🤖 AI Summary
Existing methods for image and video object manipulation struggle to simultaneously preserve background content, maintain geometric consistency across viewpoints, and offer fine-grained user control. This work proposes Ctrl&Shift, an end-to-end diffusion framework that decomposes manipulation into two stages—object removal followed by camera-pose-guided reference-based inpainting—enabling geometrically consistent editing within a unified diffusion process without explicit 3D modeling. By integrating explicit camera pose control, reference-guided inpainting, and a multi-task, multi-stage training strategy, the method effectively disentangles background, identity, and pose signals. This design preserves generalization to real-world scenes while supporting precise geometric manipulation. Experiments demonstrate that Ctrl&Shift significantly outperforms existing geometry-based and diffusion-based approaches in terms of generation fidelity, viewpoint consistency, and user controllability.
📝 Abstract
Object-level manipulation, relocating or reorienting objects in images or videos while preserving scene realism, is central to film post-production, AR, and creative editing. Yet existing methods struggle to jointly achieve three core goals: background preservation, geometric consistency under viewpoint shifts, and user-controllable transformations. Geometry-based approaches offer precise control but require explicit 3D reconstruction and generalize poorly; diffusion-based methods generalize better but lack fine-grained geometric control. We present Ctrl&Shift, an end-to-end diffusion framework to achieve geometry-consistent object manipulation without explicit 3D representations. Our key insight is to decompose manipulation into two stages, object removal and reference-guided inpainting under explicit camera pose control, and encode both within a unified diffusion process. To enable precise, disentangled control, we design a multi-task, multi-stage training strategy that separates background, identity, and pose signals across tasks. To improve generalization, we introduce a scalable real-world dataset construction pipeline that generates paired image and video samples with estimated relative camera poses. Extensive experiments demonstrate that Ctrl&Shift achieves state-of-the-art results in fidelity, viewpoint consistency, and controllability. To our knowledge, this is the first framework to unify fine-grained geometric control and real-world generalization for object manipulation, without relying on any explicit 3D modeling.