LAND USE STATISTICS USING AUTOMATIC SCAN DIGITIZING METHOD
Wen Shimin
National Research Institute of Surveying & Mapping
16 Beitaipinglu, Beijing, China
ABSTRACT
This paper presents the method for doing land use statistics by automatic scan digitizing and its system implemen-
tation. Using this method first needs to scan land use maps from scanners and then do a series of processing such as au-
tomatic and interactive editing, automatic raster to vector conversion, automatic topology, attribute input, attribute
editing and so on. Finally do some statistics on land use and set up land information system. In order to increase the ef-
ficiency of the software system, a series of new algorithms are developed. Using these algorithms can greatly increase
the processing speed and get better results.
KEY WORDS; GIS/LIS, Land Applications, Scanned
INTRODUCTION
As well known as the manual digitizing is a te-
dious, time consuming and costly work, which has low
efficiency and poor accuracy. Therefore in a long period
of time the graphic data capture has been taking for bot-
tle neek of computer information processing and an ob-
stacle to the wide use of CAD and GIS. In order to in-
crease the efficiency of graphic digitizing and realize the
automation of graphic input. We developed a software
package for automaticscan digitizing. The main func-
tions of the software system include data acquisition
from various kinds of scanners, automatic graphic com-
bination, graphic preprocessing, line thinning, interac-
tive graphic editing, raster to vector conversion, vector
data compression, automatic topology, attribute input
and editing, area and arc length calculation, setting
database, updating and inquirying the database and so
on. Besides making statistics on land use ,the automatic
scan digitizing software system can also use to setup
DEM from scanned contour line and to input graphic da-
ta for GIS and engineering CAD. But this paper only
gives us detail introduction about that it is used to do
land use statistics.
HARDWARE CONFIGURATION
At the present this software system has two ver-
sions, one is under UNIX operating system, and the
other is under DOS operating system. Therefore it can
support two kinds of hardware systems, the first one is
based on IBM microcomputer and its compitible comput-
er, and the second is based on workstations such as
SUN, HP, DEC, SGI etc. The scan input device can be
any market available scanners such as HP series,
SHARP series, IS series, HI series, Mecrotek series,
FSS series and so on. Besides the above mentioned
729
scanners,the software system can also support the data
captured by any kind of CCD cameras. The output de-
vices can be plotters and printers. The hardware config-
uration are shown in Fig. 1.
land use
map
input
CCD camera scanner pu
device
SUN IBM
workstation microcomputer
. output
printer plotter tp
device
statistical table land use map
Fig. 1 Hardware configuration
SOFTWARE FUNCTIONS
The land use investigation in china is based on 1:
10,000 land use map to do land use statistics according
to the adminstrative districts, its final results are the
statistical tables of different land uses. The main flow
chart of the land use investigation using this software
system is shown in Fig. 2. From which can discover
that the main functions of the software system are as
follows:
* Data acquisition from scanner
* Graphic combination
