JPL DESCANSO - Deep Space Communications and Navigation Center of Excellence

Image Compression for the Mars Exploration Rovers

Presented by:
Dr. Aaron Kiely
MER Image Compression Developer
Communications Systems and Research Section (331)


The Mars Exploration Rovers Spirit and Opportunity each contain an unprecedented nine cameras on-board, and are transmitting unprecedented volumes of image data from the surface of Mars. How is all of this data being compressed?

This talk will give an overview of the types of images collected by the rovers, explain how on-board image compression works, and describe how it's being used by the MER mission. We'll discuss the methods for controlling the tradeoff between compressed data volume and reconstructed image quality, and how error-containment schemes are incorporated to limit the effects of packet losses on the deep-space communication channel.

The MER mission is significantly advancing the state of practice of image compression for deep-space missions. MER is using discrete wavelet transforms along with state-of-the-art entropy coding and context modeling methods that provide substantially more effective image compression than that obtained by the Mars Pathfinder mission in 1997.

The Speaker

Dr. Aaron Kiely, together with Dr. Matthew Klimesh, developed the ICER image compressor being used by MER. Aaron has been at JPL since 1993 as a member of the Information Processing group in the Communications Systems and Research Section (331), where he has conducted research in data compression and error-correcting codes.