ICR SDK Libraries

LEADTOOLS provides fast and accurate Intelligent Character Recognition SDK technology for .NET (C#, VB) and C developers. Leverage the high-level LEADTOOLS ICR toolkit to rapidly develop robust, high-performance recognition applications that save time and money over manual data entry by extracting hand-written text from scanned documents and converting images to text-searchable formats such as PDF, PDF/A, and Microsoft Word.

Unbeatable accuracy

Unparalleled ICR SDK Libraries

Handwritten text has been historically difficult to recognize due to variations in each and every sample set of handwriting. Our optimizations continue to ensure that LEADTOOLS ICR libraries provide unparalleled accuracy by leveraging artificial intelligence and machine learning to power additional technologies such as:

  • Hand printed and cursive in color and bitonal images
  • Automatic image preprocessing to cleanup noise and enhance low-resolution images
  • Spelling dictionary
  • Detect uppercase, lowercase, digits, currency, and punctuation
  • Automatic image segmentation

Extract handwritten text from your data and forms with confidence knowing that LEADTOOLS will return accurate results and maintain document artifacts such as tables, images, signatures, and OMR fields.

Feature-rich ICR SDK

Advanced Handwritten Forms Processing

LEADTOOLS ICR integrates seamlessly with LEADTOOLS Forms Recognition and Processing to extract handwritten information from handwritten filled forms or mix of handwritten and machine printed forms.

ICR can be used standalone as well as be the engine behind higher-level technologies. On its own, programmers can write as few as three lines of code to convert an image to a text-searchable document, offering full page and zonal recognition.

Fast and reliable ICR libraries

Unmatched Speed, Accuracy, and Reliability

The advanced ICR SDK libraries in LEADTOOLS are unbeatably fast, accurate, and reliable. LEAD is continuously optimizing its OCR and ICR libraries to ensure that they are as fast and reliable as possible. This makes the API perfect for applications that range from unattended large volume document batch processing to converting single and multipage documents with manual review. Performance is ensured because the ICR library internally manages multi-threading.

Versatile and robust text recognition capabilities

Versatile Handwritten Text Recognition Capabilities

The LEADTOOLS ICR libraries are capable of handling a wide variety of document variations, including bitonal and color images. At the same time, you have fine grained control with character and numeric filters, multiple voting techniques, and callback functions. After the ICR library has finished processing the image, you gain access to a wealth of information such as character size, location, and confidence values.

In depth reporting

Mixed Zone Recognition

Recognizing that automation and efficiency are at the forefront for developers building OCR solutions, LEAD has mixed mode AutoZone capabilities to extract text from images that contain a mix of machine-printed text, handwritten text, MICR, MRZ, OMR, graphics, and table zones. LEADTOOLS automatically detects and recognizes everything. This powerful combination of OCR, ICR, and other advanced recognition technologies is critical for companies that need to quickly and accurately process various form types regardless of how the data is formatted.

Other recognition libraries

Other Industry-Leading Recognition Libraries

For the past 22 years, LEAD's recognition libraries have been used by thousand of developers and millions of end-users throughout the world. The patented machine learning algorithms that drive these engines bring unparalleled accuracy, speed, and reliability to all of the LEADTOOLS recognition libraries, including the ICR Handwritten Text API library.

Other recognition libraries and components include:

ICR Development Made Easy

Easy to Integrate

LEADTOOLS handles the heavy lifting — eliminating months of R&D, while giving you the best quality and performance available. This leaves you free to focus on other components of your application. Download the evaluation and start coding to get an idea of how much more streamlined your development will be using LEADTOOLS.

Cross platform libraries

ICR SDK Platforms and Programming Interfaces

Projects that use LEADTOOLS ICR libraries can be deployed to Windows devices.

ICR SDK libraries are available for

  • .NET
    • C#, VB, C++/CLI
    • WinForms, ASP.NET
  • C API

Automatic Zone Recognition
Automatically segments an image into various zones which can improve recognition accuracy and efficiency

Manual Zone Recognition
Allow the user to draw and recognize text from specific regions of interest

Zone Types

  • Paragraph
  • Text
  • Numeric
  • Table
  • MICR
  • Graphic

Start Coding With LEADTOOLS ICR


ICR libraries as well as all LEADTOOLS Recognition, Document, Medical, Vector, and Imaging technologies for all development and target platforms.

Download LEADTOOLS Libraries

Online Demo Application that include ICR SDK Libraries


HTML5/JavaScript OCR

Performs OCR with superior accuracy and speed to extract text from images and convert images to various document formats, such as PDF.

  • Individually select pages to OCR
  • Draw zones and return selected text results
  • OCR all pages with automatic zoning