ndl-lab/ndlocr-lite

NDLOCR-Liteアプリケーションのリポジトリ(ソースコードを含む)NDLOCR‑Lite application repository (including source code)

What it solves

NDLOCR-Lite is a lightweight OCR (Optical Character Recognition) tool designed to convert images of books and magazines into text data. It specifically addresses the need for a high-performance OCR that can run on standard home computers (like laptops) without requiring a dedicated GPU, making digital archiving more accessible on consumer hardware.

How it works

The system combines three primary modules to process images:

  1. Layout Recognition: Uses DEIMv2 (with a ViT-Tiny model distilled from DINOv3) to identify the structure of the page.
  2. Text Recognition: Employs PARSeq to recognize the actual characters within the identified areas.
  3. Reading Order Sorting: Organizes the recognized text into the correct logical sequence.

Models are trained using PyTorch and then converted to ONNX format for efficient execution. The tool can be used via a desktop application (with a screen capture mode) or a command-line interface.

Who it’s for

  • Researchers and archivists digitizing books, magazines, and historical documents.
  • Users who need to perform OCR on Japanese text (including vertical and horizontal writing) without high-end server hardware.
  • Developers looking for a customizable OCR pipeline that supports ONNX models.

Highlights

  • GPU-free operation: Optimized for fast execution on standard Windows, Mac, and Linux laptops.
  • Broad format support: Processes JPG, PNG, TIFF, JP2, BMP, and WebP files.
  • Handwriting support: Enhanced recognition for handwritten characters (as of v1.2).
  • Flexible output: Provides results in XML and JSON formats, with an optional visualization mode to highlight recognized text areas.

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