Browse Prior Art Database

Method for Varying the Input Reporting Rate of Pointing Device Movement

IP.com Disclosure Number: IPCOM000115202D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 89K

Publishing Venue

IBM

Related People

Tannenbaum, AR: AUTHOR [+3]

Abstract

Disclosed is a method for improving the user interface of a computer accepting input from a high-performance pointing device, such as a digitizing sensor used with a stylus. Means are provided for applications to reduce the rate at which points indicating the X/Y position of the stylus are sampled, with the point rate being specified, not at an absolute level, but rather at an upper limit not to be exceeded.

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

Method for Varying the Input Reporting Rate of Pointing Device Movement

      Disclosed is a method for improving the user interface of a
computer accepting input from a high-performance pointing device,
such as a digitizing sensor used with a stylus.  Means are provided
for applications to reduce the rate at which points indicating the
X/Y position of the stylus are sampled, with the point rate being
specified, not at an absolute level, but rather at an upper limit not
to be exceeded.

      A typical pen computer employs a digitizing sensor to sense and
report movement of the stylus, as the user provides input on an
interface simulating pen and paper, with freehand drawings,
handprinted characters, or cursive writing.  To faithfully reproduce
the path of the stylus, the sensor must accurately report X/Y
positions, generating a high number of coordinates per second.
However, no  appreciable increase in handwriting or gesture
recognition accuracy is achieved by increasing the sampling rate
above 100 points per second.  In fact, such an increase in the
sampling rate results in a small performance penalty because the
recognition engine must filter extraneous points before performing
recognition.  Benefits are derived from much higher point rates only
when the user is drawing freehand.  A high point rate permits the
user to draw at relatively high speeds, with even sharp curves
providing a smooth appearance.  Therefore, by default, Pen for OS/2*
configures pen devices to report 100 points per second.  The point
rate is configurable within a range of 40 to 200 points per second.

      Many conventional drawing applications, not being designed to
handle a high point rate, take advantage of a feature of the
operating system which allows coordinates to be coalesced or
discarded if an application is unable to handle points as fast as
they are generated by the hardware.  Since using  this feature
degrades the accuracy of drawing applications, Pen for OS/2 permits a
user to override this feature, so that the application receives all
the points generated.  However, a drawing application for a pen
computer typically provides an inking function to draw a line on the
screen following the motion of the stylus.  When the feature allowing
points...