clear_obj — Delete an iconic object from the HALCON database.
clear_obj(Objects : : : )
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 HALCON/C. In all other HALCON language interfaces, clear_obj must not be used because objects are destroyed automatically through appropriate destructors.
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.
For a short description of the iconic objects that are available in HALCON see the introduction of chapter Object.
Regarding the use of local variables in HALCON/C: When exiting a subroutine, the local variables are deleted, but the HALCON database is not updated. To update the database and thus free the memory, you must explicitly clear the local objects from the database before exiting the subroutine.
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.