Selector machine comprising an optical detection system provided with an emitter device and with an optical sensor adapted to detect a product to be selected. The emitter device comprises three IR sources, each of which emits electromagnetic radiations in a corresponding spectral band in the infrared spectrum. An electronic control unit alternately turns on the IR sources in corresponding separate time intervals, and the optical sensor detects, in each time interval, corresponding reflected radiations coming from the product. In addition, the electronic control unit comprises a processing module, which is provided with three chromatic channels of a RGB color space in order to associate the measurement signals corresponding to each IR source with a corresponding chromatic channel so as to compose a false color synthesis image of the product.