6 - 
• Extracting symbols or lines from toned background (for an example, see Fig. 9), 
and intensifying symbols and lines (see Fig. 10A). 
• Adding shaded relief or tones to a map or chart (see Fig. 10B). 
Some examples of experimental outputs that have been obtained with this equipment 
are: 
• A reduced chart section (Fig. 11B) from a chart section (Fig. 11A). 
• A set of symbols extracted from the chart background (Fig. 9). 
• A computer-generated grid and density wedge printout (Fig. 10B). 
• A printout of scanned block lettering (Fig. 10A). 
Line tracings on translucent mylar overlay have also been scanned experimentally by 
this equipment. These overlays were traced in ink from a 9-by-9-inch map manu 
script. Cadastral, cultural, other line data and photographic interpretation symbols 
can be drawn and logically identified by adjacent vertical lines which are seen by the 
System as a binary code. These marks can be digitized and stored for identification 
like the symbols in Fig. 9. 
Additional programming of several consolidated cartographic operations is required 
before effective use of this new digital technique can be made. However, we envisage 
an early capability to do some of the cartographic operations being performed today 
by manual means based on this experimental work. 
With most forms of mapping or cartographic line data stored in digital form, the 
specified output form for various types of line overlays can be printed. For fastest 
output, but good line quality, symbol line data can also be converted to card form as 
a vector (x + A x, y + A y), and plotted on a standard digital graphic plotting system 
(Fig. 12). Line and symbol positioning accuracies approach 0.01 inch standard error. 
(Fig. 13 is an example of the results that can be obtained.) 
The experimental IBM drum scanner/printer can print lines and stored symbols in 
a matrix of spots, in black, white, or shades of gray (i.e., tints), or as ’’screened” 
photographic copy at a position and spot size precision better than 2 mils. It is 
possible to produce, through appropriate color filters, color overlays directly onto 
color-sensitive film. Economical implementation of such digital techniques in mapping 
and charting operations will take careful planning and major programming efforts. 
The present experimental drum scanner scans or prints at a rate of one revolution 
per second. This speed needs to be increased by a factor of about 10, which would 
allow a 9-by-18-inch photograph to be scanned or printed in 30 minutes. When 
printing out 1 - mil lines, this print-out can then be photographically enlarged six 
times to a useful size of up to 54-by- 108-inches, with 6-mil lines. This is acceptable 
line quality for many charting applications. 
In any digital process, the final printout of a map or chart separation negative will 
probably still need some field or office editing and field checking. In addition, for 
maximum lithographic-quality map or chart production, the ’’print transparencies” 
from the drum printer can be enlarged onto photo-sensitized material, such as K & 
E photosensitive ’’scribcoat”, where any desired additional editing and line scribing 
can then be performed.