Martin Eisemann

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38ranked-venue papers
4as first author
12since 2021 · last 2025
—ORCID · conflict

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Graphics, computer vision, multimedia, augmented reality and games · 35 · 4 first-author · 10 since 2021Human-computer interaction and ubiquitous computing · 6 · 2 first-author · 2 since 2021Artificial intelligence and machine learning · 2 · 1 since 2021Security and privacy · 1 · 1 since 2021
YearPublicationVenuePosition
2025 INPC: Implicit Neural Point Clouds for Radiance Field Rendering
abstract
We introduce a new approach for reconstruction and novel view synthesis of unbounded real-world scenes. In contrast to previous methods using either volumetric fields, grid-based models, or discrete point cloud proxies, we pro-pose a hybrid scene representation, which implicitly encodes the geometry in a continuous octree-based probability field and view-dependent appearance in a multi-resolution hash grid. This allows for extraction of arbitrary explicit point clouds, which can be rendered using rasterization. In doing so, we combine the benefits of both worlds and retain favorable behavior during optimization: Our novel implicit point cloud representation and differentiable bilinear rasterizer enable fast rendering while preserving the fine geometric detail captured by volumetric neural fields. Furthermore, this representation does not depend on priors like structure-from-motion point clouds. Our method achieves state-of-the-art image quality on common benchmarks. Furthermore, we achieve fast inference at interactive frame rates, and can convert our trained model into a large, explicit point cloud to further enhance performance.
Florian Hahlbohm, Linus Franke, Moritz Kappel, Susana Castillo 0001, Martin Eisemann, Marc Stamminger, Marcus A. Magnor
3DV5
2025 Seeing Through: Analyzing and Attacking Virtual Backgrounds in Video Calls
Felix Weißberg, Jan Malte Hilgefort, Steve Grogorick, Daniel Arp, Thorsten Eisenhofer, Martin Eisemann, Konrad Rieck
USENIX Security Symposium6
2025 Real-Time Rendering Framework for Holography
abstract
Abstract With the advent of holographic near‐eye displays, the need for rendering algorithms that output holograms instead of color images emerged. These holograms usually encode phase maps that alter the phase of coherent light sources such that images result from diffraction effects. While common approaches rely on translating the output of traditional rendering systems to holograms in a post processing step, we instead developed a rendering system that can directly output a phase map to a Spatial Light Modulator (SLM). Our hardware‐ray‐traced sparse point distribution, and depth mapping enable rapid hologram generation, allowing for high‐quality time‐multiplexed holography for real‐time content. Additionally, our system is compatible with foveated rendering which enables further performance optimizations.
Sascha Fricke, Susana Castillo 0001, Martin Eisemann, Marcus A. Magnor
Comput. Graph. Forum3
2025 Axis-Normalized Ray-Box Intersection
abstract
Abstract Ray‐axis aligned bounding box intersection tests play a crucial role in the runtime performance of many rendering applications, driven not by complexity but mainly by the volume of tests required. While existing solutions were believed to be pretty much optimal in terms of runtime on current hardware, our paper introduces a new intersection test requiring fewer arithmetic operations compared to all previous methods. By transforming the ray we eliminate the need for one third of the traditional bounding‐slab tests and achieve a speed enhancement of approximately 13.8% or 10.9%, depending on the compiler. We present detailed runtime analyses in various scenarios.
Fabian Friederichs, Carsten Benthin, Steve Grogorick, Elmar Eisemann, Marcus A. Magnor, Martin Eisemann
Comput. Graph. Forum6
2025 Efficient Perspective-Correct 3D Gaussian Splatting Using Hybrid Transparency
abstract
Abstract 3D Gaussian Splats (3DGS) have proven a versatile rendering primitive, both for inverse rendering as well as real‐time exploration of scenes. In these applications, coherence across camera frames and multiple views is crucial, be it for robust convergence of a scene reconstruction or for artifact‐free fly‐throughs. Recent work started mitigating artifacts that break multi‐view coherence, including popping artifacts due to inconsistent transparency sorting and perspective‐correct outlines of (2D) splats. At the same time, real‐time requirements forced such implementations to accept compromises in how transparency of large assemblies of 3D Gaussians is resolved, in turn breaking coherence in other ways. In our work, we aim at achieving maximum coherence, by rendering fully perspective‐correct 3D Gaussians while using a high‐quality approximation of accurate blending, hybrid transparency, on a per‐pixel level, in order to retain real‐time frame rates. Our fast and perspectively accurate approach for evaluation of 3D Gaussians does not require matrix inversions, thereby ensuring numerical stability and eliminating the need for special handling of degenerate splats, and the hybrid transparency formulation for blending maintains similar quality as fully resolved per‐pixel transparencies at a fraction of the rendering costs. We further show that each of these two components can be independently integrated into Gaussian splatting systems. In combination, they achieve up to 2× higher frame rates, 2× faster optimization, and equal or better image quality with fewer rendering artifacts compared to traditional 3DGS on common benchmarks.
Florian Hahlbohm, Fabian Friederichs, Tim Weyrich, Linus Franke, Moritz Kappel, Susana Castillo 0001, Marc Stamminger, Martin Eisemann, Marcus A. Magnor
Comput. Graph. Forum8
2025 D-NPC: Dynamic Neural Point Clouds for Non-Rigid View Synthesis from Monocular Video
abstract
Abstract Dynamic reconstruction and spatiotemporal novel‐view synthesis of non‐rigidly deforming scenes recently gained increased attention. While existing work achieves impressive quality and performance on multi‐view or teleporting camera setups, most methods fail to efficiently and faithfully recover motion and appearance from casual monocular captures. This paper contributes to the field by introducing a new method for dynamic novel view synthesis from monocular video, such as casual smartphone captures. Our approach represents the scene as a dynamic neural point cloud, an implicit time‐conditioned point distribution that encodes local geometry and appearance in separate hash‐encoded neural feature grids for static and dynamic regions. By sampling a discrete point cloud from our model, we can efficiently render high‐quality novel views using a fast differentiable rasterizer and neural rendering network. Similar to recent work, we leverage advances in neural scene analysis by incorporating data‐driven priors like monocular depth estimation and object segmentation to resolve motion and depth ambiguities originating from the monocular captures. In addition to guiding the optimization process, we show that these priors can be exploited to explicitly initialize our scene representation to drastically improve optimization speed and final image quality. As evidenced by our experimental evaluation, our dynamic point cloud model not only enables fast optimization and real‐time frame rates for interactive applications, but also achieves competitive image quality on monocular benchmark sequences. Our code and data are available online https://moritzkappel.github.io/projects/dnpc/ .
Moritz Kappel, Florian Hahlbohm, Timon Scholz, Susana Castillo 0001, Christian Theobalt, Martin Eisemann, Vladislav Golyanik, Marcus A. Magnor
Comput. Graph. Forum6
2025 SPaGS: Fast and Accurate 3D Gaussian Splatting for Spherical Panoramas
abstract
Abstract In this paper we propose SPaGS, a high‐quality, real‐time free‐viewpoint rendering approach from 360‐degree panoramic images. While existing methods building on Neural Radiance Fields or 3D Gaussian Splatting have difficulties to achieve real‐time frame rates and high‐quality results at the same time, SPaGS combines the advantages of an explicit 3D Gaussian‐based scene representation and ray casting‐based rendering to attain fast and accurate results. Central to our new approach is the exact calculation of axis‐aligned bounding boxes for spherical images that significantly accelerates omnidirectional ray casting of 3D Gaussians. We also present a new dataset consisting of ten real‐world scenes recorded with a drone that incorporates both calibrated 360‐degree panoramic images as well as perspective images captured simultaneously, i.e., with the same flight trajectory. Our evaluation on this new dataset as well as established benchmarks demonstrates that SPaGS excels over state‐of‐the‐art methods in terms of both rendering quality and speed.
Florian Hahlbohm, Timon Scholz, Martin Eisemann, Jan-Philipp Tauscher, Marcus A. Magnor
Comput. Graph. Forum4
2025 Virtual and Traditional Memory Palaces in Recall with ADHD
abstract
Several studies have examined the potential of immersive technologies, such as Virtual Reality (VR), to enhance the effectiveness of memorization. However, existing research has not specifically focused on individuals with Attention Deficit Hyperactivity Disorder (ADHD), and only a limited number of studies have examined the effectiveness of Memory Palace (MP) as a memorization aid for this population, who often experience working memory impairments. To address this gap, we recruited participants with an official diagnosis of ADHD and conducted an experiment in which we investigated the impact of both the Traditional MP technique and a VR version to assess their impact on a memorization task. Our findings indicate that the effectiveness of a VR-based MP might be influenced by prior experience with VR systems, the level of familiarity with the virtual environment, and the MP technique. Nevertheless, our results demonstrate that the MP technique has the potential to enhance recall performance in individuals diagnosed with ADHD.
Anika Jewst, Susana Castillo 0001, Marcus A. Magnor, Martin Eisemann, Dagmar Meyer
ACM Trans. Appl. Percept.4
2024 Measuring Velocity Perception Regarding Stimulus Eccentricity
abstract
A major factor resulting in cybersickness is the feeling of self-motion experienced when viewing a moving scene in Virtual Reality (VR). Current research indicates that this effect is largely created by motion in the periphery. To discover why this is the case, we investigate the influence of temporal frequency and eccentricity of a stimulus on the magnitude of perceived velocity in the periphery. Based on the perception of two-dimensional stimuli on a wide field-of-view display, we build a model to predict the scaling factor by which the perceived velocity of visual patterns deviates from the physical velocity. Further, our exploratory findings indicate no impact of gaze type on the results, suggesting our model works for both fixation and smooth pursuit scenarios. In an additional pilot study in Virtual Reality (VR), we test the accuracy of the model to predict unnoticeable object motion adaptation in 3D virtual worlds and find positive indications for a similar effect.
Timon Scholz, Colin Groth, Susana Castillo 0001, Martin Eisemann, Marcus A. Magnor
SAP4
2024 Cybersickness Reduction via Gaze-Contingent Image Deformation
abstract
Virtual reality has ushered in a revolutionary era of immersive content perception. However, a persistent challenge in dynamic environments is the occurrence of cybersickness arising from a conflict between visual and vestibular cues. Prior techniques have demonstrated that limiting illusory self-motion, so-called vection, by blurring the peripheral part of images, introducing tunnel vision, or altering the camera path can effectively reduce the problem. Unfortunately, these methods often alter the user's experience with visible changes to the content. In this paper, we propose a new technique for reducing vection and combating cybersickness by subtly lowering the screen-space speed of objects in the user's peripheral vision. The method is motivated by our hypothesis that small modifications to the objects' velocity in the periphery and geometrical distortions in the peripheral vision can remain unnoticeable yet lead to reduced vection. This paper describes the experiments supporting this hypothesis and derives its limits. Furthermore, we present a method that exploits these findings by introducing subtle, screen-space geometrical distortions to animation frames to counteract the motion contributing to vection. We implement the method as a realtime post-processing step that can be integrated into existing rendering frameworks. The final validation of the technique and comparison to an alternative approach confirms its effectiveness in reducing cybersickness.
Colin Groth, Marcus A. Magnor, Steve Grogorick, Martin Eisemann, Piotr Didyk
ACM Trans. Graph.4
2023 Immersive Free-Viewpoint Panorama Rendering from Omnidirectional Stereo Video
abstract
Abstract In this paper, we tackle the challenging problem of rendering real‐world 360° panorama videos that support full 6 degrees‐of‐freedom (DoF) head motion from a prerecorded omnidirectional stereo (ODS) video. In contrast to recent approaches that create novel views for individual panorama frames, we introduce a video‐specific temporally‐consistent multi‐sphere image (MSI) scene representation. Given a conventional ODS video, we first extract information by estimating framewise descriptive feature maps. Then, we optimize the global MSI model using theory from recent research on neural radiance fields. Instead of a continuous scene function, this multi‐sphere image (MSI) representation depicts colour and density information only for a discrete set of concentric spheres. To further improve the temporal consistency of our results, we apply an ancillary refinement step which optimizes the temporal coherency between successive video frames. Direct comparisons to recent baseline approaches show that our global MSI optimization yields superior performance in terms of visual quality. Our code and data will be made publicly available.
Moritz Mühlhausen, Moritz Kappel, Marc Kassubeck, Leslie Wöhler, Steve Grogorick, Susana Castillo 0001, Martin Eisemann, Marcus A. Magnor
Comput. Graph. Forum7
2021 Layered Weighted Blended Order-Independent Transparency
abstract
Our approach improves the accuracy of weighted blended orderindependent transparency, while remaining efficient and easy to implement. We extend the original algorithm to a layer-based approach, where the content of each layer is blended independently before compositing them globally. Hereby, we achieve a partial ordering but avoid explicit sorting of all elements. To ensure smooth transitions across layers, we introduce a new weighting function. Additionally, we propose several optimizations and demonstrate the method's effectiveness on various challenging scenes in terms of geometricand depth complexity. We achieve an error reduction more than an order of magnitude on average compared to weighted blended order-independent transparency for our test scenes.
Fabian Friederichs, Martin Eisemann, Elmar Eisemann
Graphics Interface2
2020 Next Event Estimation++: Visibility Mapping for Efficient Light Transport Simulation
abstract
Abstract Monte‐Carlo rendering requires determining the visibility between scene points as the most common and compute intense operation to establish paths between camera and light source. Unfortunately, many tests reveal occlusions and the corresponding paths do not contribute to the final image. In this work, we present next event estimation++ (NEE++): a visibility mapping technique to perform visibility tests in a more informed way by caching voxel to voxel visibility probabilities. We show two scenarios: Russian roulette style rejection of visibility tests and direct importance sampling of the visibility. We show applications to next event estimation and light sampling in a uni‐directional path tracer, and light‐subpath sampling in Bi‐Directional Path Tracing. The technique is simple to implement, easy to add to existing rendering systems, and comes at almost no cost, as the required information can be directly extracted from the rendering process itself. It discards up to 80% of visibility tests on average, while reducing variance by ∼20% compared to other state‐of‐the‐art light sampling techniques with the same number of samples. It gracefully handles complex scenes with efficiency similar to Metropolis light transport techniques but with a more uniform convergence.
Jerry Jinfeng Guo, Martin Eisemann, Elmar Eisemann
Comput. Graph. Forum2
2019 Applying Visual Analytics to Physically Based Rendering
abstract
Abstract Physically based rendering is a well‐understood technique to produce realistic‐looking images. However, different algorithms exist for efficiency reasons, which work well in certain cases but fail or produce rendering artefacts in others. Few tools allow a user to gain insight into the algorithmic processes. In this work, we present such a tool, which combines techniques from information visualization and visual analytics with physically based rendering. It consists of an interactive parallel coordinates plot, with a built‐in sampling‐based data reduction technique to visualize the attributes associated with each light sample. Two‐dimensional (2D) and three‐dimensional (3D) heat maps depict any desired property of the rendering process. An interactively rendered 3D view of the scene displays animated light paths based on the user's selection to gain further insight into the rendering process. The provided interactivity enables the user to guide the rendering process for more efficiency. To show its usefulness, we present several applications based on our tool. This includes differential light transport visualization to optimize light setup in a scene, finding the causes of and resolving rendering artefacts, such as fireflies, as well as a path length contribution histogram to evaluate the efficiency of different Monte Carlo estimators.
Gerard Simons, Sebastian Herholz, Victor Petitjean, Tobias Rapp, Marco Ament, Hendrik P. A. Lensch, Carsten Dachsbacher, Martin Eisemann, Elmar Eisemann
Comput. Graph. Forum8
2019 Relaxing Dense Scatter Plots with Pixel-Based Mappings
abstract
Scatter plots are the most commonly employed technique for the visualization of bivariate data. Despite their versatility and expressiveness in showing data aspects, such as clusters, correlations, and outliers, scatter plots face a main problem. For large and dense data, the representation suffers from clutter due to overplotting. This is often partially solved with the use of density plots. Yet, data overlap may occur in certain regions of a scatter or density plot, while other regions may be partially, or even completely empty. Adequate pixel-based techniques can be employed for effectively filling the plotting space, giving an additional notion of the numerosity of data motifs or clusters. We propose the Pixel-Relaxed Scatter Plots, a new and simple variant, to improve the display of dense scatter plots, using pixel-based, space-filling mappings. Our Pixel-Relaxed Scatter Plots make better use of the plotting canvas, while avoiding data overplotting, and optimizing space coverage and insight in the presence and size of data motifs. We have employed different methods to map scatter plot points to pixels and to visually present this mapping. We demonstrate our approach on several synthetic and realistic datasets, and we discuss the suitability of our technique for different tasks. Our conducted user evaluation shows that our Pixel-Relaxed Scatter Plots can be a useful enhancement to traditional scatter plots.
Renata G. Raidou, M. Eduard Gröller, Martin Eisemann
IEEE Trans. Vis. Comput. Graph.3
2017 Split-Depth Image Generation and Optimization
abstract
Abstract Split‐depth images use an optical illusion, which can enhance the 3D impression of a 2D animation. In split‐depth images (also often called split‐depth GIFs due to the commonly used file format), static virtual occluders inform of vertical or horizontal bars are added to a video clip, which leads to occlusions that are interpreted by the observer as a depth cue. In this paper, we study different factors that contribute to the illusion and propose a solution to generate split‐depth images for a given RGB + depth image sequence. The presented solution builds upon a motion summarization of the object of interest (OOI) through space and time. It allows us to formulate the bar positioning as an energy‐minimization problem, which we solve efficiently. We take a variety of important features into account, such as the changes of the 3D effect due to changes in the motion topology, occlusion, the proximity of bars or the OOI, and scene saliency. We conducted a number of psycho‐visual experiments to derive an appropriate energy formulation. Our method helps in finding optimal positions for the bars and, thus, improves the 3D perception of the original animation. We demonstrate the effectiveness of our approach on a variety of examples. Our study with novice users shows that our approach allows them to quickly create satisfying results even for complex animations.
Jingtang Liao, Martin Eisemann, Elmar Eisemann
Comput. Graph. Forum2
2017 Perception-driven Accelerated Rendering
abstract
Advances in computer graphics enable us to create digital images of astonishing complexity and realism. However, processing resources are still a limiting factor. Hence, many costly but desirable aspects of realism are often not accounted for, including global illumination, accurate depth of field and motion blur, spectral effects, etc. especially in real-time rendering. At the same time, there is a strong trend towards more pixels per display due to larger displays, higher pixel densities or larger fields of view. Further observable trends in current display technology include more bits per pixel (high dynamic range, wider color gamut/fidelity), increasing refresh rates (better motion depiction), and an increasing number of displayed views per pixel (stereo, multi-view, all the way to holographic or lightfield displays). These developments cause significant unsolved technical challenges due to aspects such as limited compute power and bandwidth. Fortunately, the human visual system has certain limitations, which mean that providing the highest possible visual quality is not always necessary. In this report, we present the key research and models that exploit the limitations of perception to tackle visual quality and workload alike. Moreover, we present the open problems and promising future research targeting the question of how we can minimize the effort to compute and display only the necessary pixels while still offering a user full visual experience.
Martin Weier, Michael Stengel, Thorsten Roth, Piotr Didyk, Elmar Eisemann, Martin Eisemann, Steve Grogorick, André Hinkenjann, Ernst Kruijff, Marcus A. Magnor, Karol Myszkowski, Philipp Slusallek
Comput. Graph. Forum6
2017 Efficient Stochastic Rendering of Static and Animated Volumes Using Visibility Sweeps
abstract
Stochastically solving the rendering integral (particularly visibility) is the de-facto standard for physically-based light transport but it is computationally expensive, especially when displaying heterogeneous volumetric data. In this work, we present efficient techniques to speed-up the rendering process via a novel visibility-estimation method in concert with an unbiased importance sampling (involving environmental lighting and visibility inside the volume), filtering, and update techniques for both static and animated scenes. Our major contributions include a progressive estimate of partial occlusions based on a fast sweeping-plane algorithm. These occlusions are stored in an octahedral representation, which can be conveniently transformed into a quadtree-based hierarchy suited for a joint importance sampling. Further, we propose sweep-space filtering, which suppresses the occurrence of fireflies and investigate different update schemes for animated scenes. Our technique is unbiased, requires little precomputation, is highly parallelizable, and is applicable to a various volume data sets, dynamic transfer functions, animated volumes and changing environmental lighting.
Philipp von Radziewsky, Thomas Kroes, Martin Eisemann, Elmar Eisemann
IEEE Trans. Vis. Comput. Graph.3
2016 Adaptive Image-Space Sampling for Gaze-Contingent Real-time Rendering
abstract
With ever-increasing display resolution for wide field-of-view displays—such as head-mounted displays or 8k projectors—shading has become the major computational cost in rasterization. To reduce computational effort, we propose an algorithm that only shades visible features of the image while cost-effectively interpolating the remaining features without affecting perceived quality. In contrast to previous approaches we do not only simulate acuity falloff but also introduce a sampling scheme that incorporates multiple aspects of the human visual system: acuity, eye motion, contrast (stemming from geometry, material or lighting properties), and brightness adaptation. Our sampling scheme is incorporated into a deferred shading pipeline to shade the image's perceptually relevant fragments while a pull-push algorithm interpolates the radiance for the rest of the image. Our approach does not impose any restrictions on the performed shading. We conduct a number of psycho-visual experiments to validate scene- and task-independence of our approach. The number of fragments that need to be shaded is reduced by 50 % to 80 %. Our algorithm scales favorably with increasing resolution and field-of-view, rendering it well-suited for head-mounted displays and wide-field-of-view projection.
Michael Stengel, Steve Grogorick, Martin Eisemann, Marcus A. Magnor
Comput. Graph. Forum3
2016 Orientation-Enhanced Parallel Coordinate Plots
abstract
Parallel Coordinate Plots (PCPs) is one of the most powerful techniques for the visualization of multivariate data. However, for large datasets, the representation suffers from clutter due to overplotting. In this case, discerning the underlying data information and selecting specific interesting patterns can become difficult. We propose a new and simple technique to improve the display of PCPs by emphasizing the underlying data structure. Our Orientation-enhanced Parallel Coordinate Plots (OPCPs) improve pattern and outlier discernibility by visually enhancing parts of each PCP polyline with respect to its slope. This enhancement also allows us to introduce a novel and efficient selection method, the Orientation-enhanced Brushing (O-Brushing). Our solution is particularly useful when multiple patterns are present or when the view on certain patterns is obstructed by noise. We present the results of our approach with several synthetic and real-world datasets. Finally, we conducted a user evaluation, which verifies the advantages of the OPCPs in terms of discernibility of information in complex data. It also confirms that O-Brushing eases the selection of data patterns in PCPs and reduces the amount of necessary user interactions compared to state-of-the-art brushing techniques.
Renata G. Raidou, Martin Eisemann, Marcel Breeuwer, Elmar Eisemann, Anna Vilanova
IEEE Trans. Vis. Comput. Graph.2
2015 Visibility sweeps for joint-hierarchical importance sampling of direct lighting for stochastic volume rendering
Thomas Kroes, Martin Eisemann, Elmar Eisemann
Graphics Interface2
2015 Interactive Scene Flow Editing for Improved Image-based Rendering and Virtual Spacetime Navigation
abstract
High-quality stereo and optical flow maps are essential for a multitude of tasks in visual media production, e.g. virtual camera navigation, disparity adaptation or scene editing. Rather than estimating stereo and optical flow separately, scene flow is a valid alternative since it combines both spatial and temporal information and recently surpassed the former two in terms of accuracy. However, since automated scene flow estimation is non-accurate in a number of situations, resulting rendering artifacts have to be corrected manually in each output frame, an elaborate and time-consuming task. We propose a novel workflow to edit the scene flow itself, catching the problem at its source and yielding a more flexible instrument for further processing. By integrating user edits in early stages of the optimization, we allow the use of approximate scribbles instead of accurate editing, thereby reducing interaction times. Our results show that editing the scene flow improves the quality of visual results considerably while requiring vastly less editing effort.
Kai Ruhl, Martin Eisemann, Anna Hilsmann, Peter Eisert, Marcus A. Magnor
ACM Multimedia2
2015 An Affordable Solution for Binocular Eye Tracking and Calibration in Head-mounted Displays
abstract
Immersion is the ultimate goal of head-mounted displays (HMD) for Virtual Reality (VR) in order to produce a convincing user experience. Two important aspects in this context are motion sickness, often due to imprecise calibration, and the integration of a reliable eye tracking. We propose an affordable hard- and software solution for drift-free eye-tracking and user-friendly lens calibration within an HMD. The use of dichroic mirrors leads to a lean design that provides the full field-of-view (FOV) while using commodity cameras for eye tracking. Our prototype supports personalizable lens positioning to accommodate for different interocular distances. On the software side, a model-based calibration procedure adjusts the eye tracking system and gaze estimation to varying lens positions. Challenges such as partial occlusions due to the lens holders and eye lids are handled by a novel robust monocular pupil-tracking approach. We present four applications of our work: Gaze map estimation, foveated rendering for depth of field, gaze-contingent level-of-detail, and gaze control of virtual avatars.
Michael Stengel, Steve Grogorick, Martin Eisemann, Elmar Eisemann, Marcus A. Magnor
ACM Multimedia3
2015 Non-obscuring binocular eye tracking for wide field-of-view head-mounted-displays
abstract
We present a complete hardware and software solution for integrating binocular eye tracking into current state-of-the-art lens-based Head-mounted Displays (HMDs) without affecting the user's wide field-of-view off the display. The system uses robust and efficient new algorithms for calibration and pupil tracking and allows realtime eye tracking and gaze estimation. Estimating the relative gaze direction of the user opens the door to a much wider spectrum of virtual reality applications and games when using HMDs. We show a 3d-printed prototype of a low-cost HMD with eye tracking that is simple to fabricate and discuss a variety of VR applications utilizing gaze estimation.
Michael Stengel, Steve Grogorick, Martin Eisemann, Elmar Eisemann, Marcus A. Magnor
VR3
2015 General and Robust Error Estimation and Reconstruction for Monte Carlo Rendering
abstract
Abstract Adaptive filtering techniques have proven successful in handling non‐uniform noise in Monte‐Carlo rendering approaches. A recent trend is to choose an optimal filter per pixel from a selection of non spatially‐varying filters. Nonetheless, the best filter choice is difficult to predict in the absence of a reference rendering. Our approach relies on the observation that the reconstruction error is locally smooth for a given filter. Hence, we propose to construct a dense error prediction from a small set of sparse but robust estimates. The filter selection is then formulated as a non‐local optimization problem, which we solve via graph cuts, to avoid visual artifacts due to inconsistent filter choices. Our approach does not impose any restrictions on the used filters, outperforms previous state‐of‐the‐art techniques and provides an extensible framework for future reconstruction techniques.
Pablo Bauszat, Martin Eisemann, Elmar Eisemann, Marcus A. Magnor
Comput. Graph. Forum2
2015 Sample-Based Manifold Filtering for Interactive Global Illumination and Depth of Field
abstract
Abstract We present a fast reconstruction filtering method for images generated with Monte Carlo–based rendering techniques. Our approach specializes in reducing global illumination noise in the presence of depth‐of‐field effects at very low sampling rates and interactive frame rates. We employ edge‐aware filtering in the sample space to locally improve outgoing radiance of each sample. The improved samples are then distributed in the image plane using a fast, linear manifold‐based approach supporting very large circles of confusion. We evaluate our filter by applying it to several images containing noise caused by Monte Carlo–simulated global illumination, area light sources and depth of field. We show that our filter can efficiently denoise such images at interactive frame rates on current GPUs and with as few as 4–16 samples per pixel. Our method operates only on the colour and geometric sample information output of the initial rendering process. It does not make any assumptions on the underlying rendering technique and sampling strategy and can therefore be implemented completely as a post‐process filter.
Pablo Bauszat, Martin Eisemann, S. John, Marcus A. Magnor
Comput. Graph. Forum2
2015 An Approach Toward Fast Gradient-Based Image Segmentation
abstract
In this paper, we present and investigate an approach to fast multilabel color image segmentation using convex optimization techniques. The presented model is in some ways related to the well-known Mumford-Shah model, but deviates in certain important aspects. The optimization problem has been designed with two goals in mind. The objective function should represent fundamental concepts of image segmentation, such as incorporation of weighted curve length and variation of intensity in the segmented regions, while allowing transformation into a convex concave saddle point problem that is computationally inexpensive to solve. This paper introduces such a model, the nontrivial transformation of this model into a convex-concave saddle point problem, and the numerical treatment of the problem. We evaluate our approach by applying our algorithm to various images and show that our results are competitive in terms of quality at unprecedentedly low computation times. Our algorithm allows high-quality segmentation of megapixel images in a few seconds and achieves interactive performance for low resolution images.
Benjamin Hell, Marc Kassubeck, Pablo Bauszat, Martin Eisemann, Marcus A. Magnor
IEEE Trans. Image Process.4
2015 Temporal Video Filtering and Exposure Control for Perceptual Motion Blur
abstract
We propose the computation of a perceptual motion blur in videos. Our technique takes the predicted eye motion into account when watching the video. Compared to traditional motion blur recorded by a video camera our approach results in a perceptual blur that is closer to reality. This postprocess can also be used to simulate different shutter effects or for other artistic purposes. It handles real and artificial video input, is easy to compute and has a low additional cost for rendered content. We illustrate its advantages in a user study using eye tracking.
Michael Stengel, Pablo Bauszat, Martin Eisemann, Elmar Eisemann, Marcus A. Magnor
IEEE Trans. Vis. Comput. Graph.3
2014 Garment Replacement in Monocular Video Sequences
abstract
We present a semi-automatic approach to exchange the clothes of an actor for arbitrary virtual garments in conventional monocular video footage as a postprocess. We reconstruct the actor's body shape and motion from the input video using a parameterized body model. The reconstructed dynamic 3D geometry of the actor serves as an animated mannequin for simulating the virtual garment. It also aids in scene illumination estimation, necessary to realistically light the virtual garment. An image-based warping technique ensures realistic compositing of the rendered virtual garment and the original video. We present results for eight real-world video sequences featuring complex test cases to evaluate performance for different types of motion, camera settings, and illumination conditions.
Lorenz Rogge, Felix Klose, Michael Stengel, Martin Eisemann, Marcus A. Magnor
ACM Trans. Graph.4
2013 Optimizing Apparent Display Resolution Enhancement for Arbitrary Videos
abstract
Display resolution is frequently exceeded by available image resolution. Recently, apparent display resolution enhancement (ADRE) techniques show how characteristics of the human visual system can be exploited to provide super-resolution on high refresh rate displays. In this paper, we address the problem of generalizing the ADRE technique to conventional videos of arbitrary content. We propose an optimization-based approach to continuously translate the video frames in such a way that the added motion enables apparent resolution enhancement for the salient image region. The optimization considers the optimal velocity, smoothness, and similarity to compute an appropriate trajectory. In addition, we provide an intuitive user interface that allows to guide the algorithm interactively and preserves important compositions within the video. We present a user study evaluating apparent rendering quality and show versatility of our method on a variety of general test scenes.
Michael Stengel, Martin Eisemann, Stephan Wenger, Benjamin Hell, Marcus A. Magnor
IEEE Trans. Image Process.2
2012 Geometry Presorting for Implicit Object Space Partitioning
abstract
Abstract We present a new data structure for object space partitioning that can be represented completely implicitly. The bounds of each node in the tree structure are recreated at run‐time from the scene objects contained therein. By applying a presorting procedure to the geometry, only a known fraction of the geometry is needed to locate the bounding planes of any node. We evaluate the impact of the implicit bounding plane representation and compare our algorithm to a classic bounding volume hierarchy. Though the representation is completely implicit, we still achieve interactive frame rates on commodity hardware.
Martin Eisemann, Pablo Bauszat, Stefan Guthe, Marcus A. Magnor
Comput. Graph. Forum1
2012 Selecting Coherent and Relevant Plots in Large Scatterplot Matrices
abstract
Abstract The scatterplot matrix (SPLOM) is a well‐established technique to visually explore high‐dimensional data sets. It is characterized by the number of scatterplots (plots) of which it consists of. Unfortunately, this number quadratically grows with the number of the data set’s dimensions. Thus, an SPLOM scales very poorly. Consequently, the usefulness of SPLOMs is restricted to a small number of dimensions. For this, several approaches already exist to explore such ‘small’ SPLOMs. Those approaches address the scalability problem just indirectly and without solving it. Therefore, we introduce a new greedy approach to manage ‘large’ SPLOMs with more than 100 dimensions. We establish a combined visualization and interaction scheme that produces intuitively interpretable SPLOMs by combining known quality measures, a pre‐process reordering and a perception‐based abstraction. With this scheme, the user can interactively find large amounts of relevant plots in large SPLOMs.
Dirk J. Lehmann, Georgia Albuquerque, Martin Eisemann, Marcus A. Magnor, Holger Theisel
Comput. Graph. Forum3
2011 Edge-constrained image compositing
Martin Eisemann, Daniel Gohlke, Marcus A. Magnor
Graphics Interface1
2011 Guided Image Filtering for Interactive High-quality Global Illumination
abstract
Abstract Interactive computation of global illumination is a major challenge in current computer graphics research. Global illumination heavily affects the visual quality of generated images. It is therefore a key attribute for the perception of photo‐realistic images. Path tracing is able to simulate the physical behaviour of light using Monte Carlo techniques. However, the computational burden of this technique prohibits interactive rendering times on standard commodity hardware in high‐quality. Trying to solve the Monte Carlo integration with fewer samples results in characteristic noisy images. Global illumination filtering methods take advantage of the fact that the integral for neighbouring pixels may be very similar. Averaging samples of similar characteristics in screen‐space may approximate the correct integral, but may result in visible outliers. In this paper, we present a novel path tracing pipeline based on an edge‐aware filtering method for the indirect illumination which produces visually more pleasing results without noticeable outliers. The key idea is not to filter the noisy path traced images but to use it as a guidance to filter a second image composed from characteristic scene attributes that do not contain noise by default. We show that our approach better approximates the Monte Carlo integral compared to previous methods. Since the computation is carried out completely in screen‐space it is therefore applicable to fully dynamic scenes, arbitrary lighting and allows for high‐quality path tracing at interactive frame rates on commodity hardware.
Pablo Bauszat, Martin Eisemann, Marcus A. Magnor
Comput. Graph. Forum2
2011 Motion Field Estimation from Alternate Exposure Images
abstract
Traditional optical flow algorithms rely on consecutive short-exposed images. In this work, we make use of an additional long-exposed image for motion field estimation. Long-exposed images integrate motion information directly in the form of motion-blur. With this additional information, more robust and accurate motion fields can be estimated. In addition, the moment of occlusion can be determined. Considering the basic signal-theoretical problem in motion field estimation, we exploit the fact that long-exposed images integrate motion information to prevent temporal aliasing. A suitable image formation model relates the long-exposed image to preceding and succeeding short-exposed images in terms of dense 2D motion and per-pixel occlusion/disocclusion timings. Based on our image formation model, we describe a practical variational algorithm to estimate the motion field not only for visible image regions but also for regions getting occluded. Results for synthetic as well as real-world scenes demonstrate the validity of the approach.
Anita Sellent, Martin Eisemann, Bastian Goldlücke, Daniel Cremers, Marcus A. Magnor
IEEE Trans. Pattern Anal. Mach. Intell.2
2011 Automated Analytical Methods to Support Visual Exploration of High-Dimensional Data
abstract
Visual exploration of multivariate data typically requires projection onto lower dimensional representations. The number of possible representations grows rapidly with the number of dimensions, and manual exploration quickly becomes ineffective or even unfeasible. This paper proposes automatic analysis methods to extract potentially relevant visual structures from a set of candidate visualizations. Based on features, the visualizations are ranked in accordance with a specified user task. The user is provided with a manageable number of potentially useful candidate visualizations, which can be used as a starting point for interactive data analysis. This can effectively ease the task of finding truly useful visualizations and potentially speed up the data exploration task. In this paper, we present ranking measures for class-based as well as non-class-based scatterplots and parallel coordinates visualizations. The proposed analysis methods are evaluated on different data sets.
Andrada Tatu, Georgia Albuquerque, Martin Eisemann, Peter Bak, Holger Theisel, Marcus A. Magnor, Daniel A. Keim
IEEE Trans. Vis. Comput. Graph.3
2010 Photo zoom: high resolution from unordered image collections
Martin Eisemann, Elmar Eisemann, Hans-Peter Seidel, Marcus A. Magnor
Graphics Interface1
2008 Floating Textures
abstract
Abstract We present a novel multi‐view, projective texture mapping technique. While previous multi‐view texturing approaches lead to blurring and ghosting artefacts if 3D geometry and/or camera calibration are imprecise, we propose a texturing algorithm that warps (“floats”) projected textures during run‐time to preserve crisp, detailed texture appearance. Our GPU implementation achieves interactive to real‐time frame rates. The method is very generally applicable and can be used in combination with many image‐based rendering methods or projective texturing applications. By using Floating Textures in conjunction with, e.g., visual hull rendering, light field rendering, or free‐viewpoint video, improved rendering results are obtained from fewer input images, less accurately calibrated cameras, and coarser 3D geometry proxies.
Martin Eisemann, Bert de Decker, Marcus A. Magnor, Philippe Bekaert, Edilson de Aguiar, Naveed Ahmed 0001, Christian Theobalt, Anita Sellent
Comput. Graph. Forum1