A picked up image acquisition unit acquires a picked up image obtained by picking up an image of a region including a projection region projected by a projector. A recognition processing unit executes a recognition process of a card included in the picked up image. A projection image generation unit generates a projection image to be projected by the projector on the basis of the card recognized by the recognition processing unit. An instruction detection unit detects an instruction for the card. The recognition processing unit detects an object different from the card and provides detection information of the detected object to the instruction detection unit. The instruction detection unit then detects an instruction for the card from the detection information of the object provided thereto. The projection image generation unit generates a projection image on the basis of the instruction for the card.