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A higher precise inner crack three-dimenssional(3D) reconstructed method of rock specimens is presented. Two inner shapes of the crack are measured with Phase Measuring Profilometry (PMP), and their edges are drawn out by height information instead of the traditional method based on gray information. Subsequently contour matching and height matching are carried out with algorithms due to maximum correlativity. The inner width and volume of the crack are educed according to the fissure of a rock specimen's outer surface, and the 3D profile of the crack is reconstructed with a high repetitive precision superior to 20μm. The proposed method is effective for evaluating the crack's width of rock specimens in the exploitation of petroleum and natural gas with a mechanical analysis method. The experiment shows its feasibility and practicability.

The size and shape of ventricle are very important to analyze and diagnose pathology of human heart. So it is very necessary to measure the profile of ventricle. It is very difficult to measure the ventricle by vivisectional method for its unique function of heart, so the ventricle specimen is adopted to be measured. Three-dimensional (3D) automatic measurement methods are widely used in many fields. In Biology and Medicine society, it can be applicable for surgery, orthopedics, viscera disease analysis and diagnosis etc. Here a new method to measure the 3D surface of ventricle specimen is proposed. Although the traditional 3D measuing method with equal or stated phase-shifting step length possess excellent accuracy, they are much dependent on the consistency of these phase-shifting step lengths. In fact, this condition is very difficult to guarantee. which may lead to the incorrect wrapped phase and incorrect phase unwrapping in some regions, even the reconstructed object may be misshapen or anamorphic. In the proposed method, a novel improved three undecided step lengths phase-shifting algorithm with three unequal phase-shifting steps has been presented detailed and is applied to measure the profile of ventricle sucssesfully. Experiments show that the improved algorithm can not only effectively improve the measuring accuracy, but also branch out its application.

A broad suite of new measurement methods and indicators based on molecular measurement technology have been developed to assess beach water quality, but they have generally been subjected to limited testing outside of the laboratory in which they were developed. Here we evaluated 29 assays targeting a variety of bacterial, viral, and chemical analytes by providing the method developers with twelve blind samples consisting of samples spiked with known concentration of sewage or gull guano and negative controls. Each method was evaluated with respect to its ability to detect the target organism, absence of signal in the negative controls and repeatability among replicates. Only six of the 30 methods detected their targets in at least 75% of the samples while consistently determining the absence of the target in the negative controls. Among quantitative methods, QPCR for Bacteroides thetaiotamicron and Enterococcus detected by Luminex reliably identified all but one sample containing human fecal material and produced no false positive results. Among non-quantitative methods, the Enterococcus esp gene, the Bacteroidales human specific marker and culture-based coliphage were the most reliable for identifying human fecal material. We also found that investigator-specific variations of methods targeting the same organism often produced different results.

Optical metrology for elements with large dynamic range is very important, especially in aspheric components testing field. Cyclic radial shearing interferometer(CRSI) with a small radial shearing ratio of the expanded wavefront's radii to the contracted version's radii can obtain a small magnitude optical path difference(OPD) because the expanded wavefront and its contracted version nearly have the same shape and magnitude, especially for an optical component to be tested with rotationally symmetric surface. The number of fringe pattern can be decreased dramatically and recorded by CCD. This paper demonstrates the feasibility that CRSI could be used to measure an aspheric surface with large dynamic range and large aperture.

Denitrifying microbial communities and denitrification in salt marsh sediments may be affected by many factors, including environmental conditions, nutrient availability, and levels of pollutants. The objective of this study was to examine how microbial community composition and denitrification enzyme activities (DEA) at a California salt marsh with high nutrient loading vary with such factors. Sediments were sampled from three elevations, each with different inundation and vegetation patterns, across 12 stations representing various salinity and nutrient conditions. Analyses included determination of cell abundance, total and denitrifier community compositions (by terminal restriction fragment length polymorphism), DEA, nutrients, and eluted metals. Total bacterial (16S rRNA) and denitrifier ( nirS ) community compositions and DEA were analyzed for their relationships to environmental variables and metal concentrations via multivariate direct gradient and regression analyses, respectively. Community composition and DEA were highly variable within the dynamic salt marsh system, but each was strongly affected by elevation (i.e., degree of inundation) and carbon content as well as by selected metals. Carbon content was highly related to elevation, and the relationships between DEA and carbon content were found to be elevation specific when evaluated across the entire marsh. There were also lateral gradients in the marsh, as evidenced by an even stronger association between community composition and elevation for a marsh subsystem. Lastly, though correlated with similar environmental factors and selected metals, denitrifier community composition and function appeared uncoupled in the marsh.

In phase measuring profilometry (PMP), the object must be static for point-to-point reconstruction with the captured deformed patterns. While the object is rectilinearly moving online, the size and pixel position differences of the object in different captured deformed patterns do not meet the point-to-point requirement. We propose an online PMP based on image correction to measure the three-dimensional shape of the rectilinear moving object. In the proposed method, the deformed patterns captured by a charge-coupled diode camera are reprojected from the oblique view to an aerial view first and then translated based on the feature points of the object. This method makes the object appear stationary in the deformed patterns. Experimental results show the feasibility and efficiency of the proposed method.

Red blood cell (RBC) counting is a standard medical test that can help diagnose various conditions and diseases. Manual counting of blood cells is highly tedious and time consuming. However, new methods for counting blood cells are customary employing both electronic and computer-assisted techniques. Image segmentation is a classical task in most image processing applications which can be used to count blood cells in a microscopic image. In this research work, an approach for erythrocytes counting is proposed. We employed a classification before counting and a new segmentation idea was implemented on the complex overlapping clusters in a microscopic smear image. Experimental results show that the proposed method is of higher counting accuracy and it performs much better than most counting algorithms existed in the situation of three or more RBCs overlapping complexly into a group. The average total erythrocytes counting accuracy of the proposed method reaches 92.9%.

An improved "three steps" mountain-climb searching (MCS) algorithm is proposed which is applied to auto-focusing for microscopic imaging accurately and efficiently. By analyzing the performance of several evaluation functions, the variance function and the Brenner function are synthesized as a new evaluation function. In the first step, a self-adaptive step length which is much dependent on the reciprocal of the evaluation function value at the beginning position of climbing is used for approaching the halfway up the mountain roughly. Secondly, a fixed moderate step length is applied for approaching the mountaintop of the variance function as closer as possible. Finally, a fine step is employed for reaching the exact mountaintop of the Brenner function. The microscope auto-focusing experiments based on the proposed algorithm for blood smear detection have been carried out comprehensively. The results show that the improved algorithm can not only guarantee the precision to get clear focal images, but also improve the auto-focusing efficiency.

The Pacific Estuarine Ecosystem Indicators Research Consortium seeks to develop bioindicators of toxicant-induced stress and bioavailability for wetland biota. Within this framework, the effects of environmental and pollutant variables on microbial communities were studied at different spatial scales over a 2-year period. Six salt marshes along the California coastline were characterized using phospholipid fatty acid (PLFA) analysis and terminal restriction fragment length polymorphism (TRFLP) analysis. Additionally, 27 metals, six currently used pesticides, total polychlorinated biphenyls and polycyclic aromatic hydrocarbons, chlordanes, nonachlors, dichlorodiphenyldichloroethane, and dichlorodiphenyldichloroethylene were analyzed. Sampling was performed over large (between salt marshes), medium (stations within a marsh), and small (different channel depths) spatial scales. Regression and ordination analysis suggested that the spatial variation in microbial communities exceeded the variation attributable to pollutants. PLFA analysis and TRFLP canonical correspondence analysis (CCA) explained 74 and 43% of the variation, respectively, and both methods attributed 34% of the variation to tidal cycles, marsh, year, and latitude. After accounting for spatial variation using partial CCA, we found that metals had a greater effect on microbial community composition than organic pollutants had. Organic carbon and nitrogen contents were positively correlated with PLFA biomass, whereas total metal concentrations were positively correlated with biomass and diversity. Higher concentrations of heavy metals were negatively correlated with branched PLFAs and positively correlated with methyl- and cyclo-substituted PLFAs. The strong relationships observed between pollutant concentrations and some of the microbial indicators indicated the potential for using microbial community analyses in assessments of the ecosystem health of salt marshes.

We propose an improved FTP based on bi-color grating projecting. Two individual sinusoidal fringe patterns with π phase difference can be decoded from the deformed bi-color sinusoidal fringe pattern captured by color digital camera. Accessing the two fringe patterns, we can not only eliminate zero order spectra but also automatically build a binary mask at the same time to mark the valid measurement area easily, by which unwrapping phase time is shorten as well as phase error from invalid area is not transferred into valid area; Furthermore, we can easily expand the captured non-full-field deformed fringe pattern to form full field fringe pattern to guarantee frequency resolution.

Digital micro-mirror device(DMD) is a new type of component which integrates with micro-electronics, micro-machinery and micro-optics. It used as a new type of spatial-light modulator will have a wide prospect in optical information processing and structured illumination three-dimensional sensing. The basic principles of DMD and digital light processor(DLP) have been particularly introduced. The spatio-temporal characteristic of DMD has been extensively studied. The effect on the Phase Measuring Profilometry due to the Spatio-temporal characteristic of DMD is discussed by computer simulation. Experiments have approved the validity of the simulation results which can give the guidance for the application of DMD in structured illumination three-dimensional sensing.

In this paper we proposed a method for three-dimensional (3D) shape measurement and visualization of balloon hull during quick deflation based on Fourier transform profilometry (FTP). A sequence of dynamic deformed fringe images can be grabbed by high-speed CCD camera and saved on disk rapidly. By Fourier transform, filtering, inverse Fourier transform and unwrapping these phase maps in 3D phase space, we can obtain the shape of the rapid deflating balloon in different times. Based on the phase difference between two neighborhood frames, we propound a 3D phase unwrapping algorithm, which will be of great benefit to 3D phase unwrapping in speed and accuracy. The results of our experiment indicate that the method, presented in this paper, can efficiently deal with the surface shape measurement for rapid motion object and will be a promising one with the development of high-speed frame grabber.

A stroboscopic structured illumination system, which can be used in measurement for 3D shape and deformation of high-speed motion object, is proposed and verified by experiments. The system, present in this paper, can automatically detect the position of high-speed moving object and synchronously control the flash of LED to project a structured optical field onto surface of motion object and the shoot of imaging system to acquire an image of deformed fringe pattern, also can create a signal, set artificially through software, to synchronously control the LED and imaging system to do their job. We experiment on a civil electric fan, successful acquire a serial of instantaneous, sharp and clear images of rotation blade and reconstruct its 3D shapes in difference revolutions.

Optical non-contact 3-D shape measurement provides a novel and useful tool for analysis of facial shape and movement in presurgical and postsurgical regular check. In this article we present a system, which allows a precise 3-D visualization of the patient's facial before and after craniofacial surgery. We discussed, in this paper, the real time 3-D image capture, processing and the 3-D phase unwrapping method to recover complex shape deformation when the movement of the mouth. The result of real-time measurement for facial shape and movement will be helpful for the more ideal effect in plastic surgery.

We introduce short-time Fourier transform into Fourier transform profilometry(FTP) to extract zero frequency component included in deformed fringe pattern. This method can be used to eliminate zero component by only one deformed fringe pattern instead of two. First we extract zero component of deformed fringe image using short-time Fourier transform and normalize it, then calculate the normalized Fourier spectra of deformed fringe image, finally subtract the zero component from Fourier spectra Fourier spectra of deformed fringe image. We give the theory analysis. Experimental results verify that this method can eliminate zero component and extend the measuring range of Fourier transform profilometry to nearly three times of that of the traditional FTP using a frame deformed fringe image. So it is an efficient method to extend measuring range and keep measuring speed, and the setup is very simple because of no phase shifting device needed.

Fourier transform profilometry (FTP) based on fringe projection has high speed and high procession advantages, so it is widely used in industrial inspection, solid modeling, biomedicine, machine vision and so on. In this paper, we present a novel method, in which we project a bi-color fringe pattern that is consisted of two interlaced RGB base color fringe patterns with π phase difference onto the object using digital light projector and the deformed color pattern is captured by color digital camera. Then the deformed color fringe pattern is decoded into two individual fringe patterns with π phase difference using image-separating technique. After modifying their averages and contrast, we subtract one of the two fringe patterns from the other to eliminate zero spectra. Compared with π phase-shifting technique, the obvious advantage of this method is that only one fringe pattern is needed to remove the zero spectra and raise the measurable slope of height variation nearly three times while no phase shifting device needed. Computer simulation and experiments verify our method.

Three-dimension (3-D) digitization of tooth is becoming an important diagnostic tool of dentistry for the quantitative medicine investigations. In this paper, an optical measurement instrument for tooth data acquisition based on the principle of structured illumination was developed. The instrument consists of a structured illumination optics, a stepping motor driven phase shifting device, a commercial CCD camera system with frame grabber interface and a control personal computer. Because there is no possibility of watching the system directly in the mouth, the measurements were still restricted to plaster casts of the tooth. With a new calibration gauge, both the phase-height mapping and 3D coordinates calibration could be done simultaneously through only one measurement. Additionally, to recover complex shape distribution of the tooth, a phase unwrapping procedure is proposed. The effectiveness of the proposed method is demonstrated by experimental results.

Three-dimensional (3-D) automatic measurement of an object is widely used in many fields. In Biology and Medicine society, it can be applicable for surgery, orthopedics, viscera disease analysis and diagnosis etc. Here a new fast method to measure the 3D surface of human heart is proposed which can provide doctors a lot of information, such as the size of heart profile, the sizes of the left or right heart ventricle, and the curvature center and radius of heart ventricle, to fully analyze and diagnose pathobiology of human heart. The new fast method is optically and noncontacted and based upon the Phase Measurement Profilometry (PMP), which has higher measuring precision. A human heart specimen experiment has verified our method.

A new method for the system calibration in phase-measuring profilometry (PMP) is presented. A new calibration gauge containing four virtual calibration planes is designed. With this calibration gauge, both the phase-height mapping and 3D coordinates calibration could be done simultaneously through only one measurement. Additionally, to recover continuous phase distribution of all steps with same height, an iterative procedure is proposed. The effectiveness of the proposed method is demonstrated by experimental results. (Summary only available)

Poly(acrylic acid-co-methyl methacrylate)–cetyltrimethylammonium bromide (P(AA-co-MMA)–C16TAB) complex has shape memory behavior due to the formation of crystalline aggregates among the long alkyl chains of C16TAB in the complex, and can be regarded as a novel shape memory network.

Phase measuring profilometry using structured illumination with a digital micro-mirror device(DMD) has been extensively studied because of its advantage of the programmable projection. In this paper we discussed the effect of intensity transfer function of the commercial projector with DMD, analyzed the influence of the intensity transfer function and the nonlinear of detector on the quantity of projected sinusoidal fringe and the accuracy of phase measurement, and proposed the correction method for intensity transfer function of DMD. A DMD based phase measuring profilometry system includes a commercial projector with DMD, a CCD camera and a fringe pattern analysis and processing unit. The experiments show that with the correction of the intensity transfer function of the projector the phase measurement accuracy has been improved obviously.

We use the micro-scanning technique to eliminate the frequency aliasing caused by sub-sampling in Fourier trans-form profilometry (FTP). It has been discussed that in FTP correct 3-D surface shape retrieval can be obtained only when the slope of the height variation of the measured object is limited within maximum measurement range. If this condition is not satisfied, it is im-possible to obtain correct retrieval because of shadows existed in the fringe pattern. In a crossed-optical-axes system for FTP, a smaller included angle between axis of the projection and the detection system is set to avoid the frequency alias caused by shadows. But the smaller the included angle is, the lower the phase sensitivity in FTP. That is, a small phase error can cause a large height distribution error. In order to eliminate this kind of error, we should project a dense grating image onto an object to reduce equivalent wavelength of fringe. At the same time, we need a high resolution CCD to record the fringe pattern to satisfy the sampling theory. When there is not suitable high resolution CCD, the sub-sampled fringe is obtained. In this paper, we discuss how to combine a cor-rect fringe from sub-sampling fringe patterns using micro-scanning technique in FTP in theory. Computer simulations experiments have proved our analysis.

The shoeprint impressions of suspect left at the crime scene can sometimes tell investigators what type of shoes to be looked for. These shoeprint impressions as one of the important evidence are useful in the detection of criminals. In this paper we propose a novel technique for identifying and analyzing the 3D characteristics of shoeprint impressions. We also design 3D shoeprint impression analysis system based on the combination the 3D shape measurement with structured illumination and fringe pattern analysis. We give a detail discussion on the principle and configuration of the system. Laboratory experiments show the technique is efficient in the detection of shoeprint and in the offering the reference for judicial evidence.

A Fourier transform deinterlacing algorithm (FTDA) is proposed to eliminate the blurring and dislocation of the fringe patterns on a moving object captured by an interlaced scanning colour camera in phase measuring profilometry (PMP). Every frame greyscale fringe from three colour channels of every colour fringe is divided into even and odd field fringes respectively, each of which is respectively processed by FTDA. All of the six frames deinterlaced fringes from one colour fringe form two sets of three-step phase-shifted greyscale fringes, with which two 3D shapes corresponding to two different moments are reconstructed by PMP within a frame period. The deinterlaced fringe is identical with the exact frame fringe at the same moment theoretically. The simulation and experiments show its feasibility and validity. The method doubles the time resolution, maintains the precision of the traditional phase measurement profilometry, and has potential applications in the moving and online object's 3D shape measurements.

On-line phase measuring profilometry (OPMP) for a rotating object is proposed. N frames of circular sinusoidal grating patterns are designed in advance, in which the transmittance along the radial direction is sinusoidal and there is a fixed shifting phase pitch of 2π/N between every adjacent two grating patterns along the radial direction. While the measured object is rotating, the designed grating patterns are projected onto the rotating object by digital light processing and the corresponding deformed patterns caused by the object at different positions are captured by a charge coupled device camera. By pixel matching and rotation transformation with special marks, N frames of the deformed patterns of the object at the same position can be extracted. Hence, the rotating object can be reconstructed by the extracted deformed patterns. The results of computer emulation and experiment show the feasibility and validity of the proposed OPMP. Either the maximum measurement absolute error is 0.118 mm or the maximum root mean square error is 0.077 mm in the measured region of 0 to 25 mm.

Root exudates were collected from radish and rape plants grown in P sufficient and P deficient nutrient solution. In radish, tartaric, malic and succinic acids were the dominant organic acids which increased between 15 times (succinic acid) and 60 times (malic acid) under P deficient conditions. In another experiment in quartz sand culture supplied with either Ca3(PO4)2 or AlPO4, radish utilized P from AlPO4 much better than from Ca3(PO4)2 whereas the opposite was true for rape. The results demonstrated the role of a particular organic acid in mobilizing sparingly soluble P and were in accordance with the preferential growth of two plants on acid (radish) and calcareous (rape) soils in China.

The gamma nonlinearity of the digital projector leads to obvious phase errors in the phase measuring profilometry. Based on the Fourier spectrum analysis of the captured pattern, a robust gamma correction method is proposed in this paper. An orthogonal sinusoidal grating precoded with two different known gamma values is used to evaluate the gamma value of the pattern. The evaluated gamma value is then encoded into the computer-generated phase-shifting fringe patterns before the fringe patterns are sent to the digital projector, which makes the captured fringe patterns well-sinusoidal and alleviates the phase errors caused by the gamma nonlinearity. Compared with other gamma correction methods, only one captured pattern is needed to evaluate the gamma value without loss of the accuracy. With the proposed method, a fast and accurate three-dimensional shape measurement can be achieved using the conventional three-step phase-shifting algorithm. Experiments have verified its feasibility and validity.

An improved algorithm for phase-to-height mapping in phase-measuring profilometry (PMP) is proposed, in which the phase-to-height mapping relationship is no longer restricted to the condition that the optical axes of the imaging system must be orthogonal to the reference plane in the basic PMP. Only seven coefficients independent of the coordinate system need to be calibrated, and the system calibration can be accomplished using only two different gauge blocks, instead of more than three different standard planes. With the proposed algorithm, both the phase measurement and system calibration can be completed simultaneously, which makes the three-dimensional (3-D) measurement faster and more flexible. Experiments have verified its feasibility and validity.

A three dimensional (3-D) measurement method with orthogonal composite grating aided by fringe contrast and background calibration is proposed. Due to spectrum overlap, we find that the contrast and background of each deformed phase-shifting fringe demodulated from the captured composite fringe image is changed differently, which violates the principle that the contrast and background between any two deformed fringes must be uniform in the traditional 3-D measurement method with orthogonal composite grating, and therefore results in measurement error. We acquire the phase-shifting sinusoidal fringes from the composite fringe image captured on the reference plane, and the zero- and first-order spectra of the sinusoidal fringes can be obtained by filtering in the spatial frequency domain. Then the ratio contrast and background coefficients between the phase-shifting sinusoidal fringes can be calculated. When an object is measured, the contrast and background of the demodulated deformed fringes can be calibrated by these ratio coefficients. A new 3-D measurement mathematical model is set up to reconstruct the object. Experiments prove the new method can effectively restrain the effect of spectrum overlap, and can improve the measurement accuracy more than 1 time.

An optical method for shape and deformation measurement of a rotating blade, which is based on Fourier transform profilometry FTP and the stroboscopic effect, is proposed and has been verified by experiments. The integrated principles of the method, the process of 3-D phase unwrapping, and the detailed design of the synchronization con- trol unit are discussed. Experimental results on a commercial electric fan prove that FTP can reconstruct the shape of a rotating blade efficiently and reveal its deformation different times clearly by using stroboscopic structured illumination. This method can be used for studying high-speed motion with rapid periodic signals. © 2005 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.2127927 Subject terms: Fourier transform profilometry; 3-D shape measurement; stroboscope; dynamic 3-D visualization; structured illumination; phase unwrapping; rotating blade.

A new method for both the phase-height mapping and the 3-D coordinate calibration in phase-measuring profilometry (PMP) is presented. A calibration gauge containing four virtual calibration planes is designed. The application of the calibration gauge avoids the translation of the standard plane during the calibration process. Furthermore, circular steps are designed to calibrate lateral coordinates automatically. With this calibration gauge, both the phase-height mapping and lateral coordinates calibration could be done simultaneously through only one measurement. Additionally, to recover a continuous phase distribution of all the steps with the same height, an iterative procedure is proposed. The effectiveness of the proposed method is demonstrated by experimental results.

The accuracy of Fourier transform profilometry (FTP) is greatly influenced by the aliasing between foundational spectra and zero and higher order spectra. We present a novel method in which a bicolor sinusoidal fringe pattern that consists of two interlaced RGB format base color fringe patterns with π phase difference is projected onto the object through a digital light projector and the deformed color pattern is captured by a color digital camera. Then the deformed color fringe pattern is decoded into two individual fringe patterns with π phase difference using a color-separating technique. After calibration of means and contrast, we subtract one of the two fringe patterns from the other to eliminate the aliasing between foundational spectra and zero and higher order spectra. We provide the calibration algorithm of means and contrast. Computer simulation and experiment verify that this method has an obvious advantage. Compared with the π-phase-shifting technique, only one fringe pattern is required to remove the zero spectra and raise the measurable slope of height variation nearly three times, and no phase-shifting device is required in the experimental setup.

The contraction of poly[(methacrylic acid)-co-(methyl methacrylate)] [P(MAA-co-MMA)] gel induced by complexation with linear poly(ethylene glycol) (PEG) is quite different from that of poly(acrylic acid) (PAA) or poly(methacrylic acid) (PMAA) gels. The effects of molecular weight and concentration of PEG, cross-linking density and composition of the gel, and the pH of the external solution on the conformational transitions of P(MAA-co-MMA) gels were investigated. A special feature of the conformational transitions for the P(MAA-co-MMA) gel/PEG system is the absence of a certain range of PEG concentrations where a reswelling of the collapsed gel is observed. The strong hydrophobicity of PMMA units will improve the PEG/network hydrophobic interactions and thereby stabilize the formed complex inside the gel network.