Search results for "RECONSTRUCTION"
showing 10 items of 784 documents
Projection-based improvement of 3D reconstructions from motion-impaired dental cone beam CT data.
2019
Purpose Computed tomography (CT) and, in particular, cone beam CT (CBCT) have been increasingly used as a diagnostic tool in recent years. Patient motion during acquisition is common in CBCT due to long scan times. This results in degraded image quality and may potentially increase the number of retakes. Our aim was to develop a marker-free iterative motion correction algorithm that works on the projection images and is suitable for local tomography. Methods We present an iterative motion correction algorithm that allows the patient's motion to be detected and taken into account during reconstruction. The core of our method is a fast GPU-accelerated three-dimensional reconstruction algorith…
Lightfield recording and reconstruction by integral imaging
2011
Integral imaging is a rising 3D imaging technique that can be considered the incoherent version of holography. In integral imaging the multiperspective information of 3D scenes is stored in a 2D picture. Such picture is nothing but a sampling version of the lightfield emitted by the 3D scene. The recorded lightfield can be used for many purposes. One is the display of 3D color scenes to audiences or much more than one person. Other is the 3D display, with full parallax, in personal monitors, like the screen of a Smartphone, a tablet, or the monitor used by a surgeon in an endoscopic operation. Other important types of applications are connected with the topographic reconstruction, slice by …
Use of new technique of image based aimed to perspective return
2014
The diffusion of Image-based 3D modeling techniques, through image-based free, low cost and open source software, have increased drastically in the past few years, especially in Cultural Heritage domain (Architecture, Archeology, Urban planning) [2, 3]. Computer vision techniques use photographs from dataset collection to rapidly build detailed 3D models. The simultaneous applications of different algorithms (MVS), the different techniques of image matching, feature extracting and mesh optimization are inside an active field of research in computer vision. Computer vision techniques - Structure from Motion (SfM)- allow to fulfill detailed 3D models from photos dataset collections. The resul…
Supershape Recovery from 3D Data Sets
2006
In this paper, we apply supershapes and R-functions to surface recovery from 3D data sets. Individual supershapes are separately recovered from a segmented mesh. R-functions are used to perform Boolean operations between the reconstructed parts to obtain a single implicit equation of the reconstructed object that is used to define a global error reconstruction function. We present surface recovery results ranging from single synthetic data to real complex objects involving the composition of several supershapes and holes.
Physico-chemical and mechanical characterization of in-situ forming xyloglucan gels incorporating a growth factor to promote cartilage reconstruction
2016
Abstract The development of growth factors is very promising in the field of tissue regeneration but specifically designed formulations have to be developed in order to enable such new biological entities (NBEs). In particular, the range of therapeutic concentrations is usually very low compared to other active proteins and the confinement in the target site can be of crucial importance. In-situ forming scaffolds are very promising solutions for minimally invasive intervention in cartilage reconstruction and targeting of NBEs. In this work injectable, in-situ forming gels of a temperature responsive partially degalactosylated xyloglucan (Deg-XG) incorporating the growth factor FGF-18 are fo…
A non-parametric Scale-based Corner Detector
2008
This paper introduces a new Harris-affine corner detector algorithm, that does not need parameters to locate corners in images, given an observation scale. Standard detectors require to fine tune the values of parameters which strictly depend on the particular input image. A quantitative comparison between our implementation and a standard Harris-affine implementation provides good results, showing that the proposed methodology is robust and accurate. The benchmark consists of public images used in literature for feature detection.
Reconstruction of full thickness scalp defects after tumour excision in elderly patients: our experience with Integra dermal regeneration template.
2010
Summary Background Scalp reconstruction after wide tumor excision is particularly challenging. Free tissue transfers, local flaps, or skin grafts can be used but present some disadvantages especially with old patients with local advanced cancers, systemic diseases and in patients with a prior history of recurring scalp skin cancers in which the risk of burying a recurring tumor with a flap is likely. The Authors expose their early experience with Integra ® dermal regeneration template for scalp reconstruction after scalp tumor excision. Methods Eight patients with primary or secondary scalp tumor underwent a first surgical procedure under local anaesthesia for tumor removal and Integra ® po…
Three-dimensional polarimetric computational integral imaging
2012
In this paper, we propose a novel 3D polarimetric computational integral imaging system by using polarization diversity of objects under natural illumination conditions. In the system, the measured Stokes polarization parameters are utilized to generate degree of polarization images of a 3D scene. Based on degree of polarization images and original 2D images, we utilize a modified computational reconstruction method to perform 3D polarimetric image reconstruction. The system may be used to detect or classify objects with distinct polarization signatures in 3D space. Experimental results also show the proposed system may mitigate the effect of occlusion in 3D reconstruction.
Head Tracking Three-Dimensional Integral Imaging Display Using Smart Pseudoscopic-to-Orthoscopic Conversion
2016
A novel head tracking three-dimensional (3D) integral imaging display is presented. By means of proper application of the smart pseudoscopic-to-orthoscopic conversion (SPOC) method, our display allows an extended viewing angle accommodated to the viewer's position which is obtained by a head/eye tracking system. Using the SPOC, new sets of elemental images are calculated and adapted to any specific viewing position. Additionally, the crosstalk which is typical in conventional integral imaging, is eliminated for a large viewing angle. By performing the rotation transformation in the simulated display, viewing a 3D scene with head rotation can be realized for robust display. Experimental resu…
Multiple-Planes Pseudoscopic-to-Orthoscopic Conversion for 3D Integral Imaging Display
2015
In this paper, we propose an advanced pseudoscopic-to-orthoscopic conversion method for 3D integral imaging display systems. Compared to previous works, this method can generate more accurate images for orthoscopic 3D display using multiple reference planes and estimated depth information. 3D display results show the superiority of the proposed pseudoscopic-to-orthoscopic conversion method.