(Email distributed to DS1 members January 25, 1999)

DS1 users,

The procedure to decompress and distribute compressed image data (.eric
files) is complete and has been added to our FEI distribution system.

I'm told only image data taken by the VISCCD or APS detectors are
compressed.  These have been distributed in the FEI fileTypes:
ds1NavPartial, ds1NavComplete, ds1MicasPartial and ds1MicasComplete and are
recognized by the .eric file extension.  Non-compressed image data are
stored in the same fileTypes and are recognized by the .pds file extension.
7/29/99 Addition I received a new version of uneric which
does IR detectors as well.

Image data stored in ds1Partial and ds1Complete are corrupted files and I
have not been able to decompress them.  You should not expect to find valid
image data in those fileTypes.

Files decompressed by our FEI system will be stored in the same fileType as
the compressed file.  The filenames will be the same, except for the file
extension.  Compressed data will retain the extension .eric; their
decompressed counterpart will have an extension of .pds  .  The .mdata file
continues to describe both the compressed and decompressed files so there
is no additional .mdata file for files decompressed by the FEI system.

The procedure works as follows:  

When our FEI server receives any file with a .eric extension it will open
the file and attempt to read the PDS label.  If it is unable to read the
PDS label or if the PDS label is incomplete/corrupt it will close the file
and not attempt to decompress it.  In those cases you will continue to find
only the .eric compressed file in FEI and no .pds decompressed counterpart.
 This could also give you a pretty good indication that there could be
something wrong with the data.  

If the PDS label is complete and the data is not corrupt the file will be
decompressed.  The decompressed file will be named with a .pds extension
and added to the same FEI fileType as the original compressed file.

Users need change nothing (I hope!).  If you have subscriptions for
ds1Nav... and ds1Micas... fileTypes you will continue to receive the .eric
files as you have, and in addition you will now see a .pds file coming over
as well.  Depending on your needs, you may choose to use the compressed or
decompressed data once you get it via FEI.  The scenario is similar for
rushmore users.  The .eric compressed data will be available as it has in
the past; in addition you will find the uncompressed .pds files along with
the compressed data.  You may choose to ftp the compressed, decompressed or
both to your home institution.

None of you use the MIPS Real Time DS1 database, but for the record it should
be noted that NO additional entry will be made in the MIPL RT database for
files decompressed by the FEI system; only an FEI entry for the
decompressed file will be kept in the FEI database.

Please let me know if you have any questions or if this new system might
cause you problems.

Oh, I should note that I had trouble decompressing some of the existing
ds1Nav... and ds1Micas... files.  Following is a copy of my log showing the
files I was unable to decompress. Excluding these exceptions, all data that
could be decompressed has been decompressed and is available now via FEI
and rushmore. An ABEND with no other error message indicates the uneric
software core dumped and the file could not be decompressed although the
PDS label was intact. This makes sense for the partial files, as without a
complete file it may be impossible to decompress it yet - but I'm not sure
why some of the complete files could not be decompressed.

Fri Jan 22 15:16:59 PST 1999
 ABEND - ds1MicasComplete/starcluster8.eric#2 was not decompressed

Fri Jan 22 15:18:50 PST 1999
 ABEND - ds1MicasPartial/starcluster8.eric#1 was not decompressed

Mon Jan 25 13:51:39 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000040_5.eric#3 was not decompressed

Mon Jan 25 13:58:27 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000001_5.eric#1 was not decompressed

Mon Jan 25 13:58:33 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000015_1.eric#1 was not decompressed

Mon Jan 25 13:58:58 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000015_2.eric#1 was not decompressed

Mon Jan 25 13:59:09 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000015_3.eric#1 was not decompressed

Mon Jan 25 13:59:15 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000015_5.eric#1 was not decompressed

Mon Jan 25 13:59:33 PST 1999
 ABEND - ds1NavComplete/nav_image_111_2000020_1.eric#1 was not decompressed

Mon Jan 25 14:31:37 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000004_2.eric#1 was not decompressed

Mon Jan 25 14:32:28 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000004_4.eric#2 PDS label is missing
necessary decompression values, 'uneric' was not performed on this file

Mon Jan 25 14:32:50 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000019_2.eric#1 was not decompressed

Mon Jan 25 14:33:06 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000089_1.eric#1 was not decompressed

Mon Jan 25 14:33:31 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000040_1.eric#1 was not decompressed

Mon Jan 25 14:34:30 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000004_6.eric#1 was not decompressed

Mon Jan 25 14:34:43 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000040_2.eric#2 was not decompressed

Mon Jan 25 14:35:02 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000040_4.eric#2 was not decompressed

Mon Jan 25 14:35:10 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000040_5.eric#2 was not decompressed

Mon Jan 25 14:35:23 PST 1999
 ABEND - ds1NavPartial/nav_image_111_2000015_4.eric#1 was not decompressed

Cheers,
Pam