Optical shape measurement technology: past, present and future

The paper provides an overview of some of the main competing optical technologies on which future commercial wholefield shape measurement systems are likely to be based. The methods range from those based on pointwise techniques, such as laser triangulation and laser radar, to wholefield techniques such as projected fringes, Gray code methods and white light interferometry. Data analysis procedures including phase shifting and phase unwrapping are also described. The main error sources limiting the performance of the techniques are presented, and their current and prospective performances are assessed in view of recent developments in components such as computers, solid state cameras, and semiconductor lasers.