Time efficient color fringe projection system for 3D shape and color using optimum 3-frequency Selection

Abstract

We present a novel color fringe projection system to obtain absolute 3D shape and color of objects simultaneously. Optimum 3-frequency interferometry is used to produce time efficient analysis of the projected fringes by encoding three fringe sets of different pitch into the primary colors of a digital light projector and recording the information on a 3-chip color CCD camera. Phase shifting analysis is used to retrieve subwavelength phase information. Absolute phase across the field is calculated using the 3-frequency method independently at each pixel. Concurrent color data is also captured via the RGB channels of the CCD. Thus full-field absolute shape (XYZ) and color (RGB) can be obtained. In this paper we present the basis of the technique and preliminary results having addressed the issue of crosstalk between the color channels.

Ultra High-speed 3-dimensional Profilometry Using a Laser Grating Projection System

“…Since the PM was revolving 10,000 times per minute, the measurement time is found to be as small as 2.572 ms, which is ~10 times shorter than those of the previous research [11,12,20,21].…”

“…The intensity of the green LD is around half of that of the bright line in the laser gratings. By analyzing the color Ultra High-speed 3-dimensional Profilometry Using … -Yoon-Chang Park et al images of the projected patterns, we can obtain the color texture of the object as well as the 3D shape of the object [8,12,20,21]. In this way, the LGP system using the polygon mirror can provide all the functions that the LCD or DMD projection system is having.…”

Full-field 3D shape measurement of specular surfaces by direct phase to depth relationship

“…The absolute phase of each pixel is determined by the optimum three-fringe selection method [14]. Using the calibrated parameters of ∆d and d, the depth data are obtained, as shown in Fig.…”

“…Considering the speed and accuracy, four-step phase-shifting algorithm plus optimum three-fringe number selection method [14] will be used to calculate the wrapped phase data and the absolute phase map value pixel by pixel, respectively.…”

Full-field calibration and compensation of lateral chromatic aberration based on unwrapped phase

“…Moreover, whether it is a human topography measurement system or a machine vision system, cameras are the dispensable devices in these technique, especially color cameras can capture color texture and shape data simultaneously. However, images captured by color camera have the phenomenon of chromatic aberrations (CA) and lead to lower precision because of the intrinsic optical properties of lens itself 5 . CA can be divided into lateral chromatic aberration (LCA) and axial chromatic aberration (ACA).…”