1. A visible image forming apparatus comprising: a visible image forming unit that forms a visible image in the air; a controller that causes the visible image forming unit to form the visible image representing a print image; an operation detection unit that detects an operation of an operator performed on the print image displayed as the visible image by the visible image forming unit; and a print image processing unit that processes the print image according to the operation detected by the operation detection unit, wherein the controller causes the visible image forming unit to form, in the air, the visible image representing the print image processed by the print image processing unit.