ABSTRACT
This chapter describes the basic elements for direct imaging techniques and systems (i.e., systems that do not rely on mathematical reconstruction to form an image). We begin by considering the fundamental characteristics of laser and white light sources, then describe the basic properties and structure of twodimensional image sensors, image intensifiers, and thermal sensors. We explain the properties of materials used to provide optical access to the target, such as glass materials for optics and optical fibers. We also present important current topics in applications of direct imaging, including pressure-sensitive paints and measurement of shear stresses in microelectromechanical systems (MEMS). These techniques are now seeing considerable development and advances. Finally, a brief description of machine vision will survey the future of direct imaging techniques.
