Correlation based interpolation technique for accurate 3-D estimation via projection of axially varied patterns

On-axis projection of a-priori known axially varying patterns can be used for three dimensional (3-D) imaging. However, this method can only distinguish between a discrete number of axial planes. In this work, an inter-planar interpolation method is used to estimate the distance by a-priori knowledge about the pattern's compatible axial range. The method is based on the use of three predefined correlation based parameters of the image reflected from the object. The use of several parameters improves the interpolation precision leading to an improved 3-D estimation. An experimental setup was built using a spatial light modulator (SLM) which implements a desired phase element that forms the axially varying projected pattern. The experimental results match the expected behavior foreseen via numerical simulations.[Figure not available: see fulltext.]