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The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008
Extracting Spatial object
Digitizing Environnent of Photogrammetric System
4
4
User
Sending Extracted object , , Automatic Correction of
to the OISDBPS system <> 3 ! spatial objects in the digitizing enviroment
Intelligent and automatic
correction of extracted
objects and other related
objects in the database
OISDBPS
4
retrieving related constraints and objects >T> i t sending corrected spatial objects with their
from database automatically non-spatial attributes to the spatial database
automatically and updating existing objects in the database
SDBMS
Figure 1. Process of Correcting spatial data in the developed system
conditions that should be held for the data in the database to be
consistent. Since many of integrity constraints such as semantic
constraints are application-dependent, it is needed to create new
constraints or change the existing constraints with respect to the
application and then store them in the repository again. So in
the system stored rules can be changed or even new rules can be
created by an expert user. For simplifying the definition of the
rules, a user interface window is provided (as illustrated by
figure 2).
[ OISDBPS: Constraints
Il File Database
Constraints Help
|| Object Class
!Road
“T3
opanai uonsuairus
Objectl
Spatial Relstionship
0bject2
[Road
▼ j |Select Relationship... jr| j
[Select Object... _▼]
Constraint ID
Discretion
Create c
ir omit a minimum size Rule
1
—
jadded
Create a new spatial Rule j Omit a rule ¡
Note: You car
i create only new spatial constraints. Non spatial constraints are only created by the build«
Il Existing Spatial and n
on-spatial Constraints for this object:
1 • Road can not be Inside 0 Area Water Feature.
4- Road can not intersect 0 Area Water Feature.
2- Road can not be Inside 0 construction.
3- Road can Intersect 0 construction.
Minimum size of object is followed:
Minimum size of road is 100 m.
View rules :j Help < Exit
Figure 2. User interface window for definition of the rules
After specifying the rules, they are stored in the database. The
stored rules can be enforced on data entry in different problems.
These rules can be used by any user for different problems but
only expert users can change or create new rules. This makes it
possible to use knowledge of experts that is stored in the
database in the form of rules even by a user without this
knowledge. Number of user defined rules for a problem can be
even more than 1032 in this system. The rules are in the form of:
Rule(first object, permission and relationship, second object).
For example:
Rulel for road object class can be like below:
Road ruleJXo.l(Road,not intersect,Construction) Road
can not intersect Construction.
The defined rules are stored in the database of the developed
system and they are automatically applied on data. Figure 3
shows an example of applying consistency constraints on data
simultaneously with digitizing feature from 3D
photogrammetric model.
Figure 3. An example of applying consistency constraints on
data simultaneously with digitizing feature from 3D
photogrammetric model