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EgoWorld: Translating Exocentric View to Egocentric View using Rich Exocentric Observations

Park, Junho, Ye, Andrew Sangwoo, Kwon, Taein

arXiv.org Artificial Intelligence

Egocentric vision is essential for both human and machine visual understanding, particularly in capturing the detailed hand-object interactions needed for manipulation tasks. Translating third-person views into first-person views significantly benefits augmented reality (AR), virtual reality (VR) and robotics applications. However, current exocentric-to-egocentric translation methods are limited by their dependence on 2D cues, synchronized multi-view settings, and unrealistic assumptions such as necessity of initial egocentric frame and relative camera poses during inference. To overcome these challenges, we introduce EgoWorld, a novel two-stage framework that reconstructs an egocentric view from rich exocentric observations, including projected point clouds, 3D hand poses, and textual descriptions. Our approach reconstructs a point cloud from estimated exocentric depth maps, reprojects it into the egocentric perspective, and then applies diffusion-based inpainting to produce dense, semantically coherent egocentric images. Evaluated on the H2O and TACO datasets, EgoWorld achieves state-of-the-art performance and demonstrates robust generalization to new objects, actions, scenes, and subjects. Moreover, EgoWorld shows promising results even on unlabeled real-world examples.


ObjectRelator: Enabling Cross-View Object Relation Understanding in Ego-Centric and Exo-Centric Videos

Fu, Yuqian, Wang, Runze, Fu, Yanwei, Paudel, Danda Pani, Huang, Xuanjing, Van Gool, Luc

arXiv.org Artificial Intelligence

In this paper, we focus on the Ego-Exo Object Correspondence task, an emerging challenge in the field of computer vision that aims to map objects across ego-centric and exo-centric views. We introduce ObjectRelator, a novel method designed to tackle this task, featuring two new modules: Multimodal Condition Fusion (MCFuse) and SSL-based Cross-View Object Alignment (XObjAlign). MCFuse effectively fuses language and visual conditions to enhance target object localization, while XObjAlign enforces consistency in object representations across views through a self-supervised alignment strategy. Extensive experiments demonstrate the effectiveness of ObjectRelator, achieving state-of-the-art performance on Ego2Exo and Exo2Ego tasks with minimal additional parameters. This work provides a foundation for future research in comprehensive cross-view object relation understanding highlighting the potential of leveraging multimodal guidance and cross-view alignment. Codes and models will be released to advance further research in this direction.


The next Tron game is an isometric action adventure due out in 2025

Engadget

The next Tron game is a follow-up to Tron: Identity, but it's also something completely new. Where Tron: Identity was a visual novel, Tron: Catalyst is an isometric action game with a looping narrative, and it's coming to PC, PlayStation 5, Xbox Series X/S and Switch in 2025. Tron: Catalyst is in development at Bithell Games, the award-winning studio behind Tron: Identity, John Wick Hex and Thomas Was Alone. In Tron: Catalyst, players return to the Arq Grid, a virtual world that's evolved without human input, creating a siloed, Galapagos Islands type of space populated by sentient computer programs. The protagonist is Exo, a program who's able to relive segments of time by exploiting a system-level glitch that no one else can sense.


Exploration by Optimization with Hybrid Regularizers: Logarithmic Regret with Adversarial Robustness in Partial Monitoring

Tsuchiya, Taira, Ito, Shinji, Honda, Junya

arXiv.org Machine Learning

Partial monitoring is a generic framework of online decision-making problems with limited observations. To make decisions from such limited observations, it is necessary to find an appropriate distribution for exploration. Recently, a powerful approach for this purpose, exploration by optimization (ExO), was proposed, which achieves the optimal bounds in adversarial environments with follow-the-regularized-leader for a wide range of online decision-making problems. However, a naive application of ExO in stochastic environments significantly degrades regret bounds. To resolve this problem in locally observable games, we first establish a novel framework and analysis for ExO with a hybrid regularizer. This development allows us to significantly improve the existing regret bounds of best-of-both-worlds (BOBW) algorithms, which achieves nearly optimal bounds both in stochastic and adversarial environments. In particular, we derive a stochastic regret bound of $O(\sum_{a \neq a^*} k^2 m^2 \log T / \Delta_a)$, where $k$, $m$, and $T$ are the numbers of actions, observations and rounds, $a^*$ is an optimal action, and $\Delta_a$ is the suboptimality gap for action $a$. This bound is roughly $\Theta(k^2 \log T)$ times smaller than existing BOBW bounds. In addition, for globally observable games, we provide a new BOBW algorithm with the first $O(\log T)$ stochastic bound.


Towards Efficient and Exact Optimization of Language Model Alignment

Ji, Haozhe, Lu, Cheng, Niu, Yilin, Ke, Pei, Wang, Hongning, Zhu, Jun, Tang, Jie, Huang, Minlie

arXiv.org Artificial Intelligence

The alignment of language models with human preferences is vital for their application in real-world tasks. The problem is formulated as optimizing the model's policy to maximize the expected reward that reflects human preferences with minimal deviation from the initial policy. While considered as a straightforward solution, reinforcement learning (RL) suffers from high variance in policy updates, which impedes efficient policy improvement. Recently, direct preference optimization (DPO) was proposed to directly optimize the policy from preference data. Though simple to implement, DPO is derived based on the optimal policy that is not assured to be achieved in practice, which undermines its convergence to the intended solution. In this paper, we propose efficient exact optimization (EXO) of the alignment objective. We prove that EXO is guaranteed to optimize in the same direction as the RL algorithms asymptotically for arbitary parametrization of the policy, while enables efficient optimization by circumventing the complexities associated with RL algorithms. We compare our method to DPO with both theoretical and empirical analyses, and further demonstrate the advantages of our method over existing approaches on realistic human preference data.


Reducing Causality to Functions with Structural Models

Miao, Tianyi

arXiv.org Artificial Intelligence

The precise definition of causality is currently an open problem in philosophy and statistics. We believe causality should be defined as functions (in mathematics) that map causes to effects. We propose a reductive definition of causality based on Structural Functional Model (SFM). Using delta compression and contrastive forward inference, SFM can produce causal utterances like "X causes Y" and "X is the cause of Y" that match our intuitions. We compile a dataset of causal scenarios and use SFM in all of them. SFM is compatible with but not reducible to probability theory. We also compare SFM with other theories of causation and apply SFM to downstream problems like free will, causal explanation, and mental causation.


Exploiting Action Impact Regularity and Exogenous State Variables for Offline Reinforcement Learning

Liu, Vincent (University of Alberta) | Wright, James R. (University of Alberta) | White, Martha (University of Alberta)

Journal of Artificial Intelligence Research

Offline reinforcement learning--learning a policy from a batch of data--is known to be hard for general MDPs. These results motivate the need to look at specific classes of MDPs where offline reinforcement learning might be feasible. In this work, we explore a restricted class of MDPs to obtain guarantees for offline reinforcement learning. The key property, which we call Action Impact Regularity (AIR), is that actions primarily impact a part of the state (an endogenous component) and have limited impact on the remaining part of the state (an exogenous component). AIR is a strong assumption, but it nonetheless holds in a number of real-world domains including financial markets. We discuss algorithms that exploit the AIR property, and provide a theoretical analysis for an algorithm based on Fitted-Q Iteration. Finally, we demonstrate that the algorithm outperforms existing offline reinforcement learning algorithms across different data collection policies in simulated and real world environments where the regularity holds.


Exploiting Action Impact Regularity and Exogenous State Variables for Offline Reinforcement Learning

Liu, Vincent, Wright, James R., White, Martha

arXiv.org Artificial Intelligence

Offline reinforcement learning -- learning a policy from a batch of data -- is known to be hard for general MDPs. These results motivate the need to look at specific classes of MDPs where offline reinforcement learning might be feasible. In this work, we explore a restricted class of MDPs to obtain guarantees for offline reinforcement learning. The key property, which we call Action Impact Regularity (AIR), is that actions primarily impact a part of the state (an endogenous component) and have limited impact on the remaining part of the state (an exogenous component). AIR is a strong assumption, but it nonetheless holds in a number of real-world domains including financial markets. We discuss algorithms that exploit the AIR property, and provide a theoretical analysis for an algorithm based on Fitted-Q Iteration. Finally, we demonstrate that the algorithm outperforms existing offline reinforcement learning algorithms across different data collection policies in simulated and real world environments where the regularity holds.


Reinforcement Learning with Exogenous States and Rewards

Trimponias, George, Dietterich, Thomas G.

arXiv.org Artificial Intelligence

Exogenous state variables and rewards can slow reinforcement learning by injecting uncontrolled variation into the reward signal. This paper formalizes exogenous state variables and rewards and shows that if the reward function decomposes additively into endogenous and exogenous components, the MDP can be decomposed into an exogenous Markov Reward Process (based on the exogenous reward) and an endogenous Markov Decision Process (optimizing the endogenous reward). Any optimal policy for the endogenous MDP is also an optimal policy for the original MDP, but because the endogenous reward typically has reduced variance, the endogenous MDP is easier to solve. We study settings where the decomposition of the state space into exogenous and endogenous state spaces is not given but must be discovered. The paper introduces and proves correctness of algorithms for discovering the exogenous and endogenous subspaces of the state space when they are mixed through linear combination. These algorithms can be applied during reinforcement learning to discover the exogenous space, remove the exogenous reward, and focus reinforcement learning on the endogenous MDP. Experiments on a variety of challenging synthetic MDPs show that these methods, applied online, discover large exogenous state spaces and produce substantial speedups in reinforcement learning.


Exo acquires Medo AI to improve ultrasound imaging

#artificialintelligence

Redwood City, California-based Exo intends to integrate Medo's proprietary Sweep AI technology into its ultrasound platform to make the imaging modality more accessible to a wider range of caregivers. No financial terms for the acquisition were disclosed. According to a news release, Canada-based Medo's ultrasound AI technology radically lowers the expertise required to diagnose common and critical conditions through automated image acquisition and interpretation, giving non-experts the ability to conduct high-quality exams quickly and accurately. The company brings with it two FDA-cleared AI algorithms, as well as more in development, plus access to an extensive library of millions of ultrasound images and longitudinal health data to speed up point-of-care ultrasound adoption across the healthcare system, potentially expanding early disease detection and accelerating the path to treatment. Medo also holds strong partnerships across health systems worldwide, Exo said, including top institutions in Asia and Canada that can help to enable clinical validation and adoption.