WritePad® Handwriting Recognition SDK

For Android, iOS, Windows, Windows Phone, Xamarin

Accurate, fast, compact, easy to use, multilingual, multiplatform handwriting recognition technology for mobile and desktop computers

Copyright © 1997-2020 PhatWare® Corp. All rights reserved.

This SDK is distributed under the GPL v 3.0 license.

If you are working on an Open Source project, you can access the WRITEPAD Handwriting Recognition Engine source code under GPL v.3.0 license here: https://github.com/phatware/WritePad-Handwriting-Recognition-Engine

SDK Overview

WritePad® is a natural, style, writer and lexicon independent multilingual handwriting recognition technology. WritePad SDK enables natural handwriting input in third party applications on pen and/or touch enabled mobile devices. The SDK includes:

• WritePad handwriting recognition engine in object code and dictionaries support following languages English (UK and US), French, German, Dutch, Danish, Indonesian, Italian, Portuguese (Brazilian and European), Norwegian, Finish, Swedish, and Spanish. Engine is compatible with the user-specified platform.
• iOS: WritePad SDK static library supports iOS 8.0 or later. The sample code is for iOS 11 (Swift 5) or later and requires Xcode 10.2 or later.
• Android: WritePad SDK static libraries support Android 4.0 or later for arm64-v8a, armeabi, armeabi-v7a, mips, mips64, x86, and x86_64 CPUs.
• Windows: WritePad SDK DLLs for Windows and Windows Phone (x86, x64, and ARM CPUs), metro-style (Windows/Windows Phone 8.1+), and desktop C# WPF sample (Windows 10+, .NET framework 4.6). Sample code requires Visual Studio 2015 Community Edition or higher.
• Xamarin (Android and iOS): WritePad SDK static libraries support Android 4.0 or later for arm64-v8a, armeabi, armeabi-v7a, mips, mips64, x86, and x86_64 CPUs and static library supports iOS 10.0 or later. Sample code is provided for Android and iOS. Requires Microsoft Visual Studio 8 or later Indie or Business edition.
• Header files with definition of API calls and structures
• Developer's Guide in PDF
• Sample source code that demonstrates how to use the WritePad SDK in an iOS application.

WritePad SDK features

• Recognizes natural handwritten text in a variety of handwriting styles: cursive (script), PRINT, and MIXed (cursive/print).
• Recognizes dictionary words from its main or user-defined dictionary, as well as non-dictionary words, such as names, numbers and mixed alphanumeric combinations.
• Provides automatic segmentation of handwritten text into words and automatically differentiates between vocabulary and non-vocabulary words, and between words and arbitrary alphanumeric strings
• Does not require a user to train the software and allows for most users to achieve high accuracy right "out of the box".
• Reliably recognizes handwriting in 12 languages, including English (US, UK), French, Finnish, German, Italian, Indonesian, Dutch, Danish, Norwegian, Portuguese (Brazil and Portugal), Swedish, and Spanish languages.

Directory structure (iOS)

• Dictionaries – contains WritePad dictionaries for all supported languages
• include – contain SDK header files (C API)
• Library– contains WritePad universal static libraries compiled for the device and emulator, including support for 32- and 64-bit.
• WritePadSDK-Sample – sample project in Objective-C that demonstrates usage of the SDK. This project targets iOS SDK 8.0 or later, however, the handwriting recognition library can support older versions of iOS.
• WritePadSDK-Sample-Swift – sample project demonstrating how to use WritePad SDK in iOS application written in Swift. Handwriting recognition manager in Objective-C provides bridge between WritePad C-language API and front end written in Swift.

Directory structure (Android)

• dictionaries – contains WritePad dictionaries for all supported languages
• include – contain SDK header files (C API)
• libs– contains WritePad static native Android libraries compiled for arm64-v8a, armeabi, armeabi-v7a, mips, mips64, x86, and x86_64 CPUs
• sample_astudio – WritePad SDK sample project for Android Studio 1.1+.

Directory structure (Windows)

• Dictionaries – contains WritePad dictionaries for all supported languages
• WinRT_CPPLayer - contains the intermediate C++ library that should be used by managed applications.
• Windows_CPPLayer - contains the intermediate C++ library that should be used by desktop applications.
• lib-windows-metro - contains WritePad static libraries compiled for ARM, x86 and x64 CPU's, for use by metro-style applications.
• lib-windows - contains WritePad static libraries compiled for x86 and x64 CPU's, for use by desktop applications.
• WritePad_CSharpSample - sample C#/XAML metro-style project that demonstrates usage of the SDK.
• WritePad_WPFSample - sample WPF desktop application that demonstrates usage of the SDK.
• WritePad_WinFormsSample – sample Windows Forms application that demonstrates usage of the SDK.

Directory structure (Xamarin)

• Dictionaries – contains WritePad dictionaries for all supported languages.
• include – contain SDK C/C++ header files (not required for Xamarin, but useful as API reference).
• WritePadSDKiOSSample – C# sample project that demonstrates how to use WritePad SDK on iOS platform.
• WritePadSDKAndroidSample – C# sample project that demonstrates how to use WritePad SDK on Android platform.

Compiling the sample project (iOS)

WritePadSDK-Sample and WritePadSDK-Sample-Swift sample projects are included with the SDK targeting both iPad and iPhone devices. 

When creating your own project using the WritePad SDK which does not contain any C or C++ files you may need to specify the additional linker flags in the project settings (Other Linker Flags filed): -cclib -lstdc++

You can use the sample source code in your project when integrating with WritePad SDK. The sample source code is provided “AS-IS” without any warranties. For more information, see the license and warranty disclaimer at the beginning of each source file.

Compiling the sample project (Android)

• Start Android Studio 2.2 or later
• Choose Open an existing Android Studio project and naviage to <sdk_path>/Android/sample_astudio folder
• Choose Build/Make Project menu command
• Run sample app on device or emulator

Compiling the sample project (Windows)

You should first compile the included WinRT_CPPLayer project for the chosen CPU in Release mode. Then you can compile the WritePad_CSharpSample project on the same CPU architecture in Release mode and run it.

To compile the WPF sample or Windows Forms sample, you should first compile the included Windows_CPPLayer project for the chosen CPU in Release mode. Then you can compile the WritePad_WPFSample or WritePad_WinFormsSample project on the same CPU architecture in Release mode and run it.

You need Visual Studio 2015 (any edition) to compile and run the included samples. You can use the sample source code in your project when integrating with WritePad SDK. The sample source code is provided "AS-IS" without any warranties. For more information, see the license and warranty disclaimer at the beginning of each source file.

Compiling the sample project (Xamarin)

• WritePadSDKiOSSample sample project is included with the SDK. This is a universal app, which targets iPad and iPhone devices, however for handwriting recognition demonstration purposes, we recommend to try it on iPad due to the larger screen size.

  1. Locate the WritePadSDKiOSSample.sln file in the WritePadSDKiOSSample folder and open with Xamarin Studio.
  2. Build the project and execute on the device or emulator.
  3. When application starts, write one or more words in the selected language (English is set by default) horizontally on the yellow pad, and then press the Recognize button to convert to text. You can also use the Return gesture (see documentation for description of gestures).

• WritePadSDKAndroidSample sample project for Android OS is also included with the SDK.

  1. Locate the XamarinSDKSample.sln file in the WritePadSDKAndroidSample folder and open with Xamarin Studio.
  2. Build the project and execute on the device or emulator.
  3. When application starts, write one or more words in the selected language (English is set by default) horizontally on the yellow pad, and then press the Recognize button to convert to text. You can also use the Return gesture (see documentation for description of gestures).

Note: the handwriting recognition library is a native library with standard C APIs. You can access any of C function from the library directly from C# very similarly on either platform. For example: 


• on iOS:

  [DllImport("__Internal", EntryPoint = "HWR_GetResultWord")]
  private static extern IntPtr HWR_GetResultWord( IntPtr reco, int nWord, int nAlternative ); 
  
  public static String recoResultWord(int column, int row) { 
      return Marshal.PtrToStringUni(HWR_GetResultWord(recoHandle, column, row)); 
  }

• on Android:

  [DllImport("libWritePadReco.so", EntryPoint = "HWR_GetResultWord")]

  private static extern IntPtr HWR_GetResultWord(IntPtr reco, int nWord, int nAlternative);
  
  public static String recoResultWord(int column, int row) { 
      return Marshal.PtrToStringUni(HWR_GetResultWord(recoHandle, column, row)); 
  }

Please note that a use the SDK sample code, or any portion of it, in an application that is not integrated with the WritePad SDK is prohibited and will constitute violation of the WritePad SDK License Agreement. 

***PhatWare and WritePad are registered trademarks of PhatWare corporation in the US and/or other countries.