Delete an iconic object from the HALCON database.
clear_obj deletes iconic objects, which are no longer needed, from the HALCON database. It should be noted that clear_obj is the only way to delete objects from the database, and hence to reclaim their memory, in all host languages except Smalltalk and C++.
Images and regions are normally used by several iconic objects at the same time (uses less memory!). This has the consequence that a region or an image is only deleted if all objects using it have been deleted.
The operator reset_obj_db can be used to reset the system and clear all remaining iconic objects.
Regarding the use of local variables: Because only local variables are deleted on exit of a subroutine (or a rule in Prolog), while the HALCON database is not updated, it is necessary to clear local objects before exiting the subroutine. Special care has to be taken if backtracking is possible in Prolog (before reaching the clear_obj statements).
|
Objects (input_object) |
object(-array) -> object |
| Objects to be deleted. | |
clear_obj returns 2 (H_MSG_TRUE) if all objects are contained in the HALCON database. If not all objects are valid (e.g., already cleared), an exception is raised, which also clears all valid objects. The operator set_check(::'~clear':) can be used to suppress the raising of this exception. If the input is empty the behavior can be set via set_system(::'no_object_result',<Result>:). If necessary, an exception is raised.
clear_obj is reentrant and processed without parallelization.
Basic operators
