    deferred class
    	EV_GRAPHICAL_FORMAT

    General
    	cluster: interface
    	description: "Base class for graphical formats"

    Ancestors
    	ANY

    Queries
    	color_mode: INTEGER_32
    	file_extension: STRING_32
    	scale_height: INTEGER_32
    	scale_width: INTEGER_32

    Commands
    	set_greyscale
    	set_paletted
    	set_scale_height (a_height: INTEGER_32)
    	set_scale_width (a_width: INTEGER_32)
    	set_truecolor