What Is Wrong with Synthetic Data for Scene Text Recognition? A Strong Synthetic Engine with Diverse Simulations and Self-Evolution

Large-scale and categorical-balanced text data is essential for training effective Scene Text Recognition (STR) models, which is hard to achieve when collecting real data. Synthetic data offers a cost-effective and perfectly labeled alternative. However, its performance often lags behind, revealing a significant domain gap between real and current synthetic data. In this work, we systematically analyze mainstream rendering-based synthetic datasets and identify their key limitations: insufficient diversity in corpus, font, and layout, which restricts their realism in complex scenarios. To address these issues, we introduce UnionST, a strong data engine synthesizes text covering a union of challenging samples and better aligns with the complexity observed in the wild. We then construct UnionST-S, a large-scale synthetic dataset with improved simulations in challenging scenarios. Furthermore, we develop a self-evolution learning (SEL) framework for effective real data annotation. Experiments show that models trained on UnionST-S achieve significant improvements over existing synthetic datasets. They even surpass real-data performance in certain scenarios. Moreover, when using SEL, the trained models achieve competitive performance by only seeing 9% of real data labels.

TextSSR: Diffusion-based Data Synthesis for Scene Text Recognition

Scene text recognition (STR) suffers from the challenges of either less realistic synthetic training data or the difficulty of collecting sufficient high-quality real-world data, limiting the effectiveness of trained STR models. Meanwhile, despite producing holistically appealing text images, diffusion-based text image generation methods struggle to generate accurate and realistic instance-level text on a large scale. To tackle this, we introduce TextSSR: a novel framework for Synthesizing Scene Text Recognition data via a diffusion-based universal text region synthesis model. It ensures accuracy by focusing on generating text within a specified image region and leveraging rich glyph and position information to create the less complex text region compared to the entire image. Furthermore, we utilize neighboring text within the region as a prompt to capture real-world font styles and layout patterns, guiding the generated text to resemble actual scenes. Finally, due to its prompt-free nature and capability for character-level synthesis, TextSSR enjoys a wonderful scalability and we construct an anagram-based TextSSR-F dataset with 0.4 million text instances with complexity and realism. Experiments show that models trained on added TextSSR-F data exhibit better accuracy compared to models trained on 4 million existing synthetic data. Moreover, its accuracy margin to models trained fully on a real-world dataset is less than 3.7%, confirming TextSSR's effectiveness and its great potential in scene text image synthesis. Our code is available at https://github.com/YesianRohn/TextSSR.

Cross-Modality Safety Alignment

As Artificial General Intelligence (AGI) becomes increasingly integrated into various facets of human life, ensuring the safety and ethical alignment of such systems is paramount. Previous studies primarily focus on single-modality threats, which may not suffice given the integrated and complex nature of cross-modality interactions. We introduce a novel safety alignment challenge called Safe Inputs but Unsafe Output (SIUO) to evaluate cross-modality safety alignment. Specifically, it considers cases where single modalities are safe independently but could potentially lead to unsafe or unethical outputs when combined. To empirically investigate this problem, we developed the SIUO, a cross-modality benchmark encompassing 9 critical safety domains, such as self-harm, illegal activities, and privacy violations. Our findings reveal substantial safety vulnerabilities in both closed- and open-source LVLMs, such as GPT-4V and LLaVA, underscoring the inadequacy of current models to reliably interpret and respond to complex, real-world scenarios.