| ::count_obj | Number of objects in a tuple. |
| ::get_channel_info | Informations about the components of an image object. |
| ::get_obj_class | Name of the class of an image object. |
| ::get_obj_info | Information about the input image objects last used. |
| ::test_equal_obj | Compare image objects regarding equality. |
| ::test_equal_region | Test whether the regions of two objects are identical. |
| ::test_obj_def | Test whether an object is already deleted. |