Electrically addressed spatial light modulators (SLM) are widely used in optical image processors to display not only input images but also a huge variety of optical components such as lenses, complex filters and other diffractive elements. These components are fully programmable and dynamically controllable by computer thus bringing flexibility and new degrees of freedom to current optical and digital image processors. A good characterization is the most important step in the SLM initialization. The quality and effectiveness of the optical component addressed to the SLM strongly depends on the knowledge of the device response. This work deals with the spatial and temporal characterizations of reflective zerotwist liquid-crystal on silicon (LCoS) SLM. The signal is spatially modified before addressing it to the LCoS SLM to compensate for the distortions internally introduced by the device. For time varying optical components, the signal is also modified before addressing it to the LCoS SLM to compensate for the distortions internally introduced by the device when phase variations of 2π are required at high rate. Experimental results and applications in image processing are shown.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.