EpiAgent: An Agent-Centric System for Ancient Inscription Restoration
Authors: Shipeng Zhu, Ang Chen, Na Nie, Pengfei Fang, Min-Ling Zhang, Hui Xue
Organizations: School of Computer Science and Engineering, Southeast University, China · Key Laboratory of New Generation Artificial Intelligence Technology and Its Interdisciplinary Applications (Southeast University), Ministry of Education, China · Nanjing University Museum, Nanjing University, China · The China Centre for Linguistic and Strategic Studies, Nanjing University, China · Key Laboratory of Computer Network and Information Integration (Southeast University), Ministry of Education, China
Ancient inscriptions, as repositories of cultural memory, have suffered from centuries of environmental and human-induced degradation. Restoring their intertwined visual and textual integrity poses one of the most demanding challenges in digital heritage preservation. However, existing AI-based approaches often rely on rigid pipelines, struggling to generalize across such complex and heterogeneous real-world degradations. Inspired by the skill-coordinated workflow of human epigraphers, we propose EpiAgent, an agent-centric system that formulates inscription restoration as a hierarchical planning problem. Following an Observe-Conceive-Execute-Reevaluate paradigm, an LLM-based central planner orchestrates collaboration among multimodal analysis, historical experience, specialized restoration tools, and iterative self-refinement. This agent-centric coordination enables a flexible and adaptive restoration process beyond conventional single-pass methods. Across real-world degraded inscriptions, EpiAgent achieves superior restoration quality and stronger generalization compared to existing methods. Our work marks an important step toward expert-level agent-driven restoration of cultural heritage. The code is available at https://github.com/blackprotoss/EpiAgent.
Figures & tables
Figure 1: Illustration of the restored ancient inscription samples.
Figure 2: Illustration of the EpiAgent framework, which mimics the restoration workflow of human epigraphers.
Figure 3: Illustration of the workflow of EpiAgent. The “MLLM”, “LRM”, “DAM”, “CLM”, and “CC” denote Multimodal Large Language Model, Layout Rectification Module, Degradation Assessment Model, Corrective Language Model, and Chinese Corpora, respectively.
Figure 4: (a) Process of Specialized Restoration Tools; (b) Details of Multi-perspective Evaluation.
Figure 5: Restoration results of different methods on degraded inscription images. (a)-(b) are from Testing Set S, (c)-(d) belong to Testing Set R-I, and (e)-(f) belong to Testing Set R-II. The red borders denote the degraded patches and the restored patches by competing methods, while the green counterparts denote the ground-truth text and the restored patches by EpiAgent.
Figure 6: Exemplary comparison between different tool invocation sequences faced with (a) severely degraded (L3) and (b) slightly degraded (L1) character blocks. The green lines mark the optimal restoring sequence.
Analysis Module
1-NED ↑
MLLM
CLM
RAG
Set S
Set R-I
Set R-II
✓
✗
✗
0.6481
0.5509
0.4336
✓
✓
✗
0.9211
0.8759
0.8486
✓
✓
✓
0.9742
0.9694
0.9606
Table 3: Ablation studies of the analysis modules used in the Observation stage. The best and the second-best results are highlighted and underlined .
Figure 7: Comparison of restoration outcomes across different tools. (a)-(d), (e)-(h), (i)-(l) correspond slightly, middely, and severely degraded character. Red and green borders indicate the restorations preferred by EpiAgent and human experts, respectively, while purple borders indicate cases where their choices coincide.
Figure 8: Quantitative comparison of restoration time and CLIP-IQA with and without reflective experience.
Ancient inscriptions frequently suffer missing or corrupted regions from fragmentation, erosion, or other damage, hindering reading, and analysis. We review prior image restoration methods and their applicability to inscription image recovery, then introduce MESA (Multi-Exemplar, Style-Aware) -an image-level restoration method that uses well-preserved exemplar inscriptions (from the same epigraphic monument, material, or similar letterforms) to guide reconstruction of damaged text. MESA encodes VGG19 convolutional features as Gram matrices to capture exemplar texture, style, and stroke structure; for each neural network layer it selects the exemplar minimizing Mean-Squared Displacement (MSD) to the damaged input. Layer-wise contribution weights are derived from Optical Character Recognition-estimated character widths in the exemplar set to bias filters toward scales matching letter geometry, and a training mask preserves intact regions so synthesis is restricted to damaged areas. We also summarize prior network architectures and exemplar and single-image synthesis, inpainting, and Generative Adversarial Network (GAN) approaches, highlighting limitations that MESA addresses. Comparative experiments demonstrate the advantages of MESA. Finally, we provide a practical roadmap for choosing restoration strategies given available exemplars and metadata.
Vasileios Toulatzis, Sofia Theodoridou, Ioannis Fudos
Ancient script image restoration is a fundamental problem in computer vision, as it directly affects the reliable analysis and interpretation of historical documents and inscriptions. Ashokan Brahmi is an ancient script extensively used during the reign of Emperor Ashoka in the 3rd century BC, primarily for inscriptions in Prakrit. These inscriptions, including major and minor rock and pillar edicts, constitute a valuable yet largely unexplored source of data for computational analysis. The degraded nature of inscription imagery and the lack of standardized digital resources pose significant challenges for automated processing. We present an end-to-end AI-based framework for understanding ancient inscriptions that encompasses image enhancement, optical character recognition (OCR), transliteration, and neural machine translation (NMT). The proposed pipeline processes low-quality images captured directly from stone inscriptions, performs image restoration and Brahmi script character recognition, maps the recognized characters to the Roman script, and finally translates the resulting Prakrit text into English. We also introduce two new datasets: (i) InscriptionOCR Dataset: the largest publicly usable digital OCR dataset for Brahmi script to date, consisting of over 200,000 character images across about 600 classes, and (ii) a bilingual Prakrit-English parallel corpus comprising over 2,000 sentence pairs for NMT. We believe that the proposed framework and datasets will facilitate future research in ancient script analysis, low-resource OCR, and digital epigraphy.
Jaidev Sanjay Khalane, Akbar Ali, V. N. Prabhakar +1
Indian Institute of Technology Gandhinagar, India.
Full-page blind restoration of historical Manchu manuscripts is challenging due to scarce annotations, unknown degradation regions, and fragile connected strokes. Generic restoration models may improve visual quality but often modify intact content, leading to over-restoration. We propose SAGE-Restore (Stroke-Aware Gated rEstoration), a selective restoration framework that first assesses where restoration is needed and then uses this assessment to guide restoration candidate generation and pixel-level selection. Its encoder predicts patch-level repair probabilities from complementary appearance and stroke-structural cues to condition restoration candidate generation, while the corresponding repair logits are refined into a pixel-level soft gate that selectively controls where the restoration candidate is applied. We further introduce a fidelity-aware evaluation protocol that jointly measures degraded-region recovery, intact-content preservation, and their balance. SAGE-Restore achieves the highest R-Recovery (0.463) and RFS (0.626), while maintaining high U-Fidelity (0.968), demonstrating an effective balance between restoration and content preservation.
Mingqiu Liang, Dongdong Wang, Siyang Lu +2
School of Computer Science and Technology, Beijing Jiaotong University, Beijing, China · College of Design, Construction, and Planning, University of Florida, Gainesville, FL, USA · School of Japanese Studies, Dalian University of Foreign Languages, Dalian, China