Viewpoint Consistency in 3D Generation via Attention and CLIP Guidance

Despite recent advances in text-to-3D generation techniques, current methods often suffer from geometric inconsistencies, commonly referred to as the Janus Problem. This paper identifies the root cause of the Janus Problem: viewpoint generation bias in diffusion models, which creates a significant gap between the actual generated viewpoint and the expected one required for optimizing the 3D model. To address this issue, we propose a tuning-free approach called the Attention and CLIP Guidance (ACG) mechanism. ACG enhances desired viewpoints by adaptively controlling cross-attention maps, employs CLIP-based view-text similarities to filter out erroneous viewpoints, and uses a coarse-to-fine optimization strategy with staged prompts to progressively refine 3D generation. Extensive experiments demonstrate that our method significantly reduces the Janus Problem without compromising generation speed, establishing ACG as an efficient, plug-and-play component for existing text-to-3D frameworks.

Manipulated Face Detector: Joint Spatial and Frequency Domain Attention Network

Face manipulation methods develop rapidly in recent years, which can generate high quality manipulated face images. However, detection methods perform not well on data produced by state-of-the-art manipulation methods, and they lack of generalization ability. In this paper, we propose a novel manipulated face detector, which is based on spatial and frequency domain combination and attention mechanism. Spatial domain features are extracted by facial semantic segmentation, and frequency domain features are extracted by Discrete Fourier Transform. We use features both in spatial domain and frequency domain as inputs in proposed model. And we add attention-based layers to backbone networks, in order to improve its generalization ability. We evaluate proposed model on several datasets and compare it with other state-of-the-art manipulated face detection methods. The results show our model performs best on both seen and unseen data.