Download MrSID Viewer
Windows 95, 98, NT, 2000, XP
Macintosh OS 9.x (latest version available)
Macintosh OS X Plug-ins
- For more information, visit the LizardTech download site.
To download and view maps offline you need a special viewer. Maps are stored in MrSID format. The Library provides access to the MrSID viewer developed by LizardTech. The company has discontinued this viewer and no longer offers support on the product. The Library is providing access to this viewer until a suitable replacement is available. The Library of Congress does not provide help or support for the MrSID viewer.
Download, View, and Print Maps with the MrSID Viewer
To download and view digital images in SID format:
- Download a standalone viewer from the Library of Congress (available above).
- Click on the "Download MrSID image" link at the bottom of the display page.
- Follow the instructions on your PC for saving the file.
- Use the standalone viewer to open the file.
Convert your American Memory images from SID format to TIFF format
(We caution you to examine the file size; many maps are very large and could overwhelm your computer's memory.):
- Open the image in the MrSID viewer (File-Open).
- Choose File, then Export. (or click the small TIFF button.)
- In the box that appears,
- Click "Export to" and check the location in the "Save in" box. If necessary, change the destination folder.
- Click the "1-1" button.
- Click the "full dataset" button.
- Click "Save."
- Click "Go."
View Map at Original Dimensions
For some, American Memory maps appear to be 72 DPI when you open them in PhotoShop (or other graphics software) with overall dimensions more than three times the original map size. Here are the steps to change it back to 300 and the original dimensions.
- Note the total number of pixels in the horizontal and vertical dimensions.
- Change the resolution from "72" to "300," dots per inch (DPI).
- The horizontal and vertical pixel dimensions will automatically change when you change the DPI. Change them back to the original values, manually.
- Click "resample image" with "bicubic" selected. If option 4 is not presented by your software, change the pixel dimensions back to the original values, manually.
- Click OK.
- Verify the change: change "inches" to "centimeters" in the image dimensions and compare to the original dimensions mentioned on the American Memory item record. They should be close, and if they are off slightly, it is probably because the cataloger who measured the map measured to the edge of the map and the scanner scanned to the edge of the paper, or vice-versa.
- Adjust the size, if necessary.
You may print the map in pieces and paste them together. (Printing over-lapping sections helps with piecing.) Or you may take the TIFF file to a local print shop, architecture firm, or any other organization that has access to large format printing equipment.
You may also purchase .tiff files for any items on the Library of Congress Web site in the MrSid format ($20.00 per file, plus shipping) directly from the Library's Photoduplication Service. These are from the original scans prior to their MrSID compression. The Geography and Map Reading Room provides more information.