American Memory:  Technical summary

Other Map Collections

Map 
Collections

URL for collection: http://lcweb2.loc.gov/ammem/gmdhtml/gmdhome.html


Collection Overview

Description
A variety of early maps grouped under themes, including the first delineations of Liberia (1830-1870), a set of maps of the Yellowstone Valley and brand new first National Park, various maps of colonial and revolutionary America, and an 1814 map of Lewis and Clark's track west.
Source collection
n/a
Technical features
High resolution color images of maps; potential for use in GIS systems.
Original material formats
Number of original items
52 (initial release), more to be added month by month
Status of collection
Initial release in March 1998.
Public access
The Library is not aware of any restrictions that inhibit public access to items in this collection. See notes on rights and restrictions provided by the Library to users of this collection.

Aids to intellectual access

Type & granularity
MARC bibliographic records. Each bib. record describes a single item.
Linking to digital reproductions
Bibliographic record contains identifier used in filenames for all versions of image.

Digital reproductions

Total file-space for digital reproductions: 30 Gbytes (estimated)

Maps Archival image Service image Inline thumbnail
Marker Filename extension ".tif" Filename extension ".sid" Filename extension ".gif"
Formats TIFF uncompressed MrSID ( LizardTech
wavelet compression)
GIF
Tonal resolution 24 bit 24 bit 8 bit
Spatial resolution (approx) 300 dpi 300 dpi 200x150 pixels
Quantity (approx) 52 (initial release) 52 (initial release) 52 (initial release)
File size 100-250 Mbytes 3-9 Mbytes 8-15 Kbytes
Sample Sample archival Sample service Sample thumbnail

Library of Congress contribution to Digital Libraries Initiative - Phase II [Site Map]
Collections available: [List] [Rights] [Samples] [Handover]
Technical notes: [Documents] [Images] [Maps] [Sound Recordings] [Motion Pictures]