Optical Image Subtraction Using a LCTV SLM and White-light Imaging Grating Interferometer

A new white-light optical image subtraction technique employing a liquid crystal television and a dual-channel achromatic imaging grating interferometer is introduced. A general analysis based on Fresnel diffraction theory for the system with an extended white-light source is made, the condition for the formation of achromatic fringes is derived, and the experimental results are presented. This method is low-cost and easy to perform. It is specially suited for the real-world scene monitoring and can be extended to real-time processing.