the lossless data compression technique described in “Fast Lossless Compression of Multispectral-Image Data,” (NPO- 42517) NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26. The original technique was extended to include a near-lossless compression option, allowing substantially smaller compressed file sizes when a small amount of distortion can be tolerated. Near-lossless compression is obtained by including a quantization step prior to encoding of prediction residuals. The original technique uses lossless predictive compression and is designed for use on multispectral imagery. A lossless predictive data compression algorithm compresses a digitized signal one sample at a time as follows: First, a sample value is predicted from previously encoded samples. The difference between the actual sample value and the prediction is called the prediction residual. The prediction residual is encoded into the compressed file. The decompressor can form the same predicted sample and can decode the prediction residual from the compressed file, and so can reconstruct the original sample.

A lossless predictive compression algorithm can generally be converted to a near-lossless compression algorithm by quantizing the prediction residuals prior to encoding them. In this case, since the reconstructed sample values will not be identical to the original sample values, the encoder must determine the values that will be reconstructed and use these values for predicting later sample values. The technique described here uses this method, starting with the original technique, to allow near-lossless compression.

The extension to allow near-lossless compression adds the ability to achieve much more compression when small amounts of distortion are tolerable, while retaining the low complexity and good overall compression effectiveness of the original algorithm.

This work was done by Hua Xie and Matthew A. Klimesh of Caltech for NASA’s Jet Propulsion Laboratory. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it. . NPO-46625

White Papers

Windows CE Development for RISC Computers Made Easy
Sponsored by Sealevel
Future Advances in Body Electronics
Sponsored by Freescale
Overcoming the Barriers Imposed by Geometry
Sponsored by SpaceClaim
6 Ways Software Rendering Boosts Embedded System Graphics
Sponsored by ENSCO Avionics
What They Didn’t Teach You in Engineering School About Heat Transfer
Sponsored by Mentor Graphics
T&M Solutions for Software Defined Radios (SDR)
Sponsored by Rohde and Schwarz A and D

White Papers Sponsored By: