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RASTER BASED 1/25,000 TOPOGRAPHIC MAP REVISION 
Masanori KOIDE, Izimi KAMIYA, Tomio YOSHINARI, Bokuro URABE, Yoshikazu FUKUSHIMA, Hiromichi MARUYAMA 
TOPOGRAPHIC DEPARTMENT, GEOGRAPHICAL SURVEY INSTITUTE, JAPAN 
Commission IV 
ABSTRACT: 
One to twenty-five thousand scale topographic maps are the largest scale base maps covering the whole 
territory of JAPAN. GEOGRAPHICAL SURVEY INSTITUTE revises them every 5 to 15 years. In order to shorten 
this cycle, and to reduce cost and time for the revision process, introduction of computer technology into 
the revision process of the maps has been studied since 1987 F.Y. 
The new method is mainly based on raster technology. 
The previous maps, the target of the revision, have 
not yet been digitized. Therefore, it is very difficult to apply the vector based editing method to the 
revision process. However, it is not so difficult to obtain raster data of the previous map using dram 
scanner at the time of the revision. Therefore, we intended to develop the method to maintain the raster 
data of the 1/25,000 scale topographic maps as follows. 
First of all, the previos version map is scanned and raster data of the map are obtaind. On the other 
hand, vector data of changed parts are obtained using stereo plotter with coordinate encoders. Then, the 
raster data of the previous map are edited on a EWS referring the vector data of changed parts. 
Finally, 
the edited raster data are directly plotted into film using laser plotter for plate making. 
KEY WORDS: Cartographic, Map Revision, Raster. 
1. INTRODUCTION 
One to twenty-five thousand scale topographic maps 
are the largest scale maps covering the whole 
territoly of JAPAN. To revise these maps is one of 
the main tasks of GEOGRAPHICAL SURVEY INSTITUTE, 
national organization responsible for surveying and 
mapping of JAPAN. However, we have to maintain 
4,411 sheets of maps in the limited budget and 
personnel, so a new revision method to reduce cost 
and time is truly needed. 
In addition, the present revision method include 
the photact process - the special photographic 
process for copying the scribed plate of the 
original map - which is liable to make the quality 
of lines on the scribed plate worse, so the new 
method is required to maintain the quality of the 
original. 
To solve these problem, we have been studying the 
introduction of computer technology into the map 
revision process since 1987 F.Y. One method is to 
digitize the map in the vector form, to overlay the 
changed parts which are obtained using the stereo 
plotter, and to revise the changed parts using CAD 
technology. However, this method takes much cost 
and time for initial vectorization of the maps. On 
the other hand, it is not so difficult to obtain 
raster data of the map using the scanner at the 
time of the revision. Therefore, we have chosen to 
develop the raster based map revision method. The 
development has not been completed, but so far this 
method has been shown to be very promising, so we 
regard this method as the main medium scale map 
revision method of next generation and are trying 
to introduce it in near future. 
2. RASTER BASED 1/25,000 TOPOGRAPHIC 
MAP REVISION METHOD 
2.1 Flow of the Raster Based Revison Method 
Figure 1 shows the flow of the raster based 
1/25,000 topographic map revision method. First of 
all, the previous version map is scanned and raster 
data of the map are obtained. Second, vector data 
of changed parts are obtained using stereo plotter 
with coordinate encorders. Third, the raster data 
of the previous map are revised on a EWS reffering 
the vector data of changed parts. Finally, by 
517 
plotting the revised raster data into films, the 
revised films for reproduction are produced. 
The details of each process are described in the 
following. 
2.2 Scanning and Registration 
  
The 1/25,000 topographic maps are printed in 3 
colors, black, blue, and brown. In the process of 
conventional map production, corresponding to 
colors, line/surface features and annotation, 8 
plates listed on table 1 are produced for each map. 
At this stage in the new method, each plate of the 
previous map is scanned, and the registration 
between plates is performed. Once raster data are 
obtained, this stage is not needed from the next 
revision. 
2.2.1 Scanning Scanning pitch should be small 
from the point of map reproduction after digital 
processing, but should be large from the point of 
efficiency and the number of available scanners. 
From our experience, it is not enough to reproduce 
the map if the scanning pitch is 0.05mm, so the 
experiment of scanning, registration and 
reproduction by proof press was performed to get 
the suitable scanning pitch less than 0.05mm. 
As a result of the experiment, except for 
annotation characters 0.025mm pitch was proved to 
be small enough to get the same quality as the map 
made by the conventional method. Therefore, all 
plates except annotation plate were supposed to be 
scanned in 0.025mm pitch. In this experiment, it 
took about 30 minutes to scan each plate by 
Optronics 4040 scanner. And a plate for scanning 
was produced from each plate in table 1 on a white 
base film in order to avoid the degradation of 
raster data image by the reflection at the back of 
film. 
2.2.2 Registration As scanning is performed for 
each plate for scanning, the registration between 
plates should be done correctly. In the experiment 
we adopted the following method. 
First of all, the registration plate on which 8 
cross lines (hereafter we call them registration 
marks) are scribed at the 4 corners and 4 sides on 
the margin of the map is made. Second, each plate