Fringe-projection profilometry is one of the most commonly used noncontact methods for acquiring the three-dimensional (3D) shape information of objects. In practice, the luminance nonlinearity caused by the gamma effect of a digital projector and a digital camera yields undesired fringe intensity changes, which substantially reduce the measurement accuracy. In this Letter, we present a robust ...

A noncontact, fast, accurate, low-cost, broad-range, full-field, easy-to-implement three-dimensional (3D) shape measurement technique is presented. The technique is based on a generalized fringe projection profilometry setup that allows each system component to be arbitrarily positioned. It employs random phase-shifting, multifrequency projection fringes, ultrafast direct phase unwrapping, and ...

Having combined the advantages of ground-based interferometric radar and Global Position System (GPS), a microwave radar with transponder for three-dimensional displacement monitoring method has been proposed. In this system, the active reflector ensures the long measurement distance at low antenna radiation power; the transponder provides the total solutions to antenna microwave leakage and mu...

Decade-long research efforts toward superfast three-dimensional (3-D) shape measurement leveraging the digital micromirror device (DMD) platforms are summarized. Specifically, we will present the following technologies: (1) high-resolution real-time 3-D shape measurement technology that achieves 30 Hz simultaneous 3-D shape acquisition, reconstruction, and display with more than 300,000 points ...

introduction: estimation of gestational age is an essential component of prenatal care. gestational age is estimated by last menopausal period, fundal height and ultrasonography. serial measurment of fundal height and comparison with lmp predicts the g.a more accurately. since nowadays, ultrasonography is used more frequently during pregnancy, patients have to bear more expenses. but we can use...

This paper presents a high-accuracy 3D (three-dimensional) measurement system using multi-camera passive stereo vision to reconstruct 3D surfaces of free form objects. The proposed system is based on an efficient stereo correspondence technique, which consists of (i) coarse-to-fine correspondence search, and (ii) outlier detection and correction, both employing phase-based image matching. The p...

Shoulder motion is complex and significant research efforts have focused on measuring glenohumeral joint motion. Unfortunately, conventional motion measurement techniques are unable to measure glenohumeral joint kinematics during dynamic shoulder motion to clinically significant levels of accuracy. The purpose of this study was to validate the accuracy of a new model-based tracking technique fo...

Three-dimensional trackers are becoming increasingly important as user inputs in interactive computer systems. These trackers output the three-dimensional position, and often the orientation, of a sensor in space. The three-dimensional tracking is often, however, highly distorted and inaccurate. The purpose of this paper is to discuss methods for the measurement and characterization of the stat...

The determination of uric acid in urine samples was studied by a chemiluminescence measurement using tris (2,2'-bipyridine)ruthenium(II)-octylphenylpolyglycolether [Ru(bpy)3-OPE] system. The oxidized uric acid by Ce(IV) excited Ru(bpy)3 to emit a chemiluminescence in this system so that the intensity was stoichiometrically dependent upon the concentration of uric acid. In a reaction cell, a lum...