Thomas Gottwald

Chamuditha Jayanga Galappaththige, Thomas Gottwald, Peter Stehr et al.

Recent advances in 3D Gaussian Splatting have enabled impressive photorealistic novel view synthesis. However, to transition from a pure rendering engine to a reliable spatial map for autonomous agents and safety-critical applications, knowing where the representation is uncertain is as important as the rendering fidelity itself. We bridge this critical gap by introducing a lightweight, plug-and-play framework for pixel-wise, view-dependent predictive uncertainty estimation. Our post-hoc method formulates uncertainty as a Bayesian-regularized linear least-squares optimization over reconstruction residuals. This architecture-agnostic approach extracts a per-primitive uncertainty channel without modifying the underlying scene representation or degrading baseline visual fidelity. Crucially, we demonstrate that providing this actionable reliability signal successfully translates 3D Gaussian splatting into a trustworthy spatial map, further improving state-of-the-art performance across three critical downstream perception tasks: active view selection, pose-agnostic scene change detection, and pose-agnostic anomaly detection.

Edgar Heinert, Thomas Gottwald, Annika Mütze et al.

Previous works studied how deep neural networks (DNNs) perceive image content in terms of their biases towards different image cues, such as texture and shape. Previous methods to measure shape and texture biases are typically style-transfer-based and limited to DNNs for image classification. In this work, we provide a new evaluation procedure consisting of 1) a cue-decomposition method that comprises two AI-free data pre-processing methods extracting shape and texture cues, respectively, and 2) a novel cue-decomposition shape bias evaluation metric that leverages the cue-decomposition data. For application purposes we introduce a corresponding cue-decomposition robustness metric that allows for the estimation of the robustness of a DNN w.r.t. image corruptions. In our numerical experiments, our findings for biases in image classification DNNs align with those of previous evaluation metrics. However, our cue-decomposition robustness metric shows superior results in terms of estimating the robustness of DNNs. Furthermore, our results for DNNs on the semantic segmentation datasets Cityscapes and ADE20k for the first time shed light into the biases of semantic segmentation DNNs.

Thomas Gottwald, Edgar Heinert, Matthias Rottmann

In this work, we present a novel method for uncertainty estimation (UE) in Gaussian Splatting. UE is crucial for using Gaussian Splatting in critical applications such as robotics and medicine. Previous methods typically estimate the variance of Gaussian primitives and use the rendering process to obtain pixel-wise uncertainties. Our method establishes primitive representations of error and visibility of trainings views, which carries meaningful uncertainty information. This representation is obtained by projection of training error and visibility onto the primitives. Uncertainties of novel views are obtained by rendering the primitive representations of uncertainty for those novel views, yielding uncertainty feature maps. To aggregate these uncertainty feature maps of novel views, we perform a pixel-wise regression on holdout data. In our experiments, we analyze the different components of our method, investigating various combinations of uncertainty feature maps and regression models. Furthermore, we considered the effect of separating splatting into foreground and background. Our UEs show high correlations to true errors, outperforming state-of-the-art methods, especially on foreground objects. The trained regression models show generalization capabilities to new scenes, allowing uncertainty estimation without the need for holdout data.