Jiri Hon on "Why can't hook into wp_ajax_image-editor action?"

Dear WordPress community,
please, does anybody know why the following code does not work? It should output Hello world when loading image editor with AJAX, but does nothing.

function say_hello()
{
	var_dump("Hello world");
}
add_action( 'wp_ajax_image-editor', 'say_hello' );

Is there something I'm missing?

Thank you a lot,
Jiri Hon