Problem: Compressed images display as being uncompressed
** Fixed at ArcGIS 8.2 **
Images imported into an ArcSDE Geodatabase using the sderaster command or the ArcGIS GUI tool display as not being compressed in ArcGIS Desktop.
This is a known issue. The ArcGIS GUI does not list ArcSDE raster images as compressed if images are compressed using the LZ77 compression format.
Solution or Workaround
Use the 'sderaster -o list' command at the sde command prompt to verify whether or not the raster data is compressed.