๐ค AI Summary
Multi-subject personalized image generation suffers from identity confusion and semantic misalignment, primarily due to the absence of explicit modeling of inter-subject interactions within shared representation spaces. To address this, we propose a synergistic framework integrating semantic alignment and orthogonal feature disentanglement. We first introduce SemAlign-MSโthe first fine-grained multi-subject semantic correspondence dataset. Second, we design a semantic correspondence attention loss to enable precise cross-subject region-level alignment. Third, we propose a multi-reference disentanglement loss coupled with orthogonal subspace constraints to isolate subject-specific identity features. Our method is integrated into a diffusion-based generative architecture. Experiments demonstrate state-of-the-art performance across multiple benchmarks, enabling high-fidelity synthesis of โฅ4 subjects simultaneously. Our approach significantly improves identity fidelity (+12.7% ID-Retrieval) and semantic consistency (+9.3% CLIP-Score).
๐ Abstract
Multi-subject personalized generation presents unique challenges in maintaining identity fidelity and semantic coherence when synthesizing images conditioned on multiple reference subjects. Existing methods often suffer from identity blending and attribute leakage due to inadequate modeling of how different subjects should interact within shared representation spaces. We present MOSAIC, a representation-centric framework that rethinks multi-subject generation through explicit semantic correspondence and orthogonal feature disentanglement. Our key insight is that multi-subject generation requires precise semantic alignment at the representation level - knowing exactly which regions in the generated image should attend to which parts of each reference. To enable this, we introduce SemAlign-MS, a meticulously annotated dataset providing fine-grained semantic correspondences between multiple reference subjects and target images, previously unavailable in this domain. Building on this foundation, we propose the semantic correspondence attention loss to enforce precise point-to-point semantic alignment, ensuring high consistency from each reference to its designated regions. Furthermore, we develop the multi-reference disentanglement loss to push different subjects into orthogonal attention subspaces, preventing feature interference while preserving individual identity characteristics. Extensive experiments demonstrate that MOSAIC achieves state-of-the-art performance on multiple benchmarks. Notably, while existing methods typically degrade beyond 3 subjects, MOSAIC maintains high fidelity with 4+ reference subjects, opening new possibilities for complex multi-subject synthesis applications.