The Desaturate submenu contains operations that turn an image into a Grayscale representation, using different methods.
Розділ 8.29, «Color to Gray»
Розділ 8.30, «Desaturate»
Розділ 8.24, «Mono Mixer»
Розділ 8.32, «Sepia»
You can access this command from the main menu through Colors → Desaturate.
