International Congress on Archives 2004 pres 235 SHAPLEY CIT 01 E Page 7
15
th
International Congress on Archives
Shapley
www.wien2004.ica.org
6
NATIONAL ARCHIVES OF AUSTRALIA IMAGE CAPTURE OUTPUT SPECIFICATIONS AND
STATISTICS
Digital camera
Canon G5
Image size/resolution
1200 x 1600 pixels/72dpi
Image format
Progressive jpeg, compressed
Document size
Width (cm)
Height (cm)
Large 42.33 56.44
Small 25.40 33.87
Pixel dimensions
Width
(pixels)
Height
(pixels)
Large 1,200 1,600
Small 810
960
Average image file sizes
Large 159KB
Small 66KB
Output rate
In ideal conditions, an average of 140 images can be captured and processed per operator per hour.
Approximately 48 minutes per hour are spent on capturing images and 12 minutes on processing by
ImageStore. Breaks are usually taken while processing is occurring. Processing time is also used for
reassembling records that have been taken apart for capturing.
Storage of captured data
The server is a Dell with two 1GHz processors, 1024Mb RAM and 3.5Tb of disk. The disk drives are in
Storage Area Network (SAN) configuration. This allows the addition of extra disk capacity to the current
server, as well as additional servers with their own disks. A tape library is used to back up the server.
Because of the way the application is designed and the database is structured, only 2Gb can be loaded per
day. The current monthly growth rate is 4050Gb. A rolling database design, where the maximum database
size is set at 200Gb, means that new databases are created as required. New records are only written to the
last database created. Full backups of the current database and the control database are done weekly, with
daily incremental backups for all databases and rolling backups for non-current databases.
