DiffPortrait3D: Controllable Diffusion for Zero-Shot Portrait View Synthesis
Authors: Yuming Gu, Hongyi Xu, You Xie, Guoxian Song, Yichun Shi, Di Chang, Jing Yang, Linjie Luo

We present DiffPortrait3D a conditional diffusion model that is capable of synthesizing 3D-consistent photo-realistic novel views from as few as a single in-the-wild portrait. Specifically given a single RGB input we aim to synthesize plausible but consistent facial details rendered from novel camera views with retained both identity and facial expression. In lieu of time-consuming optimization and fine-tuning our zero-shot method generalizes well to arbitrary face portraits with unposed camera views extreme facial expressions and diverse artistic depictions. At its core we leverage the generative prior of 2D diffusion models pre-trained on large-scale image datasets as our rendering backbone while the denoising is guided with disentangled attentive control of appearance and camera pose. To achieve this we first inject the appearance context from the reference image into the self-attention layers of the frozen UNets. The rendering view is then manipulated with a novel conditional control module that interprets the camera pose by watching a condition image of a crossed subject from the same view. Furthermore we insert a trainable cross-view attention module to enhance view consistency which is further strengthened with a novel 3D-aware noise generation process during inference. We demonstrate state-of-the-art results both qualitatively and quantitatively on our challenging in-the-wild and multi-view benchmarks.