README.md

---
license: apache-2.0
library_name: transformers
pipeline_tag: image-text-to-text
tags:
- ocr
- document-parsing
- document-understanding
- multimodal
- markdown
- tables
- formulas
- vllm
---

# OvisOCR

<p align="center">
  <img src="https://cdn-uploads.huggingface.co/production/uploads/658a8a837959448ef5500ce5/vRCIu5QD8VuIJolkC_ZHQ.png" alt="Ovis" width="30%" />
</p>

## Introduction

We introduce **OvisOCR**, a lightweight end-to-end multimodal large language model (MLLM) tailored for high-fidelity document parsing. Unlike conventional **Crop-OCR-Merge** systems that rely on layout detection, localized cropping, specialized recognizers, and heuristic merging, OvisOCR directly maps full-page document images into structured Markdown outputs.

OvisOCR is designed for information-dense documents containing natural language text, tables, mathematical formulas, figures, and complex layouts. It preserves fine-grained textual fidelity while maintaining global document structure and human reading order. With only **1.3B parameters**, OvisOCR achieves outstanding overall performance on OmniDocBench v1.5.

<p align="center">
  <img src="https://cdn-uploads.huggingface.co/production/uploads/658a8a837959448ef5500ce5/GRIIcBHcv4Ou0iglqxHxa.png" alt="benchmark" width="100%" />
</p>

## Key Features

- **Strictly End-to-End Document Parsing**  
  OvisOCR directly maps full-page visual signals to structured Markdown without localized slicing, layout-dependent recognition, or post-hoc merging. This streamlined paradigm reduces error propagation and improves global serialization consistency.

- **Synergistic Data Construction**  
  Our data construction pipeline builds high-quality supervision by combining the strengths of a specialized OCR engine and a general-purpose MLLM. The specialized perceiver supplies dense local evidence, while the general reasoner checks for hallucinations, content completeness, table validity, formula syntax, and logical reading order.

- **Multi-Granularity Alignment**  
  OvisOCR uses element-aware optimization for heterogeneous document constituents. Text, tables, and formulas are optimized with tailored reward signals, including edit-distance-based text fidelity, TEDS-based table similarity, and CDM-based formula visual correctness.

- **Strong Document Parsing Capability with Compact Scale**  
  With only 1.3B parameters, OvisOCR achieves outstanding performance on OmniDocBench v1.5, surpassing strong specialized parsers, large general MLLMs, and traditional pipeline tools.

<p align="center">
  <img src="https://cdn-uploads.huggingface.co/production/uploads/658a8a837959448ef5500ce5/uXnTqnEQ1Ux5Oy8LEYw6U.png" alt="OvisOCR" width="100%" />
</p>

## Inference

```bash
pip install "vllm==0.18.1" pillow
```
```python
from PIL import Image
from vllm import LLM, SamplingParams


class OvisOCRParser:
    def __init__(self, model_name_or_path: str):
        self.model = LLM(
            model=model_name_or_path,
            tensor_parallel_size=1,
            trust_remote_code=True,
            gpu_memory_utilization=0.8,
        )

        prompt = 'Extract all readable content from the image in natural human reading order and output the result as a single Markdown document. For charts or images, represent them using an HTML image tag: <' + 'img src="images/bbox_{left}_{top}_{right}_{bottom}.jpg" />, where left, top, right, bottom are bounding box coordinates scaled to [0, 1000). Format formulas as LaTeX. Format tables as HTML: <table>...</table>. Transcribe all other text as standard Markdown. Preserve the original text without translation or paraphrasing.'
        self.prompt = self.model.get_tokenizer().apply_chat_template(
            [{"role": "user", "content": f"<image>\n{prompt}"}],
            tokenize=False,
            add_generation_prompt=True,
            enable_thinking=False
        )

        self.sampling_params = SamplingParams(
            max_tokens=16384,
            temperature=0.0,
        )

    def _clean_truncated_repeats(
        self,
        text: str,
        min_text_len: int = 8000,
        max_period: int = 200,
        min_period: int = 1,
        min_repeat_chars: int = 100,
        min_repeat_times: int = 5
    ) -> str:
        n = len(text)
        if n < min_text_len:
            return text

        max_period = min(max_period, n - 1)
        for unit_len in range(min_period, max_period + 1):
            if text[n - 1] != text[n - 1 - unit_len]:
                continue

            match_len = 1
            idx = n - 2
            while idx >= unit_len and text[idx] == text[idx - unit_len]:
                match_len += 1
                idx -= 1

            total_len = match_len + unit_len
            repeat_times = total_len // unit_len
            tail_len = total_len % unit_len

            if repeat_times >= min_repeat_times and total_len >= min_repeat_chars:
                return text[: n - total_len + unit_len] + text[n - tail_len:]

        return text

    def parse(self, images: list[Image.Image], filter_imgtags: bool = True) -> list[str]:
        vllm_inputs = [
            {
                "prompt": self.prompt,
                "multi_modal_data": {"image": image},
                "mm_processor_kwargs": {
                    "images_kwargs": {
                        "min_pixels": 448 * 448,
                        "max_pixels": 2880 * 2880,
                    }
                }
            }
            for image in images
        ]

        outputs = self.model.generate(vllm_inputs, self.sampling_params)

        markdowns = []
        for output in outputs:
            text = output.outputs[0].text.strip()
            if filter_imgtags:
                text = "\n\n".join(
                    block
                    for block in text.split("\n\n")
                    if not block.strip().startswith('<img src="images/bbox_')
                )
            markdowns.append(self._clean_truncated_repeats(text))

        return markdowns


if __name__ == "__main__":
    parser = OvisOCRParser("AIDC-AI/OvisOCR")
    images = [Image.open("test1.jpg"), Image.open("test2.jpg")]
    markdowns = parser.parse(images)
    print(markdowns[0])
```

## Citation

If you find OvisOCR useful, please consider citing our paper:

```bibtex
@inproceedings{jiang2026ovisocr,
  title = {{OvisOCR}: End-to-End Document Parsing via Aligning Specialized Perception with General Reasoning},
  author = {Jiang, Jun-Peng and Lu, Shiyin and Ji, An-Yang and Li, Yinglun and Chen, Qing-Guo and Xu, Zhao and Luo, Weihua and Zhang, Kaifu and Zhan, De-Chuan and Ye, Han-Jia},
  booktitle = {Proceedings of the 43rd International Conference on Machine Learning},
  series = {Proceedings of Machine Learning Research},
  volume = {306},
  address = {Seoul, South Korea},
  publisher = {PMLR},
  year = {2026}
}
```

## License

This project is licensed under the [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0.txt) (SPDX-License-Identifier: Apache-2.0).

## Disclaimer

We used automated filtering and quality-assurance procedures during data construction to reduce parsing errors such as repeated hallucinations, incomplete content, invalid table/formula structures, and reading-order inconsistencies. Due to the diversity and complexity of real-world documents, OvisOCR may still produce incorrect or incomplete outputs. Please manually verify results in critical applications.