Identity-Preserving Text-to-Video Generation by Frequency Decomposition
Authors: name: Shenghai Yuan, name: Jinfa Huang, name: Xianyi He, name: Yunyuan Ge, name: Yujun Shi, name: Liuhan Chen, name: Jiebo Luo, name: Li Yuan

Identity-preserving text-to-video (IPT2V) generation aims to create
high-fidelity videos with consistent human identity. It is an important task in
video generation but remains an open problem for generative models. This paper
pushes the technical frontier of IPT2V in two directions that have not been
resolved in literature: (1) A tuning-free pipeline without tedious case-by-case
finetuning, and (2) A frequency-aware heuristic identity-preserving DiT-based
control scheme. We propose ConsisID, a tuning-free DiT-based controllable IPT2V
model to keep human identity consistent in the generated video. Inspired by
prior findings in frequency analysis of diffusion transformers, it employs
identity-control signals in the frequency domain, where facial features can be
decomposed into low-frequency global features and high-frequency intrinsic
features. First, from a low-frequency perspective, we introduce a global facial
extractor, which encodes reference images and facial key points into a latent
space, generating features enriched with low-frequency information. These
features are then integrated into shallow layers of the network to alleviate
training challenges associated with DiT. Second, from a high-frequency
perspective, we design a local facial extractor to capture high-frequency
details and inject them into transformer blocks, enhancing the model's ability
to preserve fine-grained features. We propose a hierarchical training strategy
to leverage frequency information for identity preservation, transforming a
vanilla pre-trained video generation model into an IPT2V model. Extensive
experiments demonstrate that our frequency-aware heuristic scheme provides an
optimal control solution for DiT-based models. Thanks to this scheme, our
ConsisID generates high-quality, identity-preserving videos, making strides
towards more effective IPT2V.