Vehicle Spatial Distribution and 3D Trajectory Extraction Algorithm in a Cross-Camera Traffic Scene

The three-dimensional trajectory data of vehicles have important practical meaning for traffic behavior analysis. To solve the problems of narrow visual angle in single-camera scenes and lack of continuous trajectories in 3D space by current cross-camera trajectory extraction methods, we propose an algorithm of vehicle spatial distribution and 3D trajectory extraction in this paper. First, a panoramic image of a road with spatial information is generated based on camera calibration, which is used to convert cross-camera perspectives into 3D physical space. Then, we choose YOLOv4 to obtain 2D bounding boxes of vehicles in cross-camera scenes. Based on the above information, 3D bounding boxes around vehicles are built with geometric constraints which are used to obtain projection centroids of vehicles. Finally, by calculating the spatial distribution of projection centroids in the panoramic image, 3D trajectories of vehicles are extracted. The experimental results indicate that our algorithm can effectively complete vehicle spatial distribution and 3D trajectory extraction in various traffic scenes, which outperforms other comparison algorithms.

Download Full-text

A virtual diorama. Mapping archives in situ at places of cultural significance

Nordisk Museologi ◽

10.5617/nm.6343 ◽

1970 ◽

pp. 22-36

Author(s):

Jonathan Westin ◽

Gunnar Almevik

Keyword(s):

Spatial Information ◽

Three Dimensional ◽

Physical Space ◽

Cultural Significance ◽

Dimensional Reconstruction ◽

Historical Photographs ◽

New Applications ◽

Archive Material

Using the wooden church of Södra Råda as a case study, this article concerns new applications of technology to contextualise and activate archive material in situ at places of cultural significance. Using a combination of augmented reality and virtual reality, we describe a process of turning historical photographs and two-dimensional reconstruction drawings into three-dimensional virtual models that can be lined up to a physical space. The leading questions for our investigation concern how archive material can be contextualised, and how the result may be made accessible in situ and contribute to place development. The result of this research suggests possibilities for using historical photographs to faithfully reconstruct lost historical spaces as three-dimensional surfaces that contextualise documentation and offer spatial information.

Download Full-text

Spatial Distribution of Dialysate in Patients and its Implications to Intradialysate Diffusion

Peritoneal Dialysis International ◽

10.1177/089686080202200609 ◽

2002 ◽

Vol 22 (6) ◽

pp. 698-704 ◽

Cited By ~ 2

Author(s):

Brian A. Hills ◽

Seamus Birch ◽

John R. Burke ◽

Anthony C. LaMont

Keyword(s):

Spatial Distribution ◽

Peritoneal Dialysis ◽

Spatial Information ◽

Three Dimensional ◽

Bulk Diffusion ◽

Ct Scanning ◽

Effective Area ◽

Pelvic Cavity ◽

Ct Scanner ◽

Computed Tomographic

Objective To visualize and quantify the spatial distribution of dialysate in patients on continuous ambulatory peritoneal dialysis (CAPD) and, hence, estimate diffusion times for fluid “pockets” wherever intradialysate concentration gradients may not be dissipated by convective currents. Design Contrast medium was added to the dialysate of three supine CAPD patients before an exchange prior to computed tomographic (CT) scanning. Spatial information in the CT scanner was then downloaded to other computers and processed to produce impressive three-dimensional models of dialysate distribution using “wire frame technology.” Results Models differed between patients but all demonstrated pooling of dialysate in the paracolic gutters, subphrenic space, and, especially, in the pelvic cavity. Some pockets of fluid were almost isolated. Quantitatively, the models can account for over 80% of the volume of the exchange (2.5 L), displaying an effective area of contact of 913 – 1450 cm2 between parietal peritoneum and dialysate. This amounts to only 11% – 21% of the anatomic area, again emphasizing the uneven distribution of dialysate. Ignoring very thin (< 0.1 mm) films of dialysate, the bulk (80%) had mean thicknesses ranging from 1.6 to 1.9 cm. Transcendental equations for bulk diffusion were then applied to these findings to determine a theoretical time for urea of about 2 – 3 hours to half-saturation, or 5 – 7 hours to 80% saturation, in the absence of convective currents. Conclusions The distribution of dialysate within the peritoneal cavity is very uneven, resulting in long diffusion times in fluid pockets wherever convective currents may be minimal. Hence, intradialysate diffusion should not be ignored when modeling peritoneal dialysis.

Download Full-text

Snake-Based Model for Automatic Roof Boundary Extraction in the Object Space Integrating a High-Resolution Aerial Images Stereo Pair and 3D Roof Models

Remote Sensing ◽

10.3390/rs13081429 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1429

Author(s):

Michelle S. Y. Ywata ◽

Aluir P. Dal Poz ◽

Milton H. Shimabukuro ◽

Henrique C. de Oliveira

Keyword(s):

High Resolution ◽

Spatial Information ◽

Contextual Information ◽

Three Dimensional ◽

Extraction Methods ◽

Aerial Images ◽

Stereo Pair ◽

Boundary Extraction ◽

Building Roof ◽

Object Space

The accelerated urban development over the last decades has made it necessary to update spatial information rapidly and constantly. Therefore, cities’ three-dimensional models have been widely used as a study base for various urban problems. However, although many efforts have been made to develop new building extraction methods, reliable and automatic extraction is still a major challenge for the remote sensing and computer vision communities, mainly due to the complexity and variability of urban scenes. This paper presents a method to extract building roof boundaries in the object space by integrating a high-resolution aerial images stereo pair, three-dimensional roof models reconstructed from light detection and ranging (LiDAR) data, and contextual information of the scenes involved. The proposed method focuses on overcoming three types of common problems that can disturb the automatic roof extraction in the urban environment: perspective occlusions caused by high buildings, occlusions caused by vegetation covering the roof, and shadows that are adjacent to the roofs, which can be misinterpreted as roof edges. For this, an improved Snake-based mathematical model is developed considering the radiometric and geometric properties of roofs to represent the roof boundary in the image space. A new approach for calculating the corner response and a shadow compensation factor was added to the model. The created model is then adapted to represent the boundaries in the object space considering a stereo pair of aerial images. Finally, the optimal polyline, representing a selected roof boundary, is obtained by optimizing the proposed Snake-based model using a dynamic programming (DP) approach considering the contextual information of the scene. The results showed that the proposed method works properly in boundary extraction of roofs with occlusion and shadows areas, presenting completeness and correctness average values above 90%, RMSE average values below 0.5 m for E and N components, and below 1 m for H component.

Download Full-text

H-plane horn antenna with enhanced directivity using conformal transformation optics

Scientific Reports ◽

10.1038/s41598-021-93812-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hossein Eskandari ◽

Juan Luis Albadalejo-Lijarcio ◽

Oskar Zetterstrom ◽

Tomáš Tyc ◽

Oscar Quevedo-Teruel

Keyword(s):

Conformal Transformation ◽

Phase Error ◽

Three Dimensional ◽

Physical Space ◽

Horn Antenna ◽

High Gain ◽

Transformation Optics ◽

Graded Index ◽

Low Profile ◽

Dielectric Lens

AbstractConformal transformation optics is employed to enhance an H-plane horn’s directivity by designing a graded-index all-dielectric lens. The transformation is applied so that the phase error at the aperture is gradually eliminated inside the lens, leading to a low-profile high-gain lens antenna. The physical space shape is modified such that singular index values are avoided, and the optical path inside the lens is rescaled to eliminate superluminal regions. A prototype of the lens is fabricated using three-dimensional printing. The measurement results show that the realized gain of an H-plane horn antenna can be improved by 1.5–2.4 dB compared to a reference H-plane horn.

Download Full-text

Hanging Textiles’ Influence on the Beauty of Indoor Space Decoration

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.332-334.539 ◽

2011 ◽

Vol 332-334 ◽

pp. 539-544

Author(s):

Xiao Dong Liu ◽

Xin Qun Feng ◽

Dong Yang

Keyword(s):

Three Dimensional ◽

Physical Space ◽

Indoor Space ◽

Aesthetic Appeal ◽

Works Of Art

When room space extends from a simple three-dimensional physical space to a four-dimensional spiritual space, when people begin to rise aesthetic appeal to a higher level and emphasize harmony with the environment, the textile works of art at this time were all considered to play one of the most important evolutional roles. Hanging textiles which featured multi-functional made themselves irreplaceable contents in indoor space. From the application and development view of hanging textiles, the article emphasizes on the decorative function and application strategies to look forward to continuously improvement of hanging textiles’ application and design levels in indoor space.

Download Full-text

Estimation of 6D Object Pose Using a 2D Bounding Box

Sensors ◽

10.3390/s21092939 ◽

2021 ◽

Vol 21 (9) ◽

pp. 2939

Author(s):

Yong Hong ◽

Jin Liu ◽

Zahid Jahangir ◽

Sheng He ◽

Qing Zhang

Keyword(s):

Neural Network ◽

Loss Function ◽

Three Dimensional ◽

Unit Vector ◽

Prediction Algorithm ◽

Computational Time ◽

Bounding Box ◽

Dimensional Unit ◽

Bounding Boxes ◽

Rgb Image

This paper provides an efficient way of addressing the problem of detecting or estimating the 6-Dimensional (6D) pose of objects from an RGB image. A quaternion is used to define an object′s three-dimensional pose, but the pose represented by q and the pose represented by -q are equivalent, and the L2 loss between them is very large. Therefore, we define a new quaternion pose loss function to solve this problem. Based on this, we designed a new convolutional neural network named Q-Net to estimate an object’s pose. Considering that the quaternion′s output is a unit vector, a normalization layer is added in Q-Net to hold the output of pose on a four-dimensional unit sphere. We propose a new algorithm, called the Bounding Box Equation, to obtain 3D translation quickly and effectively from 2D bounding boxes. The algorithm uses an entirely new way of assessing the 3D rotation (R) and 3D translation rotation (t) in only one RGB image. This method can upgrade any traditional 2D-box prediction algorithm to a 3D prediction model. We evaluated our model using the LineMod dataset, and experiments have shown that our methodology is more acceptable and efficient in terms of L2 loss and computational time.

Download Full-text

Virtual Archaeology of Death and Burial: A Procedure for Integrating 3D Visualization and Analysis in Archaeothanatology

Open Archaeology ◽

10.1515/opar-2020-0152 ◽

2021 ◽

Vol 7 (1) ◽

pp. 540-555

Author(s):

Hayley L. Mickleburgh ◽

Liv Nilsson Stutz ◽

Harry Fokkens

Keyword(s):

Spatial Information ◽

3D Visualization ◽

Rapid Development ◽

Three Dimensional ◽

3D Models ◽

The Body ◽

Test Case ◽

Archaeology Of Death ◽

Human Burials ◽

3D Information

Abstract The reconstruction of past mortuary rituals and practices increasingly incorporates analysis of the taphonomic history of the grave and buried body, using the framework provided by archaeothanatology. Archaeothanatological analysis relies on interpretation of the three-dimensional (3D) relationship of bones within the grave and traditionally depends on elaborate written descriptions and two-dimensional (2D) images of the remains during excavation to capture this spatial information. With the rapid development of inexpensive 3D tools, digital replicas (3D models) are now commonly available to preserve 3D information on human burials during excavation. A procedure developed using a test case to enhance archaeothanatological analysis and improve post-excavation analysis of human burials is described. Beyond preservation of static spatial information, 3D visualization techniques can be used in archaeothanatology to reconstruct the spatial displacement of bones over time, from deposition of the body to excavation of the skeletonized remains. The purpose of the procedure is to produce 3D simulations to visualize and test archaeothanatological hypotheses, thereby augmenting traditional archaeothanatological analysis. We illustrate our approach with the reconstruction of mortuary practices and burial taphonomy of a Bell Beaker burial from the site of Oostwoud-Tuithoorn, West-Frisia, the Netherlands. This case study was selected as the test case because of its relatively complete context information. The test case shows the potential for application of the procedure to older 2D field documentation, even when the amount and detail of documentation is less than ideal.

Download Full-text

The Role of Spatio-Temporal Information to Govern the COVID-19 Pandemic: A European Perspective

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10030166 ◽

2021 ◽

Vol 10 (3) ◽

pp. 166

Author(s):

Hartmut Müller ◽

Marije Louwsma

Keyword(s):

European Union ◽

Spatial Distribution ◽

Spatial Information ◽

National Level ◽

Temporal Information ◽

The European Union ◽

Member States ◽

Heavy Burden ◽

Spatio Temporal

The Covid-19 pandemic put a heavy burden on member states in the European Union. To govern the pandemic, having access to reliable geo-information is key for monitoring the spatial distribution of the outbreak over time. This study aims to analyze the role of spatio-temporal information in governing the pandemic in the European Union and its member states. The European Nomenclature of Territorial Units for Statistics (NUTS) system and selected national dashboards from member states were assessed to analyze which spatio-temporal information was used, how the information was visualized and whether this changed over the course of the pandemic. Initially, member states focused on their own jurisdiction by creating national dashboards to monitor the pandemic. Information between member states was not aligned. Producing reliable data and timeliness reporting was problematic, just like selecting indictors to monitor the spatial distribution and intensity of the outbreak. Over the course of the pandemic, with more knowledge about the virus and its characteristics, interventions of member states to govern the outbreak were better aligned at the European level. However, further integration and alignment of public health data, statistical data and spatio-temporal data could provide even better information for governments and actors involved in managing the outbreak, both at national and supra-national level. The Infrastructure for Spatial Information in Europe (INSPIRE) initiative and the NUTS system provide a framework to guide future integration and extension of existing systems.

Download Full-text