Method for storing and comparing computer generated lines

• US 20060071906A1
• Filed: 10/05/2004
• Published: 04/06/2006
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: Jclads Corporation
• Original Assignee: Jclads Corporation
• Inventors: Pham, Nghia Van
• Granted Patent: US 7,663,614 B2
• Time in Patent Office: Days
• US Class Current: 345/163
• CPC Class Codes: G06F 2218/12 Classification; Matching
• CPC Class Codes: G06F 40/194 Calculation of difference between files
• CPC Class Codes: G06V 30/1423 the instrument generating sequences of position coordinates corresponding to handwriting preprocessing or recognising digital ink G06V30/32
• CPC Class Codes: G06V 40/394 Matching; Classification

Abstract

A method is provided for creating a quadrant array by using two consecutive points in an array of x, y coordinate values generated by movements of a computer mouse or a digitizer tablet. The quadrant array is then saved in computer storage for later verification with a sample quadrant array by using a comparison function.

Claims

1. A method for creating an array of quadrants using a computer, the computer comprising a processor, a memory, and either a computer mouse or a digitizer tablet, the method comprising:

capturing a series of x, y coordinate values generated by either a computer mouse or a digitizer tablet and using consecutive points to create an quadrant array that can be stored in computer storage according to the following pseudo code;

for i = 0 to N −

1 

 

xVal = x[ i + 1 ] −

x[ i ] 

 

yVal = y[ i + 1 ] −

y[ i ] 

 

QARRAY[ i ] = QUAD_1 

 

if xVal >

0 &

&

yVal >

0 

 

 

 

then QARRAY[ i ] = QUAD_1 

 

if xVal <

0 &

&

yVal >

0 

 

 

 

then QARRAY[ i ] = QUAD_2 

 

if xVal <

0 &

&

yVal <

0 

 

 

 

then QARRAY[ i ] = QUAD_3 

 

if xVal >

0 &

&

yVal <

0 

 

 

 

then QARRAY[ i ] = QUAD_4

where

x[i] and y[i] over the range i=0 to i=N−

1 is the discrete representation of a line,

QARRAY[i] over the range i=0 to i=N−

2 is the quadrant array,

QUAD_—

1, QUAD_—

2, QUAD_—

3, and QUAD_—

4 are integers,

xVal and yVal are integers, and

N is the number of points.

2. A method for comparing two quadrant arrays comprising:

calculating the difference between the quadrant array sizes according to the following relationships;

diff=LC2*errorThreshold
LC1>

=LC2−

diff &

&

LC1<

=LC2+diff

where

errorthreshold is a decimal number from 0 to 1 inclusive,

LC1 represents the smallest quadrant array size,

LC2 represents the largest quadrant array size, and diff is the error difference calculated by taking LC2 multiply that by errorThreshold;

3. A method for comparing two quadrant arrays comprising:

calculating the number of matched quadrant elements of two quadrant arrays according to the following pseudo code;

PQM = 0QM = 0for k = 0 to k <

30 

 

for i = 0 to i <

LC1 −

k 

 

 

 

if L1 [ i ] == L2[ i + k ] 

 

 

 

 

 

increment PQM 

 

 

 

if i <

LC1 −

k 

 

 

 

 

 

break 

 

if PQM >

QM 

 

 

 

then QM = PQM 

 

QM = 0 

 

If k == 30 

 

 

 

break

where

L1[i] and L2[i] are quadrant arrays,

PQM is the previous number of quadrant matches,

QM is the number of quadrant matches,

LC1 is the smallest number of points,

k ranges from 0 to 30 inclusive, and

i ranges from 0 to i<

LC1−

k.