Augmented reality applications become more and more important to enhance our daily life and workflows. The possibility of showing additional virtual content in a camera stream is helpful for many different use cases l...
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Augmented reality applications become more and more important to enhance our daily life and workflows. The possibility of showing additional virtual content in a camera stream is helpful for many different use cases like room planning where such applications can offer a simple and intuitive visualization. However, augmented reality applications can suffer from the interference by real objects that may disrupt the user experience. In recent years, there has been research regarding the removal of real objects from camera streams by applying diminished reality techniques. Current approaches are generally limited to flat objects, video streams with little camera movement, or can only remove objects in front of simple and mostly planar backgrounds. In our approach, we show a robust and efficient way to remove a selected3d object from the camera stream visually. The removal is based on a dense 3dreconstruction of the physical environment stored in a voxel grid that can be created and extended on-the-fly. Hereby, an undesired object can be replaced by a background rendered from the reconstruction allowing for more complex environments than previous approaches. Furthermore, remaining holes by the removal of the object are removed applying an inpainting approach. Finally, we apply color correction to get a seamless transition between the virtual content and the camera image.
This paper presents a research project developed on the archaeological site of Pietrabbondante (Italy) particularly important for its temple-theatre Italic complex. The research entailed not only the massive acquisiti...
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ISBN:
(纸本)9781728102924
This paper presents a research project developed on the archaeological site of Pietrabbondante (Italy) particularly important for its temple-theatre Italic complex. The research entailed not only the massive acquisition of the site through 3d laser scanning and image-based capturing but also the critical study and cataloging of the findings as a premise for the reconstructive hypothesis of the complex. This process of investigation has contributed to enhance the knowledge of the archaeological site, providing support and information to the local administration and helping the local communities to better appreciate the cultural value of the monument.
In recent decades, computer vision and computer graphics especially 3dreconstruction have been a hot area of computer research. As the scenes reconstructed from multi-view images become larger and larger, a single ma...
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ISBN:
(数字)9781728147529
ISBN:
(纸本)9781728147536
In recent decades, computer vision and computer graphics especially 3dreconstruction have been a hot area of computer research. As the scenes reconstructed from multi-view images become larger and larger, a single machine can no longer meet the requirement of the dense point cloudreconstruction in large-scale scene reconstruction. In this paper, a distributed method is proposed to reconstruct the dense point cloud for accurate multi-view reconstruction. First, the initial image set is constructed into a graph, and the graph is divided into several graphs using the improved graph cut algorithm, so the image set will be parted into several small image sets according to the result of the graph cut. Then, the generation and optimization of dense point cloud will be performed on different nodes of the cluster. Finally, the dense point clouds generated on different machines will be merged on the primary node to generate a dense point cloud of the entire scene. Experiments on public large data sets and our own large-scale aerial photography show that the distributed method is fast, robust, and suitable for various large scene areas.
A 3ddose reconstruction coulddetect many errors for IMRT plans, including delivery machine error and suboptimal treatment plans, as well as enhancedvisualization of the beam deviation on volume target. In this stud...
A 3ddose reconstruction coulddetect many errors for IMRT plans, including delivery machine error and suboptimal treatment plans, as well as enhancedvisualization of the beam deviation on volume target. In this study, we aim to develop an in-house software based on MATLAB to enable 3ddose calculation model based on 2d energy fluence data. A homogeneous virtual water phantom, which has a density of 1 g/cm3, was used to test the 3dreconstruction. We reconstructed the field sizes of 4×4, 10×10, and 15×15 cm2 from jaws only collimating to ensure that the algorithm agrees with the small field, standard field, and maximum opening field, in intensity-modulated radiotherapy (IMRT) treatment procedure. The evaluation was done for percentage depth doses (Pdds) and beam profiles. We found that the photon attenuation varies with increasing depth but remains the same after 10 cm depth of water. Moreover, it depends on the flattening filter and jaws design. The Pdd of our algorithm was found to agree with the Monte Carlo (MC) simulation, with the average dose differences 1.07 ± 1.45%, 1.14 ± 3.49%, and 1.11 ± 1.52% for the field sizes of 4×4, 10×10, and 15×15 cm2, respectively. A large error was found in the build-up region, but still within 10%. The dose difference on beam profile was evaluated at zmax equals 1.6, 5, and 10 cm. The highest dose deviation of beam profile to MC simulation was found to be -35.5 ± 9.14% for the field size of 4×4 cm2 at zmax anddecreases with increasing depth and field size of the photon beam.
The preservation, conservation and restoration of historic buildings and monuments is of particular importance for countries, nations and communities. However, there are very often serious debates related to the physi...
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ISBN:
(纸本)9781538670941
The preservation, conservation and restoration of historic buildings and monuments is of particular importance for countries, nations and communities. However, there are very often serious debates related to the physical reconstruction of such objects. In this paper, we present how the application of virtualreconstruction can be helpful in such situations.
In this paper, in connection with the conservation, preservation and restoration of historic monuments, we present some details about the virtualreconstruction of a medieval church.
ISBN:
(纸本)9781538670941
In this paper, in connection with the conservation, preservation and restoration of historic monuments, we present some details about the virtualreconstruction of a medieval church.
We study how mixed-reality (MR) telepresence can enhance long-distance human interaction and how altering three-dimensional (3d) representations of a remote person can be used to modulate stress and anxiety during soc...
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ISBN:
(纸本)9781538692691
We study how mixed-reality (MR) telepresence can enhance long-distance human interaction and how altering three-dimensional (3d) representations of a remote person can be used to modulate stress and anxiety during social interactions. To do so, we developed an MR telepresence system employing commodity depth sensors and Microsoft's Hololens. A textured, polygonal 3d model of a person was reconstructed in real time and transmitted over network for rendering in remote location using Hololens. In this pilot study, we used mock job interview paradigm to induce stress in human-subjects interacting with an interviewer presented as an MR hologram. Participants were exposed to three different types of real-time reconstructedvirtual holograms of the interviewer, a naturalsized3dreconstruction (NR), a miniature 3dreconstruction (SR) and a 2d-display representation (LCd). Participants reported their subjective experience through questionnaires, while their biophysical responses were recorded. We found that the size of 3d representation of a remote interviewer had a significant effect on participants' stress levels and their sense of presence. NR condition induced more stress and presence than SR condition and was significantly different from LCd condition.
In positron emission tomography (PET), decreasing patient injected radiation dose or scan time leads to a reduction in acquisition counts and noisy reconstructed images. Approaches such as post-smoothing (PS) and tota...
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ISBN:
(纸本)9781728141640
In positron emission tomography (PET), decreasing patient injected radiation dose or scan time leads to a reduction in acquisition counts and noisy reconstructed images. Approaches such as post-smoothing (PS) and total variation (TV) denoising can help reduce noise at the cost of resolution or bias, respectively. However, recent advances in convolutional neural networks (CNNs) have lead to promising results in low count PET. Some of these can take advantage of jointly acquireddata from other modalities such as magnetic resonance (MR) imaging. However, there are many considerations when designing an architecture depending on the specific task anddata available. This work compares some of the current state-of-the-art approaches. Results demonstrate that more powerful, complex networks do not necessarily yield better performance. Normalised root mean squared error (NRMSE) is decreased by 85.5% compared to standard maximum likelihood expectation maximisation (MLEM) PET reconstruction by using a 3-layer micro-network on very low (3.01M) count simulation data. This compares to reductions of 80.2% and 85.3% when total variation (TV) edge enhancement and an adversarial discriminator are incorporated into the loss function, respectively. Using both TV and a discriminator term produces a slightly better whole-brain NRMSE reduction of 86.0%, though with a risk of false positive lesions. This indicates that more investigation is required to determine general rules for choosing architectures and hyperparameters for low count PET.
The visualization of tele-operated and autonomous executions in the field becomes difficult if the real environments are located in remote areas or present potential dangers for visualizing clients. This work proposes...
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ISBN:
(数字)9783319952826
ISBN:
(纸本)9783319952826;9783319952819
The visualization of tele-operated and autonomous executions in the field becomes difficult if the real environments are located in remote areas or present potential dangers for visualizing clients. This work proposes an application based on virtual reality to recreate in real time the execution tasks of a UAV, which is operated remotely or autonomously on a real environment. To achieve a third level of immersion, the reconstruction of the real environment where the field tests are executed is considered, offering the possibility of knowing the real scenario where the tests are executed. The consideration of using commercial UAV development kits is taken into account to obtain internal information, as well as to control the drone from client devices. The results presented validate the unification of 3d models and the reconstruction of the environment, as well as the consumption of vehicle information and climate parameters.
We achieve the virtualreconstruction of tomb of LiChongrun who is the Prince of Tang dynasty andvirtual restoration of the frescoes in the tomb by the technology of computer vision andvirtual reality. Our goal is t...
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ISBN:
(纸本)9781538684979
We achieve the virtualreconstruction of tomb of LiChongrun who is the Prince of Tang dynasty andvirtual restoration of the frescoes in the tomb by the technology of computer vision andvirtual reality. Our goal is to solve the problem of Prince Yide tomb's structure recovery and falling mural restoration, and improve the efficiency and effect of digital protection of cultural sites. We utilize high precision photography, digital scanning and3d model reconstruction to provide complete image information for the tombs. Combining sensory interaction, virtual roaming, image animation and other technologies to enhance the performance in virtual space, we let users have fully immersive experience and offer users a platform to learn the tombs of Tang dynasty and enjoy the beauty of tomb mural. By this means, we can maximize the recording anddissemination of precious historical and cultural information contained in the cultural heritage itself.
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