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# Curve Generator using Overlapped Stroke Data

IP.com Disclosure Number: IPCOM000115403D
Original Publication Date: 1995-Apr-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 54K

IBM

## Related People

Kuriyama, S: AUTHOR [+2]

## Abstract

Disclosed is a system for input of the curve by overlapped strokes. The system generates a list of lines from the stroke data input by mouse or tablet. The curve fitting algorithm finds out the curve from the list of lines.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 84% of the total text.

Curve Generator using Overlapped Stroke Data

Disclosed is a system for input of the curve by overlapped
strokes.  The system generates a list of lines from the stroke data
input by mouse or tablet.  The curve fitting algorithm finds out the
curve from the list of lines.

The designer often uses overlapped strokes to define a curve,
therefore the system is suitable for such an artistic design
environment.

The system first defines a 2D grid over 2D input device, and
defines a distribution function over the lines that connect the
points on the grid.  The lines are called grid segments.

The distribution function D(t) has to satisfy the following
conditions:
<Max{D(t)} = D(0)>
lvabove <D(t) = D(-t)> lvabove <lim midsub
<t .rar  .pm  .inf> D(t) = 0>

The example of such functions are Gaussian base:
D(t) colon = w bullet e sup < left (<-t sup 2> over R right)
>, t is in range [-R,R]

Each input stroke, the system gets the intersection with grid
segments, defines the distribution function over the point, and
accumulates the function.

After all the strokes are input, the system calculates the
distribution of each grid segments, finds the maximum value point as
the candidate point of line, and sorts the list of points so that the
lines connecting the points becomes natural.  Example of the criteria
is as follows:
P sub i , i=1 .ellipsis N : points
T(P sub i) = <(P sub <i+1> - P sub i...