Subspace clustering has attracted much attention because of its ability to group unlabeled high-dimensional data into multiple subspaces. Existing graph-based subspace clustering methods focus on either the sparsity of data affinity or the low rank of data affinity. Thus, the quality of data affinity plays an essential role in the performance of subspace clustering. However, the real-world data are generally high-dimensional, complex, and heterogeneous multi-source data, so that the data affinity learned by these methods cannot be completely dependent. Moreover, since these approaches always ignore the intrinsic structure of data, their grouping effect is relatively low. In this paper, we propose a novel unsupervised algorithm, called Structure-Aware Subspace Clustering (SASC), to address the above issues. SASC considers local and global correlation structures simultaneously to capture the intrinsic structure. Further, it integrates the captured structure into representation learning to gain a relatively precise data affinity. It is powerful to promote an all-around grouping effect and enhances the robustness and applicability of subspace clustering. Experiments on various benchmark datasets, including bioinformatics, handwritten digit, object image, and speech signal, demonstrate the effectiveness of the proposed algorithm.

Nonnegative Matrix Factorization (NMF) is a popular technique for machine learning. Its power is that it can decompose a nonnegative matrix into two nonnegative factors whose product well approximates the nonnegative matrix. However, the nonnegative constraint of the data matrix limits its application. Additionally, the representations learned by NMF fail to respect the intrinsic geometric structure of the data. In this paper, we propose a novel unsupervised matrix factorization method, called Robust Structured Convex Nonnegative Matrix Factorization (RSCNMF). RSCNMF not only achieves meaningful factorizations of the mixed-sign data, but also learns a discriminative representation by leveraging local and global structures of the data. Moreover, it introduces the L _2,1 -norm loss function to deal with noise and outliers, and exploits the L _2,1 -norm feature regularizer to select discriminative features across all the samples. We develop an alternate iterative scheme to solve such a new model. The convergence of RSCNMF is proven theoretically and verified empirically. The experimental results on eight real-world data sets show that our RSCNMF algorithm matches or outperforms the state-of-the-art methods.

Consumer-level omnidirectional video offers an economically viable means to create virtual reality (VR) assets, enabling users to explore and interact within a fully immersive visual environment. However, editing such videos, particularly those with 360${}^{\circ }$ views and dynamic objects, poses significant challenges. Existing approaches to representing and manipulating omnidirectional content—whether designed for typical 2D perspective imagery or panoramas—often fail to adequately capture the complex spatiotemporal relationships crucial for producing high-quality, editable outputs in dynamic, panoramic settings. To overcome these challenges, we introduce OmniPlane, a novel method that leverages spherical spatiotemporal feature grids to empower the representation and editability of real-world dynamic omnidirectional environments casually captured by commodity omnidirectional cameras. OmniPlane computes spatiotemporal features by fusing vectors or matrices from each learnable spatial and spatiotemporal feature plane within a spherical coordinate system, complemented by a specifically designed weighted sampling strategy respecting the inherent spherical distribution of omnidirectional content. These learned feature planes can be flexibly decomposed into palette-based color bases. This innovative method not only enhances the representation capability of omnidirectional content and dynamics but also enables the recoloring of omnidirectional videos. Extensive experiments and a dedicated user study validate the superior performance of our proposed method in facilitating recolorable representations of dynamic omnidirectional environments.

Due to recent advances in 3D reconstruction from RGB images, it is now possible to create photorealistic representations of real-world scenes that only require minutes to be reconstructed and can be rendered in real time. In particular, 3D Gaussian splatting shows promising results, outperforming preceding reconstruction methods while simultaneously reducing the overall computational requirements. The main success of 3D Gaussian splatting relies on the efficient use of a differentiable rasterizer to render the Gaussian scene representation. One major drawback of this method is its underlying pinhole camera model. In this paper, we propose an extension of the existing method that removes this constraint and enables scene reconstructions using arbitrary camera optics such as highly distorting fisheye lenses. Our method achieves this by applying a differentiable warping function to the Gaussian scene representation. Additionally, we reduce overfitting in outdoor scenes by utilizing a learnable skybox, reducing the presence of floating artifacts within the reconstructed scene. Based on synthetic and real-world image datasets, we show that our method is capable of creating an accurate scene reconstruction from highly distorted images and rendering photorealistic images from such reconstructions.

Monitoring robotic manipulators is essential in highly automated environments, where optical cameras can provide precise and dense information while suffering from line-of-sight occlusions. This paper introduces a lightweight, learning-based solution to address these occlusions in robot-camera systems. We employ a small MLP (Multilayer Perceptron) to learn occluded spaces and use its gradients for active occlusion avoidance. To generate training data, we use smooth random robot trajectories that uniformly sample the robot’s configuration space. Additionally, we reduce data acquisition time by modifying the state-of-the-art 3D Gaussian Splatting (3DGS) method to create a near-photorealistic model of the manipulator for generating extensive training datasets. Our experiments show that the proposed approach achieves a balanced accuracy of 94.7 %, which improves upon a previous method by 20 % while reducing the sampling time from 4.5 h to 5 min. We demonstrate the application of the proposed method in two real-world test cases and achieve continuous visibility. Through the use of rigid 3DGS, we significantly improved upon previous results. By reducing the data sampling duration from hours to minutes, the practicality and applicability of our approach in real-world scenarios have been substantially enhanced.

We propose a method to reconstruct dynamic fire in 3D from a limited set of camera views with a Gaussian-based spatiotemporal representation. Capturing and reconstructing fire and its dynamics is highly challenging due to its volatile nature, transparent quality, and multitude of high-frequency features. Despite these challenges, we aim to reconstruct fire from only three views, which consequently requires solving for under-constrained geometry. We solve this by separating the static background from the dynamic fire region by combining dense multi-view stereo images with monocular depth priors. The fire is initialized as a 3D flow field, obtained by fusing per-view dense optical flow projections. To capture the high frequency features of fire, each 3D Gaussian encodes a lifetime and linear velocity to match the dense optical flow. To ensure sub-frame temporal alignment across cameras we employ a custom hardware synchronization pattern -- allowing us to reconstruct fire with affordable commodity hardware. Our quantitative and qualitative validations across numerous reconstruction experiments demonstrate robust performance for diverse and challenging real fire scenarios.