Three-dimensional Color Research Articles

Investigation of strength of shaped elements of the main gas pipeline

The research has been carried out for the purpose of a complex numerical three-dimensional modeling of the stressed state of taps and tees of main gas pipelines taking into account the gas-dynamic processes occurring in these shaped elements and the temperature difference in their walls. A 3D modeling of the elbow with a 90° angle and a reinforcing pad on the main line and the drainage of the passage line of the trunk of the main gas pipeline has been carried out. There has been studied the gas flow with 3D models of shaped elements of the main gas pipeline by means of the CFD modeling. The simulation has been рerformed for the equidistant tees in which the entire flow from the main stream flows into its branch. The mathematical model is based on the solution of the Navier–Stokes equation system, continuity equation, closed by a two-parametric k -e model of the Launder–Sharma turbulence with corresponding initial and boundary conditions. The simulation results are visualized in the ANSYS Fluent R18.2 Academic Postprocessor by constructing the pressure fields on the contours and in the longitudinal and transverse sections of shaped elements. The exact values of pressure at different points of the inner cavity of the shaped elements have been determined, the places of rise and fall of pressure identified. There have been performed the simulation of the temperature difference in the walls of the drainage, the trunk of the main gas pipeline in the module ANSYS Transient Thermal. The results of CFD and temperature modeling were imported into the mechanical module ANSYS Static Structural, where the finite element method was used to simulate the stressed state of the shaped elements of the main gas pipeline, taking into account the gas-dynamic processes occurring in their internal cavity and the temperature difference in the walls. The results of the simulation have been visualized by constructing a three-dimensional color fields of equivalent von Mises stresses in the tee and in the elbow. The places of the maximum equivalent stresses in the wall of the studied shaped elements have been revealed.

Combined flow-based imaging assessment of optimal cardiac resynchronization therapy pacing vector: a\xa0case report

BackgroundThere are still many pendent issues about the effective evaluation of cardiac resynchronization therapy impact on functional mitral regurgitation. In order to reduce the intrinsic difficulties of quantification of functional mitral regurgitation itself, an automatic quantification of real-time three-dimensional full-volume color Doppler transthoracic echocardiography was proposed as a new, rapid, and accurate method for the assessment of functional mitral regurgitation severity. Recent studies suggested that images of left ventricle flow by echo-particle imaging velocimetry could be a useful marker of synchrony. Echo-particle imaging velocimetry has shown that regional anomalies of synchrony/synergy of the left ventricle are related to the alteration, reduction, or suppression of the physiological intracavitary pressure gradients.Case summaryWe describe a case in which the two technologies are used in combination during acute echocardiographic optimization of left pacing vector in a 63-year-old man, Caucasian, who showed worsening heart failure symptoms a few days after an implant, and the effect of the device’s optimization at 6-month follow-up.DiscussionThe degree of realignment of hemodynamic forces, with quantitative analysis of the orientation of blood flow momentum (φ), can represent improvement of fluid dynamics synchrony of the left ventricle, and explain, with a new deterministic parameter, the effects of cardiac resynchronization therapy on functional mitral regurgitation. Real-time three-dimensional color flow Doppler quantification is feasible and accurate for measurement of mitral inflow, left ventricular outflow stroke volumes, and functional mitral regurgitation severity.ConclusionThis clinical case offers an innovative and accurate approach for acute echocardiographic optimization of left pacing vector. It shows clinical utility of combined three-dimensional full-volume color Doppler transthoracic echocardiography/echo-particle imaging velocimetry assessment to increase response to cardiac resynchronization therapy, in terms of reduction of functional mitral regurgitation, improving fluid dynamics synchrony of the left ventricle.

Infrared image enhancement model based on gravitational force and lateral inhibition networks

Problems such as low contrast, noise, and edge blur are often encountered in color infrared images produced by infrared cameras. To solve these problems, we propose a new image enhancement algorithm based on the gravitational force and lateral inhibition network. First, information on total gravitational force for each dimension of the color infrared image was obtained. These two-dimensional three gray level images obtained using three-dimensional color properties help to define noise, edge and region within each dimension. Secondly, these three gray level images were subjected to a dual threshold value. A mean filter was used to reduce noise, while the lateral inhibition network was used for resolution and edge detection, and the regional gravity factor was used for contrast control. Finally, each dimension was combined again and a color enhanced image was produced. This study sets out to develop a method of enhancement images for infrared image analysis in cooling systems. The images used in the study are made up of a compressor, a condenser, and an evaporator belonging to the cooling system. The implementation of our method is simple and easy to understand and yields more accurate results. The experimental results show that the proposed method can eliminate noise, blur, and low contrast, and can also improve the details of infrared images better than other methods.

Reliability of three-dimensional color flow Doppler and two-dimensional pulse wave Doppler transthoracic echocardiography for estimating cardiac output after cardiac surgery

BackgroundThree-dimensional color flow Doppler (3DCF) is a new convenient technique for cardiac output (CO) measurement. However, to date, no one has evaluated the accuracy of 3DCF echocardiography for CO measurement after cardiac surgery. Therefore, this single-center, prospective study was designed to evaluate the reliability of three-dimensional color flow and two-dimensional pulse wave Doppler (2D-PWD) transthoracic echocardiography for estimating cardiac output after cardiac surgery.MethodsPost-cardiac surgical patients with a good acoustic window and a low dose or no dose of vasoactive drugs (norepinephrine < 0.05 μg/kg/min) were enrolled for CO estimation. Three different methods (third generation FloTrac/Vigileo™ [FT/V] system as the reference method, 3DCF, and 2D-PWD) were used to estimate CO before and after interventions (baseline, after volume expansion, and after a dobutamine test).ResultsA total of 20 patients were enrolled in this study, and 59 pairs of CO measurements were collected (one pair was not included because of increasing drainage after the dobutamine test). Pearson’s coefficients were 0.260 between the CO-FT/V and CO-PWD measurements and 0.729 between the CO-FT/V and CO-3DCF measurements. Bland-Altman analysis showed the bias between the absolute values of CO-FT/V and CO-PWD measurements was − 0.6 L/min with limits of agreement between − 3.3 L/min and 2.2 L/min, with a percentage error (PE) of 61.3%. The bias between CO-FT/V and CO-3DCF was − 0.14 L/min with limits of agreement between − 1.42 L /min and 1.14 L/min, with a PE of 29.9%. Four-quadrant plot analysis showed the concordance rate between ΔCO-PWD and ΔCO-3FT/V was 93.3%.ConclusionsIn a comparison with the FT/V system, 3DCF transthoracic echocardiography could accurately estimate CO in post-cardiac surgical patients, and the two methods could be considered interchangeable. Although 2D-PWD echocardiography was not as accurate as the 3D technique, its ability to track directional changes was reliable.

The Cambridge Colour Test: Reliability of discrimination trivectors in colour space

Background: The reliable assessment of colour discrimination has become increasingly important as some ophthalmic diseases and systemic conditions manifest themselves via acquired impairments of colour vision. The Cambridge Colour Test (CCT) is a computerised procedure, developed using the basic principles of traditional pseudoisochromatic plates to evaluate colour function or discrimination. Aim: The study investigated reliability of the CCT, with emphasis on the Trivector subtest, which measures thresholds along the three protan, deutan and tritan confusion lines to probe the sensitivity of the long, medium and short wavelength cones. Setting: The study used a prospective observational and quantitative design and took place in a research and clinical environment within the Department of Optometry at the University of Johannesburg, South Africa. Participants were 20 young adults of both genders aged 19–24 years with normal colour vision. Methods: Two measurements (test and retest) of the Trivector test were measured monocularly (right eye) for all participants to assess the reliability of repeated measurements. Reliability was assessed using coefficients of repeatability, coefficients of variation and Bland–Altman plots with limits of agreement (LoA). Results: Outcomes for the Bland–Altman LoA showed good intra-individual agreement and coefficients of repeatability and reliability revealed generally high test–retest repeatability. Multivariate stereo-pair scatter plot comparisons of means and differences of test and retest measurements show that points cluster tightly within the same region in the three-dimensional colour space, and the centroids of the ellipsoids representing the mean differences are close to the origin at zero. Conclusion: Although departure from normality and outlying values can have important influences, essentially the CCT provides very similar test and retest results for the Trivector test.

LEFT VENTRICULAR STROKE VOLUME ASSESSMENT BY AUTOMATED THREE DIMENSIONAL COLOR FLOW DOPPLER ECHOCARDIOGRAPHY: A RELIABLE ALTERNATIVE TO TWO DIMENSIONAL PULSE DOPPLER ECHOCARDIOGRAPHY

Automated quantitation of stroke volume (SV) by three-dimensional volume color flow Doppler (3D-VCFD) in the left ventricular outflow tract (LVOT) has been validated against cardiac MRI (CMR) as an accurate and reproducible technique and does not rely on unidimensional measure of LVOT area. We

Glaucoma Diagnosis with Machine Learning Based on Optical Coherence Tomography and Color Fundus Images.

This study aimed to develop a machine learning-based algorithm for glaucoma diagnosis in patients with open-angle glaucoma, based on three-dimensional optical coherence tomography (OCT) data and color fundus images. In this study, 208 glaucomatous and 149 healthy eyes were enrolled, and color fundus images and volumetric OCT data from the optic disc and macular area of these eyes were captured with a spectral-domain OCT (3D OCT-2000, Topcon). Thickness and deviation maps were created with a segmentation algorithm. Transfer learning of convolutional neural network (CNN) was used with the following types of input images: (1) fundus image of optic disc in grayscale format, (2) disc retinal nerve fiber layer (RNFL) thickness map, (3) macular ganglion cell complex (GCC) thickness map, (4) disc RNFL deviation map, and (5) macular GCC deviation map. Data augmentation and dropout were performed to train the CNN. For combining the results from each CNN model, a random forest (RF) was trained to classify the disc fundus images of healthy and glaucomatous eyes using feature vector representation of each input image, removing the second fully connected layer. The area under receiver operating characteristic curve (AUC) of a 10-fold cross validation (CV) was used to evaluate the models. The 10-fold CV AUCs of the CNNs were 0.940 for color fundus images, 0.942 for RNFL thickness maps, 0.944 for macular GCC thickness maps, 0.949 for disc RNFL deviation maps, and 0.952 for macular GCC deviation maps. The RF combining the five separate CNN models improved the 10-fold CV AUC to 0.963. Therefore, the machine learning system described here can accurately differentiate between healthy and glaucomatous subjects based on their extracted images from OCT data and color fundus images. This system should help to improve the diagnostic accuracy in glaucoma.

Chromatic and luminance sensitivity for skin and skinlike textures.

Despite the importance of the appearance of human skin for theoretical and practical purposes, little is known about visual sensitivity to subtle skin-tone changes, and whether the human visual system is indeed optimized to discern skin-color changes that confer some evolutionary advantage. Here, we report discrimination thresholds in a three-dimensional chromatic-luminance color space for natural skin and skinlike textures, and compare these to thresholds for uniform stimuli of the same mean color. We find no evidence that discrimination performance is superior along evolutionarily relevant color directions. Instead, discriminability is primarily determined by the prevailing illumination, and discrimination ellipses are aligned with the daylight locus. More specifically, the area and orientation of discrimination ellipses are governed by the chromatic distance between the stimulus and the illumination. Since this is true for both uniform and textured stimuli, it is likely to be driven by adaptation to mean stimulus color. Natural skin texture itself does not confer any advantage for discrimination performance. Furthermore, we find that discrimination boundaries for skin, skinlike, and scrambled skin stimuli are consistently larger than those for uniform stimuli, suggesting a possible adaptation to higher order color statistics of skin. This is in line with findings by Hansen, Giesel, and Gegenfurtner (2008) for other natural stimuli (fruit and vegetables). Human observers are also more sensitive to skin-color changes under simulated daylight as opposed to fluorescent light. The reduced sensitivity is driven by a decline in sensitivity along the luminance axis, which is qualitatively consistent with predictions from a Von Kries adaptation model.

Facial Tightening Following a Single Acoustic Wave Treatment Using Focused and Radial Acoustic Waves

Background: Acoustic wave has been used for many medical purposes, and although it is widely applied in cosmetic procedures, it has not been conducted for facial rejuvenation and tightening. Acoustic wave has been proven to penetrate deeper than subcutaneous tissue, independent of skin color, and to be beneficial for skin tightening and body contouring. Objective: To evaluate the effectiveness of a single acoustic wave treatment session using unique focused and radial acoustic waves for facial tightening. Participants: Sixty Asian patients were treated between the years 2016 and 2018. The single acoustic wave treatment session consists of focused long planar acoustic pulses thought to have an effect on cells and their metabolism resulting in an increased release of fat, and radial short acoustic pulses thought to have an effect on tissues activating blood and lymphatic flow. Patients did not undergo any form of medical aesthetic treatment during the study. Measurements: Digital photographs and three-dimensional imaging were used to evaluate the results. Results: Objective assessments with digital photographs and superimposed three-dimensional color images showed preferable facial tightening effects and marked volumetric reduction on the lower one-third of the face. These results were obtained without the edematous reactions observed in laser and radiofrequency therapies, and were sustained up to 12 months. All of the patients reported satisfaction with the results and convenience of the procedure. Complications were minor and transitory, consisting of a slight tingly sensation to the teeth during the treatment, and mild erythema resolving within 5 hours. Side effects were not observed. Conclusions: The advantages of the single acoustic wave treatment are the high potency of facial tightening effects, reduction of discomfort and side effects. Taken together, these characteristics facilitate the ability to give repeated treatments and provide an alternative or adjunct treatment for patients with improved results.

Controlling upconversion luminescence patterns in space with red emission enhancement from a single fluoride microcrystal by tuning the excitation mode.

The ability to control the upconversion (UC) luminescence patterns in space from lanthanide-doped UC luminescence materials is very important for many applications including three-dimensional color displays, optical waveguides and optical communication. In this work, the fascinating UC luminescence patterns could be adjusted from the blue or green flower-like emission pattern to the red flame-like irradiation pattern with a red luminescence enhancement from a single β-NaYF4:Yb3+/(Tm3+ or Er3+) microcrystal (MC) by varying the excitation position. The red-to-blue (R/B) and the red-to-green (R/G) emission intensity ratios from the single MC particle that the focal point position of excitation NIR laser is on the side lace are much stronger than that in the case of the focused laser beam on the center. We think that the physical mechanism from the changes in the luminescence pattern and the emission intensity ratio is explained by the optical waveguide effect based on the total reflection effect. These results provide a new strategy for facilitating fundamental investigations of the UC micro/nano-materials, which will lead to promising applications in three-dimensional color display, optical waveguides and optical communication.

Prediction of kiwifruit orchard characteristics from satellite images

The dry matter content of New Zealand kiwifruit is currently measured using destructive testing of a 90-fruit sample. Dry matter content varies from 14 to 20% with a standard deviation of 1.05% in the test measurement. This work investigates the use of multispectral data from satellite images of kiwifruit orchards to predict the dry matter of both green and gold kiwifruit. A novel method is developed that reduces the four-dimensional satellite data to three-dimensional unit color vectors and these show a strong linear relationship with measured dry matter. Regression on the data from a set of 20 ‘training’ orchards yielded predictions of dry matter with a standard deviation of 0.76%. When the resulting model was applied to nine test orchards the standard deviation of predicted dry matter was 0.73%. The prediction of dry matter was accurate even when applied to images taken when the fruit was too immature for the standard dry matter measurement test. Therefore, satellite image data may provide a more accurate and non-destructive alternative to the standard 90-fruit test method. It can also provide a way to visualize the variation in dry matter content of the fruit in an orchard; showing regions that would benefit from remedial action and defining areas where fruit harvesting is optimal. Several vegetation indices, derived from satellite image data, are reported in the literature. The strength of the linear correlation between dry matter and twelve common vegetation indices was tested but was found to be much weaker than the correlation developed in this research.

Optimal B-spline Mapping of Flow Imaging Data for Imposing Patient-specific Velocity Profiles in Computational Hemodynamics.

Objective:We propose a novel method to obtainmap patient-specific blood velocity profiles (obtained from imaging data such as 2D flow MRI or 3D colour Doppler ultrasound) and map them to geometric vascular models suitable to perform CFD simulations of haemodynamics. We describe the implementation and utilisation of the method within an open-source computational hemodynamics simulation software (CRIMSON).Methods:tThe proposed method establishes point-wise correspondences between the contour of a fixed geometric model and time-varying contours containing the velocity image data, from which a continuous, smooth and cyclic deformation field is calculated. Our methodology is validated using synthetic data, and demonstrated using two different in-vivo aortic velocity datasets: a healthy subject with normal tricuspid valve and a patient with bicuspid aortic valve.Results:We compare the performance of our method with results obtained with the state-of-the-art Schwarz-Christoffel method, in terms of preservation of velocities and execution time. Our method is as accurate as the Schwarz-Christoffel method, while being over 8 times faster. The proposed method can preserve either the flow rate or the velocity field through the surface, and can cope with inconsistencies in motion and contour shape.Conclusions:Our results show that the method is as accurate as the Schwarz-Christoffel method in terms of maintaining the velocity distributions, while being more computationally efficient.Our mapping method can accurately preserve either the flow rate or the velocity field through the surface, and can cope with inconsistencies in motion and contour shape.Significance:The proposed method and its integration into the CRIMSON software enable a streamlined approach towards incorporating more patient-specific data in blood flow simulations.

Laser Scanners for High-Quality 3D and IR Imaging in Cultural Heritage Monitoring and Documentation

Digital tools as 3D (three-dimensional) modelling and imaging techniques are having an increasing role in many applicative fields, thanks to some significative features, such as their powerful communicative capacity, versatility of the results and non-invasiveness. These properties are very important in cultural heritage, and modern methodologies provide an efficient means for analyzing deeply and virtually rendering artworks without contact or damage. In this paper, we present two laser scanner prototypes based on the Imaging Topological Radar (ITR) technology developed at the ENEA Research Center of Frascati (RM, Italy) to obtain 3D models and IR images of medium/large targets with the use of laser sources without the need for scaffolding and independently from illumination conditions. The RGB-ITR (Red Green Blue-ITR) scanner employs three wavelengths in the visible range for three-dimensional color digitalization up to 30 m, while the IR-ITR (Infrared-ITR) system allows for layering inspection using one IR source for analyses. The functionalities and operability of the two systems are presented by showing the results of several case studies and laboratory tests.

Non-destructive Plant Morphometric and Color Analyses Using an Optoelectronic 3D Color Microscope.

Gene function discovery in plants, as other plant science quests, is aided by tools that image, document, and measure plant phenotypes. Tools that acquire images of plant organs and tissues at the microscopic level have evolved from qualitative documentation tools, to advanced tools where software-assisted analysis of images extracts quantitative information that allows statistical analyses. They are useful to perform morphometric studies that describe plant physical characteristics and quantify phenotypes, aiding gene function discovery. In parallel, non-destructive, versatile, robust, and user friendly technologies have also been developed for surface topography analysis and quality control in the industrial manufacture sector, such as optoelectronic three-dimensional (3D) color microscopes. These microscopes combine optical lenses, electronic image sensors, motorized stages, graphics engines, and user friendly software to allow the visualization and inspection of objects of diverse sizes and shapes from different angles. This allow the integration of different automatically obtained images along the Z axis of an object, into a single image with a large depth-of-field, or a 3D model in color. In this work, we explored the performance of an optoelectronic microscope to study plant morphological phenotypes and plant surfaces in different model species. Furthermore, as a “proof-of-concept,” we included the phenotypic characterization (morphometric analyses at the organ level, color, and cell size measurements) of Arabidopsis mutant leaves. We found that the microscope tested is a suitable, practical, and fast tool to routinely and precisely analyze different plant organs and tissues, producing both high-quality, sharp color images and morphometric and color data in real time. It is fully compatible with live plant tissues (no sample preparation is required) and does not require special conditions, high maintenance, nor complex training. Therefore, though barely reported in plant scientific studies, optoelectronic microscopes should emerge as convenient and useful tools for phenotypic characterization in plant sciences.

Projecting three-dimensional color codes onto three-dimensional toric codes

Toric codes and color codes are two important classes of topological codes. Kubica, Yoshida, and Pastawski showed that any $D$-dimensional color code can be mapped to a finite number of toric codes in $D$-dimensions. In this paper we propose an alternate map of 3D color codes to 3D toric codes with a view to decoding 3D color codes. Our approach builds on Delfosse's result for 2D color codes and exploits the topological properties of these codes. Our result reduces the decoding of 3D color codes to that of 3D toric codes. Bit flip errors are decoded by projecting on one set of 3D toric codes while phase flip errors are decoded by projecting onto another set of 3D toric codes.

The diagnostic value of two-dimensional ultrasound and three-dimensional color Doppler ultrasonography combined with AFP and CK in the diagnosis of scar uterus and placenta previa implantation

Objective To compare the diagnostic value of two-dimensional ultrasound and three-dimensional color Doppler ultrasonography combined with alpha-fetoprotein (AFP) and creatine kinase (CK) in the diagnosis of scar uterus and placenta previa implantation. Methods 120 cases of pregnancy delivery documented in our hospital from February 2013 to January 2017 were selected as the research object. All cases were divided into implantation group and non implantation group accorded to the pathological diagnosis. The implantation group of 44 cases were diagnosed as placenta previa implantation and the non implantation group of 76 cases were diagnosed as non placenta previa implantation. Two-dimensional ultrasound and three-dimensional color Doppler ultrasound diagnosis characteristic and effect in the two groups were recorded. The AFP, CK expression in the two groups were also detected. Results AFP and CK expression were detected in the serum levels of all pregnant women. The AFP and CK expression in the implantation group were (152.80±11.66)μg/L and (125.98±16.67)IU/L, significantly higher than non implantation group [(80.65±22.84)μg/L and (77.55±23.32)IU/L, P<0.05]. Ultrasonic diagnosis of placenta implantation in 39 cases, and non placenta previa implantation81 cases ; there were 38 cases of placenta accreta and 82 cases of non placenta previa implantation judged by AFP and CK expression; 43 cases of placenta previa implantatio, and 77 cases of non placenta previa implantation judged by ultrasound combined with AFP and CK. So the combined diagnostic sensitivity were significantly higher than that of single diagnostic sensitivity (P<0.05). The receiver operating characteristic (ROC) curve shows that the area under the curve of ultrasound is =0.879, AFP and CK=0.835, and the ultrasound was better than AFP and CK. Conclusions The two-dimensional ultrasound and three-dimensional color Doppler ultrasonography combined with AFP and CK in the diagnosis of scar uterus and placenta previa implantation can improve the diagnostic effect, and they have very good application values. Key words: Placenta previa/US; Placenta accreta/US/BL; Uterus/US; Cicatrix; Ultrasonography, Doppler, color; Alpha-fetoproteins/BL; Creatine kinase/BL

Three-Dimensional Color Code Thresholds via Statistical-Mechanical Mapping.

Three-dimensional (3D) color codes have advantages for fault-tolerant quantum computing, such as protected quantum gates with relatively low overhead and robustness against imperfect measurement of error syndromes. Here we investigate the storage threshold error rates for bit-flip and phase-flip noise in the 3D color code (3DCC) on the body-centered cubic lattice, assuming perfect syndrome measurements. Inparticular, by exploiting a connection between error correction and statistical mechanics, we estimate the threshold for 1D stringlike and 2D sheetlike logical operators to be p_{3DCC}^{(1)}≃1.9% and p_{3DCC}^{(2)}≃27.6%. We obtain these results by using parallel tempering MonteCarlo simulations to study the disorder-temperature phase diagrams of two new 3D statistical-mechanical models: the four- and six-body random coupling Ising models.

INFORMATION EXTRACTION OF TOURIST GEOLOGICAL RESOURCES BASED ON 3D VISUALIZATION REMOTE SENSING IMAGE

Abstract. Tourism geological resources are of high value in admiration, scientific research and universal education, which need to be protected and rationally utilized. In the past, most of the remote sensing investigations of tourism geological resources used two-dimensional remote sensing interpretation method, which made it difficult for some geological heritages to be interpreted and led to the omission of some information. This aim of this paper is to assess the value of a method using the three-dimensional visual remote sensing image to extract information of geological heritages. skyline software system is applied to fuse the 0.36 m aerial images and 5m interval DEM to establish the digital earth model. Based on the three-dimensional shape, color tone, shadow, texture and other image features, the distribution of tourism geological resources in Shandong Province and the location of geological heritage sites were obtained, such as geological structure, DaiGu landform, granite landform, Volcanic landform, sandy landform, Waterscapes, etc. The results show that using this method for remote sensing interpretation is highly recognizable, making the interpretation more accurate and comprehensive.

Tunable flower-like upconversion emission and directional red radiation in a single NaYF4:Yb3+/Tm3+ microcrystal particle

Rear earth doped upconversion (UC) luminescence materials have attracted considerable attentions in color display and biological labeling due to their tunable emission colors property. In this report, we designed and fabricated NaYF4: Yb3+/Tm3+ microcrystals with novel morphology, which exhibit some unique UC luminescence phenomena. The experimental findings show that a flower-like blue UC emission pattern and the directional red radiation are readily manipulated by controlling the focal point position of the excitation laser on the single microcrystal particle (MP). The unique phenomena are attributed to optical waveguide effect with total internal reflection of the UC luminescence at the microcrystal-air interface. The findings not only provide a new strategy for designing UC nano-/microcrystals with particular and tunable luminescence properties, but also open a promising route for the fabrication of new optoelectronic devices and the construction of three-dimensional color display systems.

Spatially incoherent common-path off-axis color digital holography.

We describe a new method for recording spatially incoherent common-path off-axis color digital holograms. We present the theoretical and experimental evidence to demonstrate an incoherent common-path off-axis color digital holographic (ICOCH) system capable of capturing information from three-dimensional color objects under incoherent illumination, both in transmission and reflection modes. Fresnel incoherent correlation holography (FINCH), a common-path system, is a frequently used incoherent holography technique. Our proposed system is conceptually similar to an advanced form of FINCH; moreover, it has three advantages over this advanced form of FINCH. First, removal of the spatial light modulator makes our system simpler and more cost-effective. Second, removal of the polarizer or analyzer allows for greater light throughput. Third, the off-axis optical configuration enables separation of zero-order and twin images with only a single exposure per color rather than requiring three exposures per color for in-line holography FINCH. Therefore, we believe that this simple and cost-effective system with high light throughput can acquire incoherent holograms for different colors involving single exposure for each color, which makes the ICOCH system suitable for many applications.