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arXiv 2404.10394cs.CV

Portrait3D:基于金字塔表示与GAN先验的文本引导高质量3D人像生成

Portrait3D: Text-Guided High-Quality 3D Portrait Generation Using Pyramid Representation and GANs Prior

State Key Lab of CAD&CG, Zhejiang University(浙江大学CAD&CG国家重点实验室);Yale University(耶鲁大学);ETH Zürich(苏黎世联邦理工学院);OPPO US Research Center(OPPO美国研究中心)

Yiqian Wu, Hao Xu, Xiangjun Tang, Xien Chen, Siyu Tang, Zhebin Zhang, Chen Li, Xiaogang Jin

AI总结:

针对现有文本到3D人像生成方法仅依赖几何先验导致的雅努斯问题、过平滑等缺陷,提出Portrait3D框架,结合金字塔三网格表示与GAN先验,通过扩散蒸馏和迭代优化生成高质量3D人像。

摘要:

现有的基于神经渲染的文本到3D人像生成方法通常利用人体几何先验和扩散模型获取指导。然而,仅依赖几何信息会引发诸如雅努斯问题、过饱和以及过度平滑等缺陷。我们提出Portrait3D,这是一种新颖的基于神经渲染的框架,具备全新的几何-外观联合先验,可实现文本到3D人像的生成并克服上述问题。为此,我们训练了一个3D人像生成器3DPortraitGAN-Pyramid作为鲁棒先验,该生成器能够生成360°规范3D人像,作为后续基于扩散的生成流程的起点。为缓解大多数3D感知GAN常用的基于特征图的3D表示中高频信息导致的“网格状”伪影,我们在3DPortraitGAN-Pyramid中集成了新颖的金字塔三网格3D表示。为从文本生成3D人像,我们首先将与给定提示对齐的随机生成图像投影到预训练的3DPortraitGAN-Pyramid的潜在空间中,所得潜在编码随后用于合成金字塔三网格。从得到的金字塔三网格出发,我们使用分数蒸馏采样将扩散模型的知识蒸馏到金字塔三网格中。之后,我们利用扩散模型优化3D人像的渲染图像,再将这些优化后的图像作为训练数据进一步优化金字塔三网格,有效消除了色彩不真实和伪影不自然的问题。我们的实验结果表明,Portrait3D能够生成符合提示的、逼真的高质量规范3D人像。

英文摘要:

Existing neural rendering-based text-to-3D-portrait generation methods typically make use of human geometry prior and diffusion models to obtain guidance. However, relying solely on geometry information introduces issues such as the Janus problem, over-saturation, and over-smoothing. We present Portrait3D, a novel neural rendering-based framework with a novel joint geometry-appearance prior to achieve text-to-3D-portrait generation that overcomes the aforementioned issues. To accomplish this, we train a 3D portrait generator, 3DPortraitGAN-Pyramid, as a robust prior. This generator is capable of producing 360° canonical 3D portraits, serving as a starting point for the subsequent diffusion-based generation process. To mitigate the "grid-like" artifact caused by the high-frequency information in the feature-map-based 3D representation commonly used by most 3D-aware GANs, we integrate a novel pyramid tri-grid 3D representation into 3DPortraitGAN-Pyramid. To generate 3D portraits from text, we first project a randomly generated image aligned with the given prompt into the pre-trained 3DPortraitGAN-Pyramid's latent space. The resulting latent code is then used to synthesize a pyramid tri-grid. Beginning with the obtained pyramid tri-grid, we use score distillation sampling to distill the diffusion model's knowledge into the pyramid tri-grid. Following that, we utilize the diffusion model to refine the rendered images of the 3D portrait and then use these refined images as training data to further optimize the pyramid tri-grid, effectively eliminating issues with unrealistic color and unnatural artifacts. Our experimental results show that Portrait3D can produce realistic, high-quality, and canonical 3D portraits that align with the prompt.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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