ing to its function in the process, into the semantic and. the metric
part. The relevant basic operations are:
Semantic: Scanning, abstraction and conversion.
Combined: Parallax detection, control, recording.
Metric Tracking and metric correspondence.
Operations normally performed by the human are: scanning,
abstraction, conversion, parallax detection and control;
and operations realised by the instrument itself (to be tested) are
tracking, metric correspondence, recording and all the transmis
sions in the instrument (mechanical, optical, electrical).
In more advanced automatic systems, there are additional
instrumental operations: parallax detection, some aspects of con
trol and some related operations (e.g. slope gradient detection
in the contouring mode).
i
fig. 4b
In optical rectifiers the same approach is applicable. However,
in addition to the metric correspondence, the operations belonging
to the flow of semantic information (lens equation condition and
Scheimpflug condition) should also be tested.
For detailed tests, the basic operations should be broken down
into more elementary operations.
3. Classification of tests
For the conducting of tests, it is essentially important to have a
consistent classification of tests according to their various objectives.
The diagram in fig. 5 shows a classification according to five basic
aspects: the stage, purpose, type, means for execution and mode of
operation.
8i
metric information
A
semantic information
A
optical
image
transfer
*1 PRINTING
ILLUMINATION
OF PHOTOGRAPH
METRIC
CORRESPONDENCE
