Learning Joint ID-Textual Representation for ID-Preserving Image Synthesis
Zichuan Liu, Liming Jiang, Qing Yan, Yumin Jia, Hao Kang, Xin Lu
TL;DR
This work introduces FaceCLIP, a multi-modal encoder that learns a joint identity-text representation to condition ID-preserving portrait synthesis, avoiding adapters and enabling full diffusion-model adaptation. By aligning the joint embedding with face, text, and image spaces and fusing identity and semantic cues via a Fusion Module, FaceCLIP delivers stronger identity preservation and semantic alignment when integrated with Stable Diffusion XL as FaceCLIP-SDXL. The approach demonstrates state-of-the-art results on identity similarity and perceptual quality across internal and public portrait datasets, supported by zero-shot text alignment, identity clustering analyses, and user studies. The method offers a scalable, end-to-end framework for controllable, high-fidelity portrait synthesis with robust identity fidelity and semantic controllability.
Abstract
We propose a novel framework for ID-preserving generation using a multi-modal encoding strategy rather than injecting identity features via adapters into pre-trained models. Our method treats identity and text as a unified conditioning input. To achieve this, we introduce FaceCLIP, a multi-modal encoder that learns a joint embedding space for both identity and textual semantics. Given a reference face and a text prompt, FaceCLIP produces a unified representation that encodes both identity and text, which conditions a base diffusion model to generate images that are identity-consistent and text-aligned. We also present a multi-modal alignment algorithm to train FaceCLIP, using a loss that aligns its joint representation with face, text, and image embedding spaces. We then build FaceCLIP-SDXL, an ID-preserving image synthesis pipeline by integrating FaceCLIP with Stable Diffusion XL (SDXL). Compared to prior methods, FaceCLIP-SDXL enables photorealistic portrait generation with better identity preservation and textual relevance. Extensive experiments demonstrate its quantitative and qualitative superiority.
