VLDB 2026 Research / reviewers in the wild / expert
Stefanie Walz
dblp:260/6687
· DBLP profile ↗
9ranked-venue papers
2as first author
9since 2021 · last 2026
0009-0002-4819-3350ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 8 · 2 first-author · 8 since 2021Graphics, computer vision, multimedia, augmented reality and games · 6 · 1 first-author · 6 since 2021Systems, architecture and hardware · 1 · 1 first-author · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Too Tiny to See: Hazardous Obstacle Detection Dataset and EvaluationabstractWe introduce a novel dataset and evaluation approach for long-range depth prediction of small objects that enables consistent comparison across direct time-of-flight (ToF) sensors and learned depth estimation methods. In autonomous driving, accurate depth perception is essential for identifying and locating surrounding elements and determining safe driving paths. Traditional depth metrics focus on distance accuracy but fail to evaluate a key factor at long ranges: distinguishing small, slightly elevated structures from the ground - crucial for anticipating obstacles and making safe driving decisions. At far distances, imagebased systems suffer from resolution limitations that tend to oversmooth the ground plane, causing elevated objects to be mistaken as texture patterns on the surface. Conversely, scanning LiDAR systems may return only a single point from an elevated object due to steep incident angles and sparse returns, preventing accurate differentiation from the ground. This hampers a fair comparison of object presence and shape. To address this, we propose a framework that evaluates how well the estimated point clouds preserve semantic content relative to ground-truth data. We leverage neural network-based feature extraction to assess structural similarity, enabling a modality-agnostic evaluation of object-level fidelity. Our method also supports analysis of the trade-off between resolution and accuracy, investigating performances across sensor types - such as highresolution cameras versus LiDAR - and conditions, including day and night scenarios. This enables a more comprehensive understanding of the capabilities and limitations of current depth prediction approaches in real-world settings. Topi Miekkala, Samuel Brucker, Stefanie Walz, Filippo Ghilotti, Andrea Ramazzina, Dominik Scheuble, Pasy Pyykonen, Mario Bijelic, Felix Heide |
3DV | 3 |
| 2025 | A Multi-Modal Benchmark for Long-Range Depth Evaluation in Adverse Weather ConditionsabstractDepth estimation is a cornerstone computer vision application that is critical for scene understanding and autonomous driving. In real-world scenarios, achieving reliable depth perception under adverse weather—e.g. in fog and rain—is crucial to ensure safety and system robustness. However, quantitatively evaluating the performances of depth estimation methods in these scenarios is challenging due to the difficulty of obtaining ground truth data. A promising approach is using weather chambers to simulate diverse weather conditions in a controlled environment. However, current datasets are limited in distance and lack a dense ground truth. To address this gap, we introduce a novel evaluation benchmark that extends depth evaluation up to 200 meters under clear, foggy, and rainy conditions. To this end, we employ a multimodal sensor setup, including state-of-the-art stereo RGB, RCCB, Gated camera systems, and a long-range LiDAR sensor. Moreover, we record a digital twin of the test facility sampled at a millimeter scale using a high-end geodesic laser scanner. This comprehensive benchmark allows for the evaluation of different models and multiple sensing modalities in a more precise and accurate manner, as well as at far distances. Data and code will be released upon publication. Stefanie Walz, Andrea Ramazzina, Dominik Scheuble, Samuel Brucker, Alexander Zuber, Werner Ritter, Mario Bijelic, Felix Heide |
IROS | 1 |
| 2024 | Cross-spectral Gated-RGB Stereo Depth EstimationabstractGated cameras flood-illuminate a scene and capture the time-gated impulse response of a scene. By employing nanosecond-scale gates, existing sensors are capable of capturing mega-pixel gated images, delivering dense depth improving on today's LiDAR sensors in spatial resolution and depth precision. Although gated depth estimation methods deliver a million of depth estimates per frame, their res-olution is still an order below existing RGB imaging methods. In this work, we combine high-resolution stereo HDR RCCB cameras with gated imaging, allowing us to exploit depth cues from active gating, multi-view RGB and multi-view NIR sensing - multi-view and gated cues across the entire spectrum. The resulting capture system consists only of low-cost CMOS sensors and flood-illumination. We pro-pose a novel stereo-depth estimation method that is capa-ble of exploiting these multi-modal multi-view depth cues, including the active illumination that is measured by the RCCB camera when removing the IR-cut filter. The pro-posed method achieves accurate depth at long ranges, out-performing the next best existing method by 39% for ranges of 100 to 220 m in MAE on accumulated LiDAR ground-truth. Our code, models and datasets are available here11https://light.princeton.edu/gatedrccbstereo/. Samuel Brucker, Stefanie Walz, Mario Bijelic, Felix Heide |
CVPR | 2 |
| 2024 | Gated Fields: Learning Scene Reconstruction from Gated VideosabstractReconstructing outdoor 3D scenes from temporal observations is a challenge that recent work on neural fields has offered a new avenue for. However, existing methods that recover scene properties, such as geometry, appearance, or radiance, solely from RGB captures often fail when handling poorly-lit or texture-deficient regions. Similarly, recovering scenes with scanning LiDAR sensors is also difficult due to their low angular sampling rate which makes recovering expansive real-world scenes difficult. Tackling these gaps, we introduce Gated Fields - a neural scene reconstruction method that utilizes active gated video sequences. To this end, we propose a neural rendering approach that seamlessly incorporates time-gated capture and illumination. Our method exploits the intrinsic depth cues in the gated videos, achieving precise and dense geometry reconstruction irrespective of ambient illumination conditions. We validate the method across day and night scenarios and find that Gated Fields compares favorably to RGB and LiDAR reconstruction methods. Our code and datasets are available here11https://light.princeton.edu/gatedfields/. Andrea Ramazzina, Stefanie Walz, Pragyan Dahal, Mario Bijelic, Felix Heide |
CVPR | 2 |
| 2024 | Real-time Environment Condition Classification for Autonomous VehiclesabstractCurrent autonomous driving technologies are being rolled out in geo-fenced areas with well-defined operation conditions such as time of operation, area, weather conditions and road conditions. In this way, challenging conditions as adverse weather, slippery road or densely-populated city centers can be excluded. In order to lift the geo-fenced restriction and allow a more dynamic availability of autonomous driving functions, it is necessary for the vehicle to autonomously perform an environment condition assessment in real time to identify when the system cannot operate safely and either stop operation or require the resting passenger to take control. In particular, adverse-weather challenges are a fundamental limitation as sensor performance degenerates quickly, prohibiting the use of sensors such as cameras to locate and monitor road signs, pedestrians or other vehicles. To address this issue, we train a deep learning model to identify outdoor weather and dangerous road conditions, enabling a quick reaction to new situations and environments. We achieve this by introducing an improved taxonomy and label hierarchy for a state-of-the-art adverse-weather dataset, relabelling it with a novel semi-automated labeling pipeline. Using the novel proposed dataset and hierarchy, we train RECNet, a deep learning model for the classification of environment conditions from a single RGB frame. We outperform baseline models by relative 16% in F1-Score, while maintaining a real-time capable performance of 20 Hz. The code is published here1. Marco Introvigne, Andrea Ramazzina, Stefanie Walz, Dominik Scheuble, Mario Bijelic |
IV | 3 |
| 2024 | HINT: Learning Complete Human Neural Representations from Limited ViewpointsabstractNo augmented application is possible without animated humanoid avatars. At the same time, generating human replicas from real-world monocular hand-held or robotic sensor setups is challenging due to the limited availability of views. Previous work showed the feasibility of virtual avatars but required the presence of 360° views of the targeted subject. To address this issue, we propose HINT, a NeRF-based algorithm able to learn a detailed and complete human model from limited viewing angles. We achieve this by introducing a symmetry prior, regularization constraints, and training cues from large human datasets. In particular, we introduce a sagittal plane symmetry prior to the appearance of the human, directly supervise the density function of the human model using explicit 3D body modeling, and leverage a co-learned human digitization network as additional supervision for the unseen angles.As a result, our method can reconstruct complete humans even from a few viewing angles, increasing performance by more than 15% PSNR compared to previous state-of-the-art algorithms. Alessandro Sanvito, Andrea Ramazzina, Stefanie Walz, Mario Bijelic, Felix Heide |
IV | 3 |
| 2023 | Gated Stereo: Joint Depth Estimation from Gated and Wide-Baseline Active Stereo CuesabstractWe propose Gated Stereo, a high-resolution and long-range depth estimation technique that operates on active gated stereo images. Using active and high dynamic range passive captures, Gated Stereo exploits multi-view cues alongside time-of-flight intensity cues from active gating. To this end, we propose a depth estimation method with a monocular and stereo depth prediction branch which are combined in a final fusion stage. Each block is supervised through a combination of supervised and gated self-supervision losses. To facilitate training and validation, we acquire a long-range synchronized gated stereo dataset for automotive scenarios. We find that the method achieves an improvement of more than 50 % MAE compared to the next best RGB stereo method, and 74 % MAE to existing monocular gated methods for distances up to 160 m. Our code, models and datasets are available here11https://light.princeton.edu/gatedstereo/. Stefanie Walz, Mario Bijelic, Andrea Ramazzina, Amanpreet Walia, Fahim Mannan, Felix Heide |
CVPR | 1 |
| 2023 | ScatterNeRF: Seeing Through Fog with Physically-Based Inverse Neural RenderingabstractVision in adverse weather conditions, whether it be snow, rain, or fog is challenging. In these scenarios, scattering and attenuation severly degrades image quality. Handling such inclement weather conditions, however, is essential to operate autonomous vehicles, drones and robotic applications where human performance is impeded the most. A large body of work explores removing weather-induced image degradations with dehazing methods. Most methods rely on single images as input and struggle to generalize from synthetic fully-supervised training approaches or to generate high fidelity results from unpaired real-world datasets. With data as bottleneck and most of today’s training data relying on good weather conditions with inclement weather as outlier, we rely on an inverse rendering approach to reconstruct the scene content. We introduce ScatterNeRF, a neural rendering method which adequately renders foggy scenes and decomposes the fog-free background from the participating media – exploiting the multiple views from a short automotive sequence without the need for a large training data corpus. Instead, the rendering approach is optimized on the multi-view scene itself, which can be typically captured by an autonomous vehicle, robot or drone during operation. Specifically, we propose a disentangled representation for the scattering volume and the scene objects, and learn the scene reconstruction with physics-inspired losses. We validate our method by capturing multi-view In-the-Wild data and controlled captures in a large-scale fog chamber. Our code and datasets are available at https://light.princeton.edu/scatternerf. Andrea Ramazzina, Mario Bijelic, Stefanie Walz, Alessandro Sanvito, Dominik Scheuble, Felix Heide |
ICCV | 3 |
| 2022 | Gated2Gated: Self-Supervised Depth Estimation from Gated ImagesabstractGated cameras hold promise as an alternative to scanning LiDAR sensors with high-resolution 3D depth that is robust to back-scatter in fog, snow, and rain. Instead of sequentially scanning a scene and directly recording depth via the photon time-of-flight, as in pulsed LiDAR sensors, gated imagers encode depth in the relative intensity of a handful of gated slices, captured at megapixel resolution. Although existing methods have shown that it is possible to decode high-resolution depth from such measurements, these methods require synchronized and calibrated LiDAR to supervise the gated depth decoder - prohibiting fast adoption across geographies, training on large unpaired datasets, and exploring alternative applications outside of automotive use cases. In this work, propose an entirely self-supervised depth estimation method that uses gated in-tensity profiles and temporal consistency as a training signal. The proposed model is trained end-to-end from gated video sequences, does not require LiDAR or RGB data, and learns to estimate absolute depth values. We take gated slices as input and disentangle the estimation of the scene albedo, depth, and ambient light, which are then used to learn to reconstruct the input slices through a cyclic loss. We rely on temporal consistency between a given frame and neighboring gated slices to estimate depth in regions with shadows and reflections. We experimentally validate that the proposed approach outperforms existing super-vised and self-supervised depth estimation methods based on monocular RGB and stereo images, as well as super-vised methods based on gated images. Code is available at https://github.com/princeton-computational-imaging/Gated2Gated. Amanpreet Walia, Stefanie Walz, Mario Bijelic, Fahim Mannan, Frank D. Julca-Aguilar, Michael S. Langer, Werner Ritter, Felix Heide |
CVPR | 2 |