InkML

Please refer to the errata for this document, which may include some normative corrections. This document describes the syntax and semantics for the Ink Markup Language. The Ink Markup Language serves as the data format for representing ink entered with an electronic pen or stylus. The markup allows for the input and processing of handwriting, gestures, sketches, music and other notational languages in applications. It provides a common format for the exchange of ink data between components such as handwriting and gesture recognizers, signature verifiers, and other ink-aware modules. It may be used in the W3C Multimodal Interaction Framework as proposed by the W3C Multimodal Interaction Activity . This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at Comments are welcome on [email protected] (archive ). See W3C mailing list and archive usage guidelines . This specification describes markup for representing ink entered with an electronic pen or stylus and forms part of the proposals for the W3C Multimodal Interaction Framework . This document was produced by a group operating under the 5 February 2004 W3C Patent Policy . W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. D The InkML Media Type D.1 Registration of MIME media type application/inkml+xml As more electronic devices with pen interfaces have and continue to become available for entering and manipulating information, applications need to be more effective at using this method of input. Handwriting is a powerful and versatile input modality that is very familiar for most users since everyone learns to write in school. Hence, users will tend to use this as a mode of input and control when available. A pen-based interface is enabled by a device that allows movements of the pen to be captured as digital ink. A number of methods may be used for ink capture, including those based on radio frequency, optical tracking, physical pressure, or other technologies. Digital ink can be passed on to recognition software that will convert the pen input into appropriate computer actions. Alternatively, the handwritten input can be organized into ink documents, notes or messages that can be stored for later retrieval or exchanged through telecommunications means. Such ink documents are appealing because they capture information as the user composed it, including text in any mix of languages and drawings such as equations and graphs. Hardware and software vendors have typically stored and represented digital ink using proprietary or restrictive formats. The lack of a public and comprehensive digital ink format has severely limited the capture, transmission, processing, and presentation of digital ink across heterogeneous devices developed by multiple vendors. In response to this need, the Ink Markup Language (InkML) provides a simple and platform-neutral data format to promote the interchange of digital ink between software applications. InkML supports a complete and accurate representation of digital ink. In addition to the pen position over time, InkML allows recording of information about device characteristics and detailed dynamic behavior to support applications such as handwriting recognition and authentication. For example, there is support to record additional information such as pen tilt and pen tip force (often referred to as "pressure") and information about the recording device such as accuracy and dynamic distortion. InkML also provides features to support rendering of digital ink captured optically to approximate the original appearance. For example, stroke width and color information can be recorded. With the establishment of a non-prop