OCR Library in Node.js (JavaScript)

Optical Character Recognition (OCR) is the process of taking image-based versions of characters and converting them into machine encoded text.This enables your application to recognize and convert characters from scanned images or image-based documents into machine-readable, searchable text.

This capability is essential for transforming static visual content—such as scanned books, photos of documents, or handwritten forms—into usable digital text that can be indexed, selected, copied, or searched.

Some popular use cases include:

• Data entry for business documents, e.g. Cheque, passport, invoice, bank statement and receipt
• Automatic number plate recognition from a photo
• Automatic extraction of form documents with text fields
• Extracting business card information into a contact list
• More quickly make textual versions of printed documents, e.g. book scanning
• Make electronic images of printed documents searchable
• Assistive technology for blind and visually impaired users
• Making scanned documents searchable by converting them to searchable PDFs

The ApryseServerSDK offers a downloadable OCR Module as an optional add-on utility in order to use OCR with the SDK. It is currently available on Windows, Linux, and macOS.

The default OCR Module included with the Apryse SDK delivers strong recognition capabilities across a wide range of document types. For advanced layout scenarios—such as pages with multiple disconnected text regions like magazine covers or CAD drawings—you can optionally use the IRIS OCR Module, which may provide improved accuracy and layout interpretation. The IRIS module is available as an additional add-on for Windows and Linux platforms.

Using an OCR module, the SDK can create searchable and selectable text from images or PDFs, producing either a PDF with selectable text, or outputting just the text position data in reusable JSON or XML form.

Once integrated, the OCR Module enables the SDK to generateSearchable PDFs with selectabletext layers

The module takes advantage of pdftron.PDF.Convert.ToPdf internally and accepts multiple image formats, as well as PDFs with only raster images. The result quality depends on image supplied. The ideal image is greyscale with resolution in the vicinity of 300 DPI.

OCR workflow
In this section, we showcase the potential OCR workflow.