Using _PACKAGE in pixelclasser-package.R to obtain correct access to the package overview file. Required after changes in roxygen2 behaviour.
The class names of all objects created by functions in pixelclasser
now start with pixel_. The internal structure did not change, however,
so it is safe to change the class of any object created with version 1.0
into the new classes with class(my_object) <- "new_class_name".
Functions is_() and summary() (S3) were added for the
classes created by pixelclasser.
Functions create_rule(), create_subclass() and
create_class() were replaced by pixel_rule(),
pixel_subclass() and pixel_class(), to make the name of the
object constructors equal to the class name.