Adaptive imaging system with spatial light modulator for robust shape measurement of partially specular objects

3D shape measurement of discontinuous specular objects based on advanced PMD with bi-telecentric lens.

This paper presents an advanced phase measuring deflectometry (PMD) method based on a novel mathematical model to obtain three dimensional (3D) shape of discontinuous specular object using a bi-telecentric lens. The proposed method uses an LCD screen, a flat beam splitter, a camera with a bi-telecentric lens, and a translating stage. The LCD screen is used to display sinusoidal fringe patterns ...

Full-Field Shape Measurement of Specular Surfaces

Adaptive Representation of Specular Light Flux

Caustics produce beautiful and intriguing illumination patterns. However, their complex behavior make them difficult to simulate accurately in all but the simplest configurations. To capture their appearance, we present an adaptive approach based upon light beams. The coherence between light rays forming a light beam greatly reduces the number of samples required for precise illumination recons...

Flexible Adaptive Phase Contrast Methods Using a Spatial Light Modulator

Imaging biological objects often is a challenge as most of biological specimens are mainly phase objects. This leads to a reduced contrast. To overcome this problem without using dyes, different phase contrast imaging methods were developed. The most established methods in conventional microscopy are the so-called Zernike phase contrast and Nomarski differential interference contrast (DIC) [1]....

Extracting the shape and roughness of specular lobe objects using four light photometric stereo

Two important aspects of part inspection are the measurement of surface shape and surface roughness. We propose a noncontact method of measuring surface shape and surface roughness. The method, which we call “four light photometric stereo”, uses four lights which sequentially iUuminate the object under inspection, and a video camera for taking images of the object. Conceptually, the problem we ...