Apparatus and method for vectorization of incoming scanned image

131 Pages·2013·5.95 MB·English

United States Patent [19]
[11] Patent Number: 4,817,187
Lien [45] Date of Patent: Mar. 28, 1989
54 ARATUS AND METH D FOR
[ ] yJgIORIZATION 0F ENSOMING FOREIGN PATENT DOCUMENTS
SCANNED IMAGE DATA 2131660 6/1984 United Kingdom .
[75] Inventor: Yih-Liang L. Lien, Chandler, Ariz. primayy Examiner_l_,eo I-I, Boudreau
[73] Assigneez GTX Corporation’ Phoenix, Ariz Attorney, Agent, or Firm-Cahill, Sutton & Thomas
[21] Appl. No.: 16,660 [57] ABSTRACT
[22] F 11 ed t Feb. 19, 19 87 Serial data obtained by scanning an object including a
[51] plurality of connected shapes is encoded into “slices”
consisting of colinear connected black pixels and is
Fi'elh of: Search 5261’ 3522/2252 processed and assembled into “records” that contain
382 261 2’63_ £59133’ compact slice data or corner points of trapezoidal
’ ’ ’ ’ ’ shapes. For each shape, a record is fetched and recog
[56] References Cited nized as to whether it is to be represented by a horizon
U_S_ PATENT DOCUMENTS tal, vertical or diagonal vector, an arc vector, or a ?lled
shape. The vector is entered into a table or merged with
2322x553;" """""""""""" " a vector already in the table, or corresponding “?lled
4:097:847 (5/1978 Forsen et aL 382/22 shape” data is generated and entered in the table. Merg
4,107,648 8/1978 Frank ............. .. . 340/1463 ing is accomplished by determining if the input veetor
4,183,013 l/ 1980 Agrawala et al. .... .. 382/22 has an intersection number equal to that of any vector
4,204,232 5/ 1980 Millmo - - - - - - - - - ~ - - - - ~ -~ 332/56 stored in the table, and merging the input vector with
i’iog'i’gg 1? 3:11? et - 3403/8 the stored vector if their respective end points and ori
4’ 56173 5x985 Abe ‘ital ‘ "" "358/;61 entations are sufficiently close.
4,545,067 10/1985 Juvin et a1. . . . . . . . . . .. 382/21
4,603,431 7/ 1986 Grover et a]. ...................... .. 382/56 45 Claims, 12 Drawing Sheets
SET INTERSECTION
POINTER TO CDN'VERG‘
ENCE 0R DWERGM
RECCRD
VB [5
INCREMENT INTDI
SECTION COUNTER
CUT . em seuenm'e
_ "E eluea cmcLe FILLED Poueou
(F, 2, omune m1 ammo. 16)
1s 1? 1s
oe‘neuLrel mmaun “ ceuemre
ARC vecmn VECTOR em
(no. 1F) (mm 1m 1m
1 t t
EXECUTE ENTITY GENER
ATION 8 DBBFMENTIHON
SUBROUYINE (FIG, 3) - MORE 20
YES VECTOR on NO
FOR HESQINT
“APE
US. Patent Mar. 28, 1989 Sheet 1 of 12 4,817,187
START /
I IE; BRANCHES
MARK RECORD As ‘ PROCESSED
PROCEssED
NO V5
”’ SET INTERSECTION
MULTlPLE POINTER TO CONVERG
NON-HORIZ. ENCE OR DIVERGENCE
RECORDs GENER- RE 0RD
ATED #___
(/6
INCREMENT INTER
SECTION COuNTER PROCESSED
I No {/0
' FETCH RECORDS OF
NEXT BLOB OR TRAP
EzOID (FIG. IE)
I
SHAPE
HORIZONTAL
r7
vECTORIzE FRONT f9. GENERATE HORIZONTAL
8 REAR EDGES VECTOR (FIG. IC)
EXEUTE ENTITY
GENERATION 8 DESEG
MENTATION SUBROUTINE
(FIG. 3)
SELECT ONE SIMPLE - I
PART OF COMPLEX SHAPE
I I3 /4
EXECUTE SHAPE REC- GENERATE GENERATE
FILLED CIRCLE FILLED POLYGON
°GN'T"’{;,%P2B,R°“T'“E DATA (FIG. IH) DATA (FIG. IGI
- I II
I (/6 J, (/7 'I, [la
GENERATE
GENERATE GENERATE
ARC VECTOR DIQEQgIQL VERTICAL vECTOR
(FIG. IF) (FIG IE) (FIG. ID)
I I I
I
EXECUTE ENTITY GENER
ATION 8 DESEGMENTATION
SUBROUTINE (FIG. 3)
20
MORE
VECTOR DATA
FOR PRESENT
SHAPE
.FI[ 5E1
US. Patent 4,817,187
Mar. 28, 1989 Sheet 2 Of 12
EXECUTE END POINT
FROM fZOA
FIEUZAI EXTENSION SUBROUTINE
(FIG I5)
PRESENT
ENTITY CONTAINS
MORE THAN 2
VECTORS
I
OUTPUT VECTOR OR FILLED
II I27
CIRCLE, FILLED INTER
SECTION, BLOB , FILLED
POLYGON OR THIN LINE OUTPUT ARC DATA OUTPUT CIRCLE DATA
I I I L
GENERATE GENERATE I
HORIZONTAL vEcToR DIAGONAL VECTOR
22/ [24/ II [249
READ Y OF TOP AND COMPUTE PROJECTION FIND LONGEST VECTOR
BOTTOM SLICES OF UPPER END OF THE BETWEEN THE FOUR
LONGEST FRONT EDGE MIDPOINTS
I r223 vEcTOR MIDPOINT a
| COMPUTE AVERAGE Y SHAPE THICKNESS II K250
243 COMPUTE THE AVERAGE
I (224 I r DIAGONAL SHAPE
COMPUTE PROJECTION THICKNESS
COMPUTE THICKNESS
OF LOWER END OF
OF HORIZ. VECTOR
LONGEST FRONT EDGE I K25
VECTOR, MIDPOINT 8 ENTER COORDINATES
I {225
SHAPE THICKNESS OF DIAGONAL VECTOR
SEARCH FOR MIN LEFT INTO INPUT BUFFER
EDGE X AND MAX RIGHT I r245
EDGE X
COMPUTE PROJECTION
I (226‘ OF UPPER END OF LCNG II
EST REAR EDGE VECTOR ( RETURN I
ENTER END POINTS AND 8| MIDPOINT
THICKNESS OF HORIZ.
VECTOR INTO INPUT
I /247
BUFFER
COMPUTE PROJECTION
I
OF LOWER END OF
(E LONGEST REAR EDGE
VECTOR 8n MIDPOINT
Frizz/ll: I
US. Patent Mar. 28, 1989 Sheet 3 of 12 4,817,187
200
FETCH RECORDS
OF NEXT BLOB
OR TRAPEZOID
I
' 20/
_ ‘ NQAM YES
RECORD T l
READ TRAPEZOID READ SLICE DATA
DATA FROM RECORD FROM RECORD
T
207
END
YES
OF
RECORD
V " (205
MARK RECORD TO
INDICATE IT HAS BEN
PROCESSED
EZOID MUCH DIFFER MUCH DIFFERENT
ENT THAN
THAN PRESENT
PRESENT
SLI CE
NO MORE
RECORDS
2/0
NEXT
RECORD A
BLOB RECORD
2”; T 2/2)
READ THE FIRST READ THE FIRST
TRAPEZOID DATA SLICE DATA FROM
FROM RECORD _ RECORD
T T
COMPUTE RATIO OF /2/5
AVERAGE SLICE LENGTH
TO HEIGTH OF PRESENT
FIEQZB SHAPE
US. Patent Mar. 28, 1989 4,817,187
Sheet 4 0f 12
GENERATE GENERATE FILLED
VERTICAL VECTOR POLYGON DATA
[27/
I, 233/
READ UPPER END READ COORDINATES
POINTS OF FRONT8 OF VERTICES OF FRONT
REAR EDGES OF 8 REAR EDGES 8 FORM
VERTICAL SHAPE 8 FILLED POLYGON RECORD
COMPUTE MIDPOINT
I
I 233 272
NO. OF
READ LOWER END VERTIC ES
POINTS OF FRONT 8 GREATER
REAR EDGES OF THAN 7
VERTICAL SHAPE 8
COMPUTE MIDPOINT YES (273
I 235 CALL "CONTRACT" TO
COMPUTE WIDTH DELETE POINTS, IF
OF VERTICAL SHAPE POSSIBLE (FIG. I4A)
I 236 274
ENTER MIDPOINTS 8
WIDTH OF VERTICAL
VECTOR INTO INPUT
BUFFER
I 275
I
SELECT 7 VERTICES
FROM FRONT AND
REAR EDGES
1 f276
ENTER cooRDINATEs
GE NERATE 0F vERTIcEs INTO
ARC VECTORS INPUT BUFFER
FIFE” @
‘ I, 26/
FIND LOWEST a HIGH- )
EsT Y VALUES IN
THE INPUT DATA
GENERATE FILLED
I 263 ' CIRCLE DATA
COMPUTE MIDPOINTS [28/
BETWEEN CORRESP READ COORDINATES
ONDING mom a REAR OF 3 POINTS FROM
EDGE END POINT FRONT 8 REAR EDGES
COORDINATES
I
/282
y 2615 COM PUTE CENTER
8 RADIUS
vEcToRIzE MIDPOINTS
I, 266 II
COM PUTE SHAPE / ENTER INTO INPUT
THICKNESS BUFFER
I 267 II
ENTER COORDINATES a J I RETURN I
THICKNESS OF ARC
VECTOR INTO INPUT
BUFFER
I
@ Fl-Em?:
US. Patent Mar. 28, 1989 Sheet 5 0f 12 4,817,187
SHAPE RECOGNITION
FIEGB ( SUBROUTINE >//2A
i (36
FIND LoNGEsT VECTOR
0F FRONT a REAR EDGEs
‘ r37 ‘ v (44
couNT No. OF VECTORS COMPUTE ANGLE
OF FRONT a REAR BETWEEN LoNGEsT
EDGEs OF LENGTH VECTOR OF FRONT
SIMILAR TO LoNGEsT EDGE a LoNGEsT
VECTOR OF THAT EDGE VECTOR OF REAR EDGE
BOTH HAVE MULT ARE
IPLE VECTORS OF LONGEST
SIMILAR YES VECTORS OF FRONT
LENGTH 8 REAR EDGES
PARALLEL
IS
GENERATE CODE OF
SHAPE
coNvEx FILLED POLYGON
GENERATE 47 ‘
ARE x
ARC CODE 42 COORDINATES
- GENERATE<
INTERSECTION EQUAL
BLOB coDE
# (43 (48 ‘ <49
GENERATE GENERATE GENERATE
50 FILLED CIRCLE VERTICAL DIAGONAL
CODE VECTOR CODE vEcToR CODE
( RETURN y " ‘ _ _ + ‘
/67 /68
US. Patent Mar. 28, 1989 Sheet 6 0112 4,817,187
ENTITY GEN. a ,9A
DESEGMENTATION
IS
INPUT
VECTOR AN
ARC VECTOR
$5714 59) ‘I 60)
EXECUTE FILLED EXECUTE LINE EXECUTE ARC
POLYGON DESEG- DESEGMENTATION DESEGMENTATION
MENTATION SUB- SUBROUTINE (FIG.4) SUBROUTINE( FIG.5)
ROUTINE (FIG. I4) + J
l T 6,
57B
D\D DID
DESEG DESEG
MENTATI ON MENTATION
OCCUR OCCUR
ENTER FILLED (57D ' 63 64? "
CIRCLE OR COMBINE FILLED ENTER INPUT UPDATEVECTOR WITH
FILLED POLYGON POLYGON WITH STORED VECTOR INTO SAMEINTERSECTION
INTo FILLED SHAPE FILLED POLYGON IN VECTOR TABLE NUMBER BY ADDING
TABLE FILLED SHAPE TABLE v INPuT VECTOR To IT
5705 T + f I
l5/C
FIE/3H
US. Patent 4,817,187
Mar. 28, 1989 Sheet 7 0f 12
FIE/:74 ( DESEGMLEINNTEA TION >594
v 595
I RESET COMBINE FLAG
YES
BEGIN AT OPEN
POINT 8 END AT
DIVERGENCE
I 69)
COMPUTE LENGTH
OF INPUT VECTOR
72)
COMPUTE LENGTH
OF INPUT VECTOR
I 73
NO
HAVE SAME INTER
SECTION NO. AS INPUT
VECTOR
76»
IS
VECTOR IN EXECUTE ARC
TABLE AN ARC DESEGMENTATION
VECTOR SUBROUTINEI FIG.5I
FIND 2 'CLOSEST END
POINTS OF THAT STORED
VECTOR 8 INPUT VECTOR
I
A COMPUT. E OFFSET BE- / 79
TWEEN CLOSEST END
POINTS 8 STRAIGHT
6,2 LINE BEWEEN OUTER
/ END POINTS
ADD INPUT VECTOR ‘90
VEECCIBOFIIIIO EH“
v v CTOR IN VECTORTABLE I
TABLE 8 SET BE COMBINED WITH
COMBINE FLAG INPUT VECTO
I RETURN I
US. Patent Mar. 28, 1989 Sheet 8 of 12 4,817,187
ARC
DESEGMENTATION 60A
608
| REsET COMBINE FLAG
I SQ/
FIND 2 CLOSEST END
POINTS OF INPUT ARC
VECTOR a VECTOR IN
vEcToR TABLE HAVING
PRESENT INTERSECTION
NUMBER
COMPUTE THE LENGTH
RATIO OF INPUT ARC
VECTOR GI VECTOR IN
VECTOR TABLE
ARE
LENGTHS
SIMILAR
COMPUTE INTERSECTION
ANGLE OF INPUT ARC
VECTOR 8 VECTOR IN
VECTOR TABLE
DETERMINE /9&9
CIRCULARITY
DETERMINE
CONVEXITY
DO
INPUT VECTOR
BIVECTOR IN TABLE
FORM CONVEX
SHAPE
/0/
I COMBINE INPUT VECTOR
RETURN WITH VECTOR IN TABLE
a SET COMBINE FLAG
I II
F1555
US. Patent Mar. 28, 1989 4,817,187
Sheet 9 0f 12
PRESENT
FILLED POLYGON
CLOSE TO ONE STORED
YES (292
FIND LOWEST POINT
OF UPPER POLYGON
2.93
(30/
HORIZONTAL
EDGE AT THIS ‘ SET NO MERGE FLAG
YES (294
FIND HIGHEST POINT
OF LOWER POLYGON
2.95
v (300
HORIZONTAL ENTER MERGED FILLED
EDGE AT THIS POLYGON VE RTICES
INTO INPUT BUFFER
I
GENERATE MERGED I RETURN >
FILLED POLYON
RECORD INCLUDING
ALL VERTICES IN
BOTH GIVEN POLYGONS
' (2.97
ELIMINATE EXTRA
PONTS AT THE MERGE
JUNCTION IF STRAIGHT
LINE IS FORMED AT
JUNCTION EDGE
I 9298
CALL "CONTRACT"
ROUTINE TO REMOVE
MORE UNNECESSARY
POINTS OF THE COMB
INED POLYGON (FIG. I4A)