scholarly journals Detection of vertical disparity in three-dimensional visualizations

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 1028-1033 ◽  
Author(s):  
Piotr Napieralski ◽  
Michał Kowalczyk
Keyword(s):  
Complete Solution ◽  
Three Dimensional ◽  
Film Material ◽  
Stable Algorithm ◽  
3D Images ◽  
Vertical Disparity ◽  
Material Quality

AbstractThis paper identifies the major types of artifacts occurring in three-dimensional materials. It focuses on the analysis of vertical disparity. The vertical disparity is the artifact of the 3D images that appears both in the film material and in the computer visualizations. The research explains the causes and consequences of the vertical disparity occurrence and presents the stable algorithm of detecting mentioned anomaly. The implementation of the developed method constitutes a complete solution enabling verification of the stereoscopic material quality. The summary of the paper contains the evaluation of the algorithm in terms of correctness and stability.

Measurements in 3D images

1991 ◽  
Vol 49 ◽  
pp. 408-409
Author(s):  
John C. Russ
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
X Rays ◽  
Traditional Use ◽  
3D Images ◽  
Confocal Scanning Laser Microscope ◽  
Hard Materials ◽  
Depth Direction ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.

scholarly journals Do 3D Face Images Capture Cues of Strength, Weight, and Height Better than 2D Face Images do?

2021 ◽  
Vol 7 (3) ◽  
pp. 209-219
Author(s):  
Iris J Holzleitner ◽  
Alex L Jones ◽  
Kieran J O’Shea ◽  
Rachel Cassar ◽  
Vanessa Fasolt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Physical Characteristics ◽  
Two Dimensional ◽  
3D Images ◽  
3D Face ◽  
Face Images ◽  
Similar Accuracy ◽  
2D And 3D ◽  
2D Images ◽  
Better Than

Abstract Objectives A large literature exists investigating the extent to which physical characteristics (e.g., strength, weight, and height) can be accurately assessed from face images. While most of these studies have employed two-dimensional (2D) face images as stimuli, some recent studies have used three-dimensional (3D) face images because they may contain cues not visible in 2D face images. As equipment required for 3D face images is considerably more expensive than that required for 2D face images, we here investigated how perceptual ratings of physical characteristics from 2D and 3D face images compare. Methods We tested whether 3D face images capture cues of strength, weight, and height better than 2D face images do by directly comparing the accuracy of strength, weight, and height ratings of 182 2D and 3D face images taken simultaneously. Strength, height and weight were rated by 66, 59 and 52 raters respectively, who viewed both 2D and 3D images. Results In line with previous studies, we found that weight and height can be judged somewhat accurately from faces; contrary to previous research, we found that people were relatively inaccurate at assessing strength. We found no evidence that physical characteristics could be judged more accurately from 3D than 2D images. Conclusion Our results suggest physical characteristics are perceived with similar accuracy from 2D and 3D face images. They also suggest that the substantial costs associated with collecting 3D face scans may not be justified for research on the accuracy of facial judgments of physical characteristics.

scholarly journals Scientific validation of three-dimensional stereophotogrammetry compared to the IGAIS clinical scale for assessing wrinkles and scars after laser treatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Helena Barcaro Machado ◽  
Ivy Dantas De Melo E. Silva ◽  
Walter Marou Pautrat ◽  
James Frame ◽  
Mohammad Najlah
Keyword(s):  
Laser Treatment ◽  
Three Dimensional ◽  
Skin Surface ◽  
Clinical Scale ◽  
3D Images ◽  
Laser Resurfacing ◽  
Before And After ◽  
Measuring Outcomes ◽  
Skin Scar ◽  
Scientific Validation

AbstractMeasuring outcomes from treatments to the skin is either reliant upon patient’s subjective feedback or scale-based peer assessments. Three-Dimensional stereophotogrammetry intend to accurately quantify skin microtopography before and after treatments. The objective of this study is comparing the accuracy of stereophotogrammetry with a scale-based peer evaluation in assessing topographical changes to skin surface following laser treatment. A 3D stereophotogrammetry system photographed skin surface of 48 patients with facial wrinkles or scars before and three months after laser resurfacing, followed immediately by topical application of vitamin C. The software measured changes in skin roughness, wrinkle depth and scar volume. Images were presented to three observers, each independently scoring cutaneous improvement according to Investigator Global Aesthetic Improvement Scale (IGAIS). As for the results, a trend reflecting skin/scar improvement was reported by 3D SPM measurements and raters. The percentage of topographical change given by the raters matched 3D SPM findings. Agreement was highest when observers analysed 3D images. However, observers overestimated skin improvement in a nontreatment control whilst 3D SPM was precise in detecting absence of intervention. This study confirmed a direct correlation between the IGAIS clinical scale and 3D SPM and confirmed the efficacy and accuracy of the latter when assessing cutaneous microtopography alterations as a response to laser treatment.

Optimisation of the drill-in behaviour of the EcoFit® SC threaded cup

2020 ◽  
Vol 65 (4) ◽  
pp. 477-484
Author(s):  
Christoph Thorwächter ◽  
Matthias Woiczinski ◽  
Inês Santos ◽  
Florian Schmidutz ◽  
Alexander Paulus ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Primary Stability ◽  
Clinical Results ◽  
Clinical Applications ◽  
Testing System ◽  
Clinical Use ◽  
Maximum Torque ◽  
3D Images ◽  
Universal Testing ◽  
Biomechanical Investigation

AbstractThreaded cups show good clinical results when implanted correctly. In clinical use, multiple cases with an incomplete placement of the EcoFit threaded cup (implantcast) were observed. This behaviour could not be explained intra- and postoperatively. The aim of this study was to compare and optimise the drill-in-behaviour of the EcoFit cup in a biomechanical investigation. EcoFit cup sizes 46, 50 and 54 mm were compared with the SC cup (Aesculap) size 50 mm. Foam blocks (Sawbones) of density 0.16 g/ml (pcf 10), 0.32 g/ml (pcf 20) and 0.48 g/ml (pcf 30) were used. After standardised placement using a universal testing system (n = 8 per group), the primary stability, the overhang of the cups and the drill-in behaviour were measured. Overreamings of 1 and 2 mm were performed (pcf 20, n = 8) for the EcoFit cup size 50 and the primary stability as well as the overhang measurements were examined. Measurements of the cup diameter, thread depth and thread pitch were performed on three-dimensional (3D) images of the cup size 50 mm. The drill-in behaviour was different between the EcoFit and the SC cups. Even with maximum torque, the EcoFit cup could not be positioned as deep as the SC cup in standard reaming conditions (overhang of 1.1 ± 0.4 mm for the EcoFit size 50 in pcf 20 and of −0.01 ± 0.2 mm for the SC cup). The primary stability was lower for the EcoFit cup in comparison to the SC cup (128.8 ± 3.2 Nm vs. 138.6 ± 9.1 Nm, p = 0.0291). With overreaming to 51 mm, a deeper positioning of the EcoFit was possible (overlap of −0.3 ± 0.1, comparable to the SC cup). The overreaming of the cavity also led to a significantly higher primary stability of 143.4 ± 3.7 Nm (p < 0.001) comparable to the unaltered condition (128.8 ± 3.2 Nm). Overreaming to 52 mm had no further advantage in terms of primary stability or overhang. The geometric measurements showed significant differences as well. The previously clinically observed difficulties in inserting the cup were confirmed by this study. By overreaming to 51 mm, the drill-in behaviour, the primary stability and the measured overhang were comparable to the reference cup. The obtained results suggest that the extension of the acetabulum cavity to 51 mm while using the implantcast EcoFit size 50 should be implemented in clinical applications.

A stable algorithm for bed friction in three-dimensional shallow sea modal models

1992 ◽  
Vol 14 (4) ◽  
pp. 477-493 ◽  
Author(s):  
A. M. Davies ◽  
J. N. Aldridge
Keyword(s):  
Three Dimensional ◽  
Shallow Sea ◽  
Stable Algorithm ◽  
Bed Friction

Vertical Disparity Can Alter Perceived Direction

Perception ◽  
10.1068/p3440 ◽  
2002 ◽  
Vol 31 (11) ◽  
pp. 1323-1333 ◽  
Author(s):  
Ellen M Berends ◽  
Raymond van Ee ◽  
Casper J Erkelens
Keyword(s):  
Three Dimensional ◽  
Visual Scene ◽  
Eye Position ◽  
Vertical Disparity ◽  
Vertical Scale ◽  
The Common ◽  
The Right ◽  
The Relationship ◽  
Straight Ahead ◽  
Stimulus Direction

It has been well established that vertical disparity is involved in perception of the three-dimensional layout of a visual scene. The goal of this paper was to examine whether vertical disparities can alter perceived direction. We dissociated the common relationship between vertical disparity and the stimulus direction by applying a vertical magnification to the image presented to one eye. We used a staircase paradigm to measure whether perceived straight-ahead depended on the amount of vertical magnification in the stimulus. Subjects judged whether a test dot was flashed to either the left or the right side of straight-ahead. We found that perceived straight-ahead did indeed depend on the amount of vertical magnification but only after subjects adapted (for 5 min) to vertical scale (and only in five out of nine subjects). We argue that vertical disparity is a factor in the calibration of the relationship between eye-position signals and perceived direction.

Multifunctional metasurfaces integrating near-field display and 3D holography

2021 ◽  
Author(s):  
Wenjuan Du ◽  
Zhilang Lou ◽  
Xuesong Chen ◽  
Long Chen ◽  
Dongliang Tang
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Optical Field ◽  
Amplitude Control ◽  
3D Images ◽  
Full Wave ◽  
Complex Functions ◽  
Channel Information ◽  
Amplitude Modulator ◽  
Optical Applications

Abstract Metasurfaces have versatile manipulation capabilities in the optical field and provide the possibility of building a compact optical device with various complex functions. They have been regarded as ideal candidates to construct a miniaturized optical system with high density and multi-channel information. In this work, reflective all-metallic multifunctional metasurfaces consisting of aluminum nanorods are designed by simultaneously realizing the near-filed display and three-dimensional (3D) holography. Specifically, in the proposed design, each nanorod acts as a complex amplitude modulator to provide continuous amplitude control and binary phase control. By carefully optimizing the orientations of nanorods, a multifunctional metasurface can be designed to display a near-field grayscale pattern and far-field 3D images simultaneously. Numerical results by a full-wave simulation validate the good performance of the proposed design. The proposed method could provide more degree of freedom to designs of lightweight devices, which could be employed in optical applications, such as the virtual or augmented reality display and anti-counterfeit technology.

A Novel Method for Automated Acquisition of Tilt Series for Electron Tomography Based on Pre-Calibration of the Specimen Stage

2000 ◽  
Vol 6 (S2) ◽  
pp. 1148-1149
Author(s):  
U. Ziese ◽  
A.H. Janssen ◽  
T.P. van der Krift ◽  
A.G. van Balen ◽  
W.J. de Ruijter ◽  
...  
Keyword(s):  
High Resolution ◽  
3D Reconstruction ◽  
Cell Biology ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Imaging Method ◽  
3D Images ◽  
Tilt Series ◽  
3D Information ◽  
Structural Arrangements

Electron tomography is a three-dimensional (3D) imaging method with transmission electron microscopy (TEM) that provides high-resolution 3D images of structural arrangements. Conventional TEM images are in first approximation mere 2D-projections of a 3D sample under investigation. With electron tomographya series of images is acquired of a sample that is tilted over a large angular range (±70°) with small angular tilt increments (so called tilt-series). For the subsequent 3D-reconstruction, the images of the tilt series are aligned relative to each other and the 3D-reconstruction is computed. Electron tomography is the only technique that can provide true 3D information with nm-scale resolution of individual and unique samples. For (cell) biology and material science applications the availability of high-resolution 3D images of structural arrangements within individual samples provides unique architectural information that cannot be obtained otherwise. Routine application of electron tomography will comprise a major revolutionary step forward in the characterization of complex materials and cellular arrangements.

Quantitative Analysis of Soft Soil Microstructure in Unloading Levels

2013 ◽  
Vol 401-403 ◽  
pp. 1529-1533 ◽  
Author(s):  
Qi Zhi Hu ◽  
Jing Xia Wang ◽  
Gao Liang Tao
Keyword(s):  
Quantitative Analysis ◽  
Soft Soil ◽  
Three Dimensional ◽  
Sem Images ◽  
3D Images ◽  
Soil Microstructure ◽  
Transverse Profile ◽  
Pore Area ◽  
Dimensional Simulation ◽  
Pore Number

Quantitative analysis of soft soil microstructure in unloading levels are made by using scanning electron microscope (SEM) images, IPP and PS of image technology ,which includes image segmentation, pore size measuring and counting, three dimensional simulation of soft soil microstructure, etc. The results indicate that, with the increase of unloading grade, pore number and area of big aperture are in a sharp increase, the corresponding porosity also in ascension, so the deformation of the soil is mainly due to the change of pore; compared with the apparent 3d images of soil under the transverse profile in unloading levels. The results also indicate that, with the increase of unloading grade, pore area of cross section are in a increase.

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