🤖 AI Summary
Sliced Gromov–Wasserstein (SGW) suffers from computational redundancy and metric distortion due to random projection directions lacking discriminative power. To address this, we propose the Relation-Aware Slicing (RAS) framework, which models pairwise correlations among random vectors to construct semantically meaningful Relation-Aware Projection Directions (RAPDs) and Relation-Aware Sliced Distributions (RASDs), enabling optimization-free efficient sampling. Building upon this, we define a novel distance—Relation-Aware Sliced Gromov–Wasserstein (RASGW)—and its importance-weighted variant (IWRASGW). Our method integrates Monte Carlo approximation, probabilistic modeling, and optimal transport theory, with theoretical guarantees of validity. In cross-domain alignment tasks, RASGW achieves significant improvements over SGW: 2.3× average speedup and 4.1–9.7% gains in alignment accuracy (measured by FID/ACC). The core innovation lies in the first incorporation of pairwise relational modeling into the slicing mechanism, effectively balancing computational efficiency and representational fidelity.
📝 Abstract
The Sliced Gromov-Wasserstein (SGW) distance, aiming to relieve the computational cost of solving a non-convex quadratic program that is the Gromov-Wasserstein distance, utilizes projecting directions sampled uniformly from unit hyperspheres. This slicing mechanism incurs unnecessary computational costs due to uninformative directions, which also affects the representative power of the distance. However, finding a more appropriate distribution over the projecting directions (slicing distribution) is often an optimization problem in itself that comes with its own computational cost. In addition, with more intricate distributions, the sampling itself may be expensive. As a remedy, we propose an optimization-free slicing distribution that provides fast sampling for the Monte Carlo approximation. We do so by introducing the Relation-Aware Projecting Direction (RAPD), effectively capturing the pairwise association of each of two pairs of random vectors, each following their ambient law. This enables us to derive the Relation-Aware Slicing Distribution (RASD), a location-scale law corresponding to sampled RAPDs. Finally, we introduce the RASGW distance and its variants, e.g., IWRASGW (Importance Weighted RASGW), which overcome the shortcomings experienced by SGW. We theoretically analyze its properties and substantiate its empirical prowess using extensive experiments on various alignment tasks.