A projection system (1) for projecting an image (71) comprises: a visible light projector (23) that projects the image with visible light; an invisible light projector (30, 33) that projects an invisible light image onto the object with invisible light; an imaging device (43) that captures the invisible light image projected from the invisible light projector; and a controller (5) that obtains information regarding reflected light from the object while obtaining three-dimensional measurements of the object to control the image, based on a capture image. The invisible light image includes a bright region (Rl) and a dark region (R0) having a light amount less than the light amount of the bright region. The invisible light projector emits the invisible light to cause the light amount of the dark region in the invisible light image to be more than or equal to an offset value (b). |