Digital ink coding method, digital ink decoding method, digital ink data structure, and method of generating file including digital ink

A digital ink decoding method for reproducing a path of a pointing device from a binary stream including coded digital ink, the digital ink decoding method comprising:

• a position data decoding step of decoding N pieces of position data acquired in connection with a motion of the pointing device during a period determined by a state of the pointing device from a first region in the binary stream;
• a width data decoding step of decoding M pieces of width data defining widths at positions indicated by N pieces of position data from a second region different from the first region in the binary stream, where M is an integer equal to or greater than 1 and equal to or smaller than N;
• and
• a width interpolation step of interpolating a width at a position of each of N-M positions, when M is smaller than N, using any of M pieces of width data.

A computer-readable non-transitory medium including a digital ink data structure, wherein

• the digital ink data structure includes, in mutually different regions, a first binary data obtained by coding N pieces of position data acquired in connection with a motion of a pointing device during a period determined by a state of the pointing device and a second binary data obtained by coding M pieces of width data defining widths at positions indicated by N pieces of position data, where M is an integer equal to or greater than 1 and equal to or smaller than N, and
• the digital ink data structure is configured to enable decoding of digital ink having the digital ink data structure, wherein the decoding includes:
• restoring N pieces of position data from the first binary data;
• restoring M pieces of width data from the second binary data;
• and
• associating M pieces of width data with N pieces of position data.

A method of generating a file including coded digital ink, the method comprising:

• a first coding step of acquiring a binary stream by using a first coding method to code N pieces of position data acquired in connection with a motion of a pointing device during a period determined by a state of the pointing device;
• a first metadata binary generation step of generating a first Extensible Markup Language (XML) file by acquiring metadata for the binary stream and using a second coding method to code first XML data including the metadata;
• a second metadata binary generation step of generating a second XML file by generating second XML data indicating a relationship between a target identification information indicative of the binary stream and the metadata and using the second coding method to code the second XML data;
• and
• a package generation step of archiving the binary stream, the first XML file, and the second XML file in one package file.