Alexander Bornik

Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology

The non-invasive detection and digital documentation of buried archaeological heritage by means of geophysical prospection is increasingly gaining importance in modern field archaeology and archaeological heritage management. It frequently provides the detailed information required for heritage protection or targeted further archaeological research...

– Usually only GPR reflection amplitudes are imaged, while GPR data contain far more information. – Multi-trace GPR coherency visualisations offer new insights into structures otherwise hardly visible. – Image fusing permits the combined display of different GPR data attributes (amplitude and coherency).

Neubauer, W., Bornik, A., Wallner, M. and Verhoeven, G.J.J. (2019), “Novel volume visualisation of GPR data inspired by medical applications”, in Bonsall, J. (Ed.), New global perspectives on archaeological prospection: Proceedings of the 13th International Conference on Archaeological Prospection, 28 August – 1 September 2019, Sligo - Ireland, Arc...

The non-invasive prospection of our archaeological heritage is one of the main tasks of modern archaeology and often provides the necessary bases for further activities, such as special protection or intensified research. Geophysical prospections using ground-penetrating radar (GPR) are an invaluable tool for the non-destructive exploration of arch...

Three-dimensional (3D) crime scene documentation using 3D scanners and medical imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) are increasingly applied in forensic casework. Together with digital photography, these modalities enable comprehensive and non-invasive recording of forensically relevant information r...

Liver segmentation is the first data analysis step in computer-aided planning of liver tumor resections. For clinical applicability, the segmentation approach must be able to cope with the high variation in shape and gray-value appearance of the liver. In this article we present a novel segmentation scheme based on a true 3D segmentation refinement...

The increasing use of CT/MR devices in forensic analysis motivates the need to present forensic findings from different sources in an intuitive reference visualization, with the aim of combining 3D volumetric images along with digital photographs of external findings into a 3D computer graphics model. This model allows a comprehensive presentation...

Integral image data structures are very useful in computer vision applications that involve machine learning approaches based on ensembles of weak learners. The weak learners often are simply several regional sums of intensities subtracted from each other. In this work we present a memory efficient integral volume data structure, that allows reduct...

This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric ob-jects and polyhedral models. Our system is the first hardware acceler-ated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such uni-fied computation was...

An interactive framework prepares raw computed-tomography and magnetic-resonance-imaging scans for courtroom presentations. The framework makes use of combined computer graphics and computer vision techniques to enable a forensic case analysis workflow.

Liver segmentation is an important prerequisite for the assessment of liver cancer treatment options like tumor resection, image-guided radiation therapy (IGRT), radiofrequency ablation, etc. The purpose of this work was to evaluate a new approach for liver segmentation. A graph cuts segmentation method was combined with a three-dimensional virtual...

n this paper, we present a first proof-of-concept for using a mobile Brain-Computer Interface (BCI) coupled to a wearable computer as an ambient input device for a ubiquitous computing service. BCI devices, such as electroencephalogram (EEG) based BCI, can be used as a novel form of human-computer interaction device. A user can log into a nearby co...

A recent trend in medical virtual reality is to include information from multiple sources, especially about physiology, into one model and one single visualization. Computer graphics must therefore deal with a huge amount of information in real time. The latest developments in computer graphics hardware allow not only implementing direct volume ren...

We present a new GPU-based rendering system for ray casting of multiple volumes. Our approach supports a large number of volumes, complex translucent and concave polyhedral objects as well as CSG intersections of volumes and geometry in any combination. The system (including the rasterization stage) is implemented entirely in CUDA, which allows ful...

Segmentation of medical volume data sets (i.e., partitioning images into a set of disjoint regions representing different semantic objects) is an important research topic due to its large number of potential clinical applications. In order to get accepted by physicians and radiologists a generic, interactive 3D segmentation algorithm has to be simp...

This paper presents a comparison study between 10 automatic and six interactive methods for liver segmentation from contrast-enhanced CT images. It is based on results from the "MICCAI 2007 Grand Challenge" workshop, where 16 teams evaluated their algorithms on a common database. A collection of 20 clinical images with reference segmentations was p...

Liver tumors account for a considerable number of deaths every year (World Health Organization, 2004). One of type of primary liver tumors is hepatocellular carcinoma, which arises frequently as a complication of liver cirrhosis. Additionally, almost any tumor can seed metastasis within the liver, colorectal cancer being at the top of the list.

Liver segmentation is an important prerequisite for planning of surgical interventions like liver tumor resections. For clinical applica-bility, the segmentation approach must be able to cope with the high variation in shape and gray-value appearance of the liver. In this pa-per we present a novel segmentation scheme based on a true 3D seg-mentatio...

This paper presents a novel software system called Thekla that fa-cilitates the integration of 2D and 3D user interfaces into hybrid, distributed mixed reality applications. Combining heterogenous display and interaction devices allows mixing and matching of in-teraction styles for a convenient user experience that is often ab-sent from pure virtua...

In liver surgery planning, 2D and desktop-based 3D systems offer surgeons limited assistance. By using VR technology to liberate 3D from 2D input devices such as the mouse and keyboard, this surgery planning system better supports surgeons. User studies show that the system is both effective and easy to use.

This paper presents a novel system for interactive visualization and manipulation of medical datasets for surgery planning based on a hybrid VR / Tablet PC user interface. The goal of the system is to facilitate efficient visual inspection and correction of surface models generated by automated segmentation algorithms based on x-ray computed tomogr...

This paper presents a set of Virtual Reality-based interaction techniques for spatial analysis of medical datasets. Computer-aided medical planning tools often require precise and intuitive interaction for the quantitative inspection and analysis of anatomical and pathological structures. We claim that measurement tasks can be carried out more effi...

This article describes OTQt, an add-on module to the tracking data flow library Open-Tracker. The module converts dedicated tracking data into desktop mouse events and posts these events to Trolltech Qt desktop applications. OTQt addresses a usability problem that may emerge in hybrid 2D/3D AR environments where 2D and 3D scenes are operated with d...

In this paper we present a novel system for segmentation refine-ment, which allows for interactive correction of surface models generated from imperfect automatic segmentations of arbitrary volumetric data. The proposed approach is based on a deformable surface model allowing interactive manipulation with a hybrid user interface consisting of an im...

This paper presents a set of augmented reality (AR) based interaction techniques for spatial analysis of medical datasets. Computer-aided medical planning tools such as our virtual liver surgery planning system require precise and intuitive interaction for the quantitative inspection of anatomical and pathological structures. We argue that AR is a...

Modelling and reconstruction of tubular objects from graph representations is frequently needed in medical visualization. The constructed geometrical models need to be consistent and compact at the same time for interactive applications. In this paper we present a new method for generating compact topologically consistent 2-manifold surfaces of bra...

This paper presents a new approach for constructing a con- sistent (non-manifold) mesh based on non-binary datasets. Mesh gener- ation is the method of choice if a surface is extracted based on labeled volumetric datasets. In most cases, the traditional Marching Cubes al- gorithm or one of its extensions is applied for generating meshes of bi- nary...

Modelling and reconstruction of tubular objects is a known problem in computer graphics. For computer aided surgical planning the constructed geometrical models need to be consistent and compact at the same time, which known approaches cannot guarantee. In this paper we present a new method for generating compact, topologically consistent, 2-manifo...

This paper presents a method for constructing consistent non-manifold meshes of multi-labeled volu- metric datasets. This approach is dieren t to traditional surface reconstruction algorithms which often only support extracting 2-manifold surfaces based on a binary voxel classication. However, in some { especially medical { applications, multi-labe...

BACKGROUND: The preoperative planning of liver resections is commonly based on two-dimensional imaging techniques such as sonography, computed tomography (CT), and magnetic resonance imaging. The operability of liver tumors depends on the three-dimensional relation of the parenchyma to be resected to the intrahepatic vascular structures which defin...

Surgical planning of liver tumor resections requires detailed three-dimensional (3D) understanding of the complex arrangement of vasculature, liver segments and tumors. Knowledge about location and sizes of liver segments is important for choosing an optimal surgical resection approach and predicting postoperative residual liver capacity. The aim o...

Surgical resection has evolved to an accepted and widely-used method for the treatment of liver tumors. In order to elaborate an optimal resection strategy, computer-aided planning tools are required. However, measurements based on 2D cross sectional images are difficult to perform. Moreover, resection planning with current desktopbased systems usi...

Planning of surgical liver tumor resections based on image data from X-ray computed tomography requires correct segmentation of the liver, liver vasculature and pathological structures. Automatic liver segmentation methods frequently fail in cases where the anatomy is degenerated by lesions or other present liver diseases. On the other hand perform...

Quantitative analysis is of major importance for various medical applications, especially for liver surgery planning, where physicians rely on exact volume and distance information for elaborating resection proposals. This paper presents a new approach comprising intuitive measurements by using Augmented Reality facilities. Besides two fast volume...

The quality of a 3D volume visualization heavily depends on a representative transfer function which is responsible for mapping the original density values to color and opacity. Finding a suitable transfer function is often a tedious task if done manually in a trial-and-error fashion by specifying piecewise linear functions for each color and opaci...

Surgical resection of liver tumors requires a detailed three-dimensional understanding of a complex arrangement of vasculature, liver segments and tumors inside the liver. In most cases, surgeons need to develop this understanding by looking at sequences of axial images from modalities like X-ray computed tomography. A system for liver surgery plan...

A system for liver surgery planning is reported that enables physicians to visualize and refine segmented input liver data sets, as well as to simulate and evaluate different resection plans. The system supports surgeons in finding the optimal treatment strategy for each patient and facilitates the data preparation process. Using augmented reality...

We solve the problem of quantitative measuring of image quality, beyond the widely used MSE (mean square error) or even visual comparison. We combine eight feature-based and perceptually-oriented image quality metrics. The need for this comes from virtual archaeology, where various image acquisitions, antialiasing, multiresolution, image reconstruc...

This paper presents an efficient volume measurement method for quantitative assessments within a virtual liver surgery planning system. The measurement is carried out by hardware-accelerated voxelization of surface-based models in order to be applicable for interactive applications. The focus of this paper is the presentation of our voxelization te...

This paper presents a method to automatically calculate texture maps for a given three-dimensional object out of a sequence of images. It is used in our image-based modeling approach after the registration of the images and the geometric modeling is done. We show that the presented method uses the information from all images by implicitly applying...

This paper presents a method to automatically calculate texture maps for a given 3-dimensional object out of a sequence of images. It is used in our image-based modeling approach after the registration of the images and the geometric modeling is done. We show, that the presented method uses the information from all images by implicitly applying a w...

This paper presents a method to automatically calculate texture maps for a given 3D object from a sequence of images. It is used in our image-based modeling approach after the registration of the images and the geometric modeling has been done. We show that the presented method uses the information from all images by implicitly applying a weighting...

By developing a taxonomy of existing systems, libraries and frame-works used for developing Mixed Reality and Ubiquitous Comput-ing environments, it can be seen that little effort has been made to research applications that share the characteristics of these two fields. Solutions have focussed on meeting the needs of each project in turn, rather th...

Augmented Reality (AR) and Virtual Reality (VR) have the po- tential to improve surgical interventions and image-guided therapy by providing clinicians with interactive three-dimensional visual- izations in all phases of treatment. However, experimental AR re- search applications typically focus on a single medical procedure and do not attempt to c...

SUMMARY Future emission regulations and increased customer demands require the utilization of all available tools in developing engines of the next generation. 3D CFD simulation is one of these tools (1). Due to well-advanced and well- developed simulation technology and improved computing power, the generated pack of data becomes complex and diffi...

This paper compares two dierent methods to reconstruct textured models from real images. View Dependent Texture Mapping (VDTM), one of the investigated methods, executes the texturing dur-ing the rendering phase using the real images. In the second method, the multiresolution texture mapping, a texture map is calculated in a preprocessing step. We...