the other side of the picture is quite the opposite.why ther

the other side of the picture is quite the opposite.why there is (the )in front of "opposite"?As far as I know ,opposite is an adjective.And as "quite" is an adverb,it can modify the adjective"opposite" without the determiner "the"But in the article which it extracts from Lesson 11 of New Concept English,the original sentence is "the other side of the picture is quite the opposite."Can anyone explain the usage of this "the" here?the chinese input system on this computer is somehow damaged,so I'm sorry that I have to type english