Tired of the inaccuracies and limitations of traditional OCR? Meet Chandra, an open-source OCR model that not only accurately converts images and PDFs, but also completely preserves the original layout, supporting handwriting, tables, and complex documents. Discover how Chandra can bring new possibilities for document processing to developers and businesses.
Have you ever had this experience: you get a scanned PDF document or image and want to copy the text, but what you paste is a bunch of gibberish? Or the table is completely messed up, and you have to spend half a day manually reorganizing it? This is probably a nightmare that many people have encountered when processing digital documents.
Although traditional Optical Character Recognition (OCR) technology has been around for years, it often falls short when dealing with complex layouts, handwriting, or documents containing a large number of tables and charts. The recognition results are inaccurate, the format is completely lost, and the subsequent manual proofreading and organization are often more tiring than typing a new copy directly.
But what if there is now an OCR model that can not only accurately recognize text, but also perfectly analyze the structure of the document like a smart assistant and convert it into the format you need? Doesn’t that sound appealing?
Today’s protagonist is such a powerful tool - Chandra.
What is Chandra? It’s not just another OCR tool
Chandra is a high-precision open-source OCR model developed by datalab-to. Its core concept is not just to “read” the text in images or PDFs, but to “understand” the entire document’s structure and layout.
Imagine you give Chandra a complex report PDF containing titles, paragraphs, tables, images, and notes. What it gives you back is not a large paragraph of chaotic plain text, but a structured HTML, Markdown, or JSON file. The title is still the title, the table is still a table, and even the positions of the images and captions are marked for you.
This is what makes Chandra different. It is not just a porter of text, but more like a professional typesetter, systematically converting visualized document content into machine-readable structured data.
The magic of Chandra: not just talk
Chandra’s powerful functions come from its deep support for various document elements. Let’s see what it’s really capable of.
handwritten-text-recognition, form-reconstruction, table-extraction
Amazing handwriting recognition capabilities
The recognition of handwriting has always been a major challenge for OCR technology. Everyone’s writing style is different, and cursive and connected writing are commonplace. Chandra performs well in this area and has good support for common handwritten content. Whether it’s meeting minutes, handwritten notes, or questionnaires, it can greatly improve the accuracy of recognition and reduce the trouble of manual proofreading.
Accurate form reconstruction
Processing forms is another common pain point. Traditional OCR may only be able to extract the text on the form, but it is difficult to grasp the corresponding relationship between fields and options (especially checkboxes). Chandra can accurately reconstruct the form structure, including text fields and checked checkboxes, which is a great boon for application scenarios such as automated data entry and questionnaire analysis.
Complex tables and mathematical formulas? No problem!
Chandra can also handle complex tables and mathematical formulas commonly found in financial reports, academic papers, or technical manuals. It can maintain the row and column structure of the table and convert it into a clean Markdown or HTML format, and can even handle LaTeX mathematical equations. This means that you no longer have to worry about organizing table data.
Images and charts can also be intelligently extracted
In addition to text, a document usually contains many images and charts. Chandra can not only extract these visual elements from the document, but also intelligently identify the captions of the images and associate them with the images themselves to provide complete structured data.
Supports over 40 languages with high deployment flexibility
In today’s globalized world, processing multilingual documents is a basic requirement. Chandra supports more than 40 languages, covering the world’s major language families, making its application range even wider.
In addition, it provides two flexible deployment modes:
- Local mode (Local via HuggingFace): For users who value data privacy or need to run in a local environment, they can run the model directly on their own machines through HuggingFace.
- Remote mode (Remote via vLLM server): If you need high-performance inference or want to integrate it into a cloud service, you can also deploy the model on a vLLM server and call it through an API.
This flexibility allows developers to choose the most suitable deployment method according to their own needs and resources.
How to get started with Chandra?
Chandra is an open source project, which means you can use it for free and even contribute to it. The development team has placed all resources on a public platform:
- GitHub repository: https://github.com/datalab-to/chandra You can find the complete source code, installation instructions, and usage examples here.
- HuggingFace model page: https://huggingface.co/datalab-to/chandra If you want to quickly experience or download a pre-trained model, HuggingFace is your best starting point.
Conclusion: The future of document processing has arrived
In summary, Chandra is not just an OCR model, it is more like a complete document intelligent analysis solution. By combining visual layout information with text content, it opens a new door for automated document processing, data extraction, and knowledge management.
Whether you are a data scientist who needs to process a large number of documents, an engineer who wants to develop smart document applications, or just want to find a smarter way to organize digital data, Chandra is definitely worth a try.
Frequently Asked Questions (FAQ)
Q1: Is there a fee to use Chandra? A: Chandra is an open source project and is free in itself. You only need to bear the hardware costs required to run the model (such as a local GPU or cloud server fees).
Q2: What is the difference between Chandra and other open source OCR models such as Tesseract or EasyOCR? A: The biggest difference lies in Chandra’s understanding of “document structure”. Tesseract and EasyOCR mainly focus on text recognition itself, and their ability to structure output for complex layouts, tables, and forms is limited. Chandra’s core is to retain complete document layout information, and the output is structured HTML/Markdown/JSON, not just plain text.
Q3: Do I need a strong technical background to use Chandra?
A: For developers, Chandra provides clear documentation and examples, making it relatively easy to get started. Through HuggingFace’s transformers library, you can start using it with just a few lines of Python code. For non-technical users, some basic command line or Python environment setup knowledge may be required.


