7. Mindow-oriented types of information
The following types of information have been introduced
to administrate windows and annotate window-oriented:
WHDR Window header
WVT Vertex table
WST Sub-window table
WH History of analysis
WS Statistical results
WPT-SI Properties
Once a window has been set up, a WHDR-records of about
0.5 K bytes and a WH-record do exist while records of the
remaining types of information may be created by
succeeding analysis procedures.
The function of WHDR-records is closely related to that
of HDR-records though access to WHDR-records is not
direct but depends on the way of referencing a window
(cf. section 6). As many different WHDR-buffers have to
be allocated, maintained and supplied by a program
referencing PODIUM as there are different windows to be
simultaneously worked.
If the shape of a window is known this information may be
optionally stored using WVT-records. The name vertex
table associates the table containing a list of polygon
vertices. This is not the case since such a list were too
much influenced by analogous thinking and hence un-
wieldly upon digital data management. Actually the
structure of PODIUM's vertex tables corresponds to that
of the so-called output tables (OT) discussed in /5/.
The property tables provide a means of annotating window-
oriented with respect to an image oriented table, called
property definition table (PDT) and appertaining to ISO
information (cf. section 5). The PDT completely lists
the user defined properties for look up purposes and
classifies them by subjects. Each individual window has
its own property table which for each subject refers to
at most one user selected property. This concept allows
inquiring for the set of all windows
- having one or any number of properties in common
- or even having properties in common which are
characterized by one or any number of subject sub-
groups.