Browse Prior Art Database

Optical Character Recognition in a Pen-Based Computer

IP.com Disclosure Number: IPCOM000106489D
Original Publication Date: 1993-Nov-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 78K

Publishing Venue

IBM

Related People

Chevion, DS: AUTHOR

Abstract

Disclosed is optical character recognition (OCR) within a pen-based computer through modifications added to the on-line classifier provided to perform the recognition of characters entered by writing on the screen of the computer.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Optical Character Recognition in a Pen-Based Computer

      Disclosed is optical character recognition (OCR) within a
pen-based computer through modifications added to the on-line
classifier provided to perform the recognition of characters entered
by writing on the screen of the computer.

      A pen-based computer is a tablet-like device including a screen
on which characters are individually entered by handwriting, using a
special stylus, or "pen."  The screen also operates as a display
device.

      As shown in the block diagram, a pen-based computer 8 includes
a tablet input function 10, which digitizes the movements of pen 12
on the surface of a screen.  A method is provided for sensing when
pen 12 touches the surface of the screen and when it is removed from
the screen.  As the pen is moved along the screen, its trajectory is
digitized and a sequence of coordinates are grouped in a record named
a "stroke."

      Strokes are fed into an on-line classifier 14, to be matched
against a stored tablet prototype library 16, which is a collection
of handwritten characters providing the entire set of symbols
recognized by the system as allowable inputs from tablet input
function 10.  Each character in prototype library 16 is an ordered
set of strokes.  When all of the strokes recognized as making up a
character have been completed, classifier 14 sends the character to
display function 18.

      To perform optical character recognition, an input document is
scanned by a FAX unit 20, providing data to pen-based computer 8
through a modem 22.  This data is stored as a bitmap 24, including
the coordinates of all the pixels forming the image.

      Bit/stroke module 26 is program module in which image
processing techniques, known as raster to vector conversion, are used
to convert the pixel image of each individual line from bitmap 24 to
its vector r...