Table of Contents for: Section J | Entire RFP




The project described in this section is being carried out by the Geography and Map Division and the National Digital Library Program. The purpose of this project is to digitize approximately 2,000 Civil War maps that have been placed on approximately 3,000 105mm color microfiche. Many of the larger maps have been divided into segments or sections; each segment or section was separately photographed for the fiche. This segmentation explains why the quantity of fiche exceeds the number of maps.

The maps on fiche represent about one-fifth of the Library's total holdings of Civil War maps. The entire corpus, including the maps reproduced on fiche, is described in Richard W. Stephensons's book Civil War Maps: an Annotated List of Maps and Atlases in the Library of Congress (Second Edition. Washington: Library of Congress, 1989. ISBN 0-8444-0598-1, for sale by the Superintendent of Documents, Government Printing Office). This volume describes the original maps and lists the bibliographic entry number (i.e., catalog number) assigned to each map.

The original maps range widely in size: the smaller maps include examples at 10x7 cm (ca. 4x3 inches), larger maps include examples at 116x84 cm (ca. 45x33 inches). Most of the larger maps have been filmed in segments. The precise range of segment sizes in not known; a partial survey suggested that few fiche images represent map segments greater than 100 cm (ca.. 40 inches); many appear to be in the range of 40-70 cm (ca. 15-30 inches).

The Library wishes to create digital archival or "master" images of these maps and map segments. Within the limits of fiche-scanning technology, these archival images are intended to match the quality and scale of the archival files that the Library produced when it scans similar original paper maps directly. These files are generally 300 dpi, 24-bit color uncompressed images at the actual scale or size of the original. For example, a map segment measuring 35x44 cm (ca. 14x17 inches) would be represented in a digital image with a resolution of about 4200x5100 pixels.

After receiving the images from the contractor, Library will archive them in its digital repository and create copies in one or more formats that will provide researchers with online access to the collection.


6.2.1 Film and Condition

The contractor shall create digital images of approximately 3,000 maps or map segments from the Civil War maps on fiche group. Each map or map segment is the sole content of a 105mm fiche. A 105mm fiche measures 4 3/8 x 6 inches. The images of the maps or map segments on the fiche are generally about the same vertical size (roughly 3 to 3.5 inches), with the horizontal dimension falling where it may, but not exceeding about 5 inches.

In addition to the map or map segment, the fiche image includes (1) a six inch ruler and (2) a set of Kodak color control patches. In order to have the map fill the frame (to the degree possible), the fiche were made at varying reduction ratios.

The fiche are on Cibachrome stock and represent the camera original, i.e., the actual stock exposed in the fiche camera. The film was exposed by Library staff and processed by MicroColor International of Midland Park, New Jersey.

6.2.2 Item Identification

Each fiche is marked across the top with an identification that includes:

  • the map title or its equivalent
  • the bibliographic entry (catalog) number of the map
  • indication of segmentation, e.g., 1 of 2, 2 of 3
  • indication of copy number when the Library holds more than one copy, e.g. c.2 for copy 2
  • The information on the fiche will be the basis for assigning the filename to the digital image of the map or map segment.


    6.3.1 Determining Image Pixel Dimensions

    The pixel dimensions of the delivered images shall be the same as the pixel dimensions would have been if the original paper item had been scanned at 300 dpi. The contractor shall determine the proper pixel dimensions by analyzing the ruler pictured on the fiche. After the captured image has been properly scaled, the length of the six inch ruler shall be represented by 1800 pixels (6 inches x 300 dpi = 1800). The pixel dimensions of the delivered images shall not vary from the values calculated for the ruler by more than 5 percent. For example, for a map with a theoretical vertical dimension of 4200 pixels, the actual vertical dimension of the delivered image must fall between the values 3927 (4134 less 5 percent) and 4341 (4134 plus 5 percent). Allowing for this variance, the length of the six-inch ruler shall be represented by not less than 1710 nor more than 1890 pixels.

    The pixel dimensions of the delivered images shall represent the actual optical resolution of the capture device.

    6.3.2 Concatenation of Images

    The original maps and map segments range to the order of 30 inches and thus must be reproduced in digital files that range to the order of 9000 pixels. If the contractor's capture device offers resolution lower than that required, then the contractor shall concatenate a composite image from a series of scans of tiles or segments of the fiche image.

    The concatenated images shall minimize the evidence of the edges where tiles or segments are stitched or joined. The most important factor is the alignment and scaling of the segments; the Library requires that lines or words on the parts of the map image be in alignment. The second factor is matching of shade or tone; the Library requires that RGB values for a single uniform area of the original map that fall into more than one tile or segment (before stitching) be within 5 percent of each other.

    6.3.3 Header Content

    The general requirements for TIFF headers given in Section C.4.3 apply to these images. For clarification, the Library states that the headers for these files shall represent the values for width, length, and resolution that would have been obtained if the entire map or map segment had been captured from paper as a single image. For example, in the case of the first map in the table above, the width would be 5198, the length 4134, the resolution 300, and the resolution unit dpi.

    6.3.4 Cropping and Borders

    The contractor shall include in the delivered image:

  • the entire map or map segment as shown on the fiche

  • the ruler, generally photographed lying to the left of the map
  • the color control patches and gray scale (if any), generally photographed lying to the right of the map
  • These items shall be captured in a capture rectangle that goes beyond the edge of the map, ruler, or color control patches. The capture rectangle shall always be beyond or outside the map, ruler, or color control patches. In effect, the capture rectangle forms a border around the objects; this border shall never be less 20 pixels in width. The color of the capture rectangle/border shall be whatever color is present on the microfiche; that is, there is no requirement to make the rectangle/border precisely the same shade for each digital image.


    The contractor shall assign filenames to the map images based upon the information printed on the top of the fiche. The files shall be in the TIFF format. Since for a portion of their life cycle at the Library, the images will be processed in DOS system computers, the filenames shall be eight characters long, with the extension .tif. Since so few map images will fit on each CD-ROM, there are no requirements for creating named directories.

    The assignment of names by the contractor shall adhere to the following guidelines:
    Char Assigned content Example Fiche mark at top
    1 Bibliographic entry number before the separator point ("decimal point"); if needed, fill before and after with zeros to make five character expression 05330 533
    2 h0810 H81
    3 0520a 520a
    4 s0420 S42
    5 0066b 66b.5
    6 Bibliographic entry number after the separator point ("decimal point"); if needed, fill after with zeros to make two character expression .20 465.2
    7 .22 456.22
    8 Feature code (see below) d 2 of 3

    Feature codes. The eighth character shall consist of a code to represent a feature of the map being scanned. The codes are as follows:
    a [Segment] 1 of 2
    b [Segment] 2 of 2
    c [Segment] 1 of 3
    d [Segment] 2 of 3
    e [Segment] 3 of 3
    f [Segment] 1 of 4
    g [Segment] 2 of 4
    h [Segment] 3 of 4
    i [Segment] 4 of 4
    x Copy 1
    y Copy 2
    z Copy 3
    0 no feature



    Mark on fiche

    66b.5 2 of 2
    274 c. 2
    H268 1 of 2


    In accordance with C.4.3, the following set of images shall be created for each individual fiche in the collection:

    CUA - Cartographic Uncompressed Archival Images


    The workflow and setup for this collection will entail scanning and delivery of ten samples from the collection.

    The scanning, follow-on rework, and return shipments of negatives shall be completed within about 40 weeks. Each batch will consist of about 300 fiche; the entire collection includes 10 batches. At no time will more than 900 fiche be away from the Library; one batch en route, one batch at the contractor, and one batch being returned. Additional information on the movement of materials between the Library and the contractor found in Section F.


    The collection identifier for the Civil War fiche group is cwfgm. This collection identifier shall be used as the first part of the volume name for the delivered CD-ROMs. See Section C.9.2

    Table of Contents for: Section J | Entire RFP