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Objective: Accept JPEG2000 as a PDS archive format for Imaging Product RDRs
     Date: 2003-08-20 (submitted), 2004-04-19 (modified)
   Author: Steve Hughes (submitted), Joel Wilf (modified)

Background
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The MRO HiRISE (High Resolution Imaging Science Experiment) team is currently
predicting the production of 12,100 Gb (Giga bits) of EDR products and 92,500
Gb of RDR products. The maximum sizes of the EDR and RDR products are expected
to be about 262MB and 5,120MB respectively. This large volume of data and the
large size of the individual products raises several data management issues
involving data storage and the distribution of products over the internet.

The MRO HiRISE team is suggesting that the JPEG2000 compression scheme be used
to compress the HiRISE products for use in both online data repositories and
for the PDS archive. The JPEG2000 compression scheme provides a good
compression ratio (~1.7:1 lossless) and uses wavelet encoding scheme to allow
easy viewing of extremely large images. The use of the JPEG 2000 compression
scheme will (in the words of the team) result in lower data volume
requirements, smaller storage needs, lower media costs, more easily managed
datasets, lower per-unit count of hard media, and faster transfer times. It
will also preclude the need for product tiling.

Note that the MRO HiRISE team is proposing JPEG2000 for HiRISE RDRs only.

Current Urgency
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The MRO HiRISE team as well as the PDS are currently developing plans that
include hardware and software procurement, operations center design, product
distribution mechanisms, and archive media production. The volume of data and
the size of the individual products are the design variables with the most
impact at this time. The possible use of JPEG2000 directly effects these two
variables.

Since JPEG2000 will most likely be used in the online repository in any case
the decision on whether or not the PDS will allow JPEG2000 in the archive
impacts the proposed interface and must be made as soon as possible.

Recommendations
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The data engineering and technical group recommend the following actions:

  1. The JPEG2000 compression scheme be accepted by the PDS Management
     Council as suitable for RDR Imaging products in the PDS archive.  

  2. That documented references to PDS accepted compression schemes/data
     formats be modified to include the JPEG2000 compression scheme. Note
     that JPEG2000 should be considered both a compression scheme as well
     as a data format.

  3. That work begin on providing an OBJECT definition of JPEG2000 
     images for the Planetary Science Data Dictionary (PSDD), as well 
     as modifications to PDS Standards Reference describing use of the 
     new format. Note that these changes to the data dictionary and
     standards will be proposed under a separate SCR.

  4. That work begin on describing all modifications to PDS software 
     required for PDS to properly validate, access, and view JPEG2000
     products. Note that these modifications will be proposed under a 
     separate SCR.
  
Impact Statement
================
The MRO HiRISE and PDS will begin cooperative effort to create a complete
definition of JPEG2000 HiRISE RDRs, as described above. Changes to the PDS
Standards Reference, Data Dictionary, and PDS software toolkit are pending
the results of this effort.