Structure-Level Disentangled Diffusion for Few-Shot Chinese Font Generation

TL;DR

Based on theoretical validation of disentanglement effectiveness, a parameter-efficient fine-tuning strategy that updates only the style-related modules is introduced that allows the model to better adapt to new styles while avoiding overfitting to the reference images'content.

Abstract

Few-shot Chinese font generation aims to synthesize new characters in a target style using only a handful of reference images. Achieving accurate content rendering and faithful style transfer requires effective disentanglement between content and style. However, existing approaches achieve only feature-level disentanglement, allowing the generator to re-entangle these features, leading to content distortion and degraded style fidelity. We propose the Structure-Level Disentangled Diffusion Model (SLD-Font), which receives content and style information from two separate channels. SimSun-style images are used as content templates and concatenated with noisy latent features as the input. Style features extracted by a CLIP model from target-style images are integrated via cross-attention. Additionally, we train a Background Noise Removal module in the pixel space to remove background noise in complex stroke regions. Based on theoretical validation of disentanglement effectiveness, we introduce a parameter-efficient fine-tuning strategy that updates only the style-related modules. This allows the model to better adapt to new styles while avoiding overfitting to the reference images' content. We further introduce the Grey and OCR metrics to evaluate the content quality of generated characters. Experimental results show that SLD-Font achieves significantly higher style fidelity while maintaining comparable content accuracy to existing state-of-the-art methods.

Figures (6)

• Figure 1: Existing methods, as illustrated in (a), are typically built upon a framework that achieves feature-level disentanglement. In contrast, our approach achieves structure-level disentanglement as shown in (b), yielding more robust content preservation and style controllability. As demonstrated in (c), our method produces Chinese characters with noticeably higher visual quality.
• Figure 2: Both source and target images are encoded into the latent space through a VAE encoder. Gaussian noise is added to the latent target representation during diffusion, producing a noisy latent image that is concatenated with the source and fed into the U-Net. Content and style are disentangled within the U-Net: content components capture structural patterns from the source image, while style components receive CLIP-extracted features from multiple style reference images and inject them via cross-attention. The U-Net output is decoded by the VAE, binarized, and refined in pixel space using the BNR module to produce clean and accurate glyphs.
• Figure 3: The VAE output shows background noise in dense stroke areas, which is visible in the grayscale histogram. The BNR module effectively removes the noise.
• Figure 4: Results of gradient analysis. Style-related parameters are more sensitive to unseen styles, while content-related parameters are more sensitive to unseen content.
• Figure 5: Visualization of Chinese character generation results under SCUF and UCUF settings, illustrating two fonts for each of six representative style characteristics. Problematic generations are highlighted with red circles.