A pulsed imaging Raster Output Scanner utilizes pulse width modulation in conjunction with spatial filtering to form three exposure levels at the surface of a recording medium, one of the levels associated with a specific color. In a specific non-facet tracked scanner system, a light beam (84) from a laser source (82) is modulated, by an acousto-optic modulator (92), in accordance with a video signal supplied to the modulator by a control circuit (94). An anamorphic lens system (108) performs a Fourier transform on the modulated beam which is then filtered by a spatial bandpass filter (136) before being directed, by a rotating polygon scanner (142), across the recording medium (162).