Patent US5146511A successfully refreshed from Google Patents.
US5146511A
Expired / Lapsed
US
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Image processing method and apparatus therefor
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1991-04-30
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Granted: 1992-09-08
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Expires: 2011-04-30
Abstract
Abstract The image processing device finds core linear segments of a linework image by thinning processing; provides a mask area for each end point of the linear segments; integrates the mask areas overlapping with each other into a sum area; with respect to each sum area, finds effective linear segments which have only one end point within each sum area; and judges a feature point in each sum area according to the number of the effective linear segments. Therefore, the device is advantageous in that the feature points are classified more accurately because the linear segments irrelevant to judging the feature points (such as those produced due to distortion and line missing) can be eliminated in the judgment. It is also advantageous in that the data amount to be handled is small and classifying is completed at a high speed since the feature points are classified after vectorization of raster data.
Inventors
- 👤 Akihiko Shirasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:40
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/40; G06V10/44
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
159 words
An image processing apparatus for finding and classifying feature points existing in a linework image, said feature points being points having a plurality of branches and end points of said linework image, comprising: (a) linear segment detecting means for detecting linear segments representing core parts of said linework image by thinning processing, to thereby producing vector data representing said linear segments; (b) mask area establishment means for establishing mask areas for respective end points of said linear segments identified by said vector data; (c) sum area production means for producing a sum area of said mask areas overlapping with each other; (d) set finding means for, with respect to each of said sum areas, finding a set of effective linear segments which have only one end point within each of said sum areas; and (e) feature point classifying means for classifying said feature points in each of said sum areas according to the number of elements of said set.
Claim 2
Dependent Claim
159 words
An image processing apparatus for finding and classifying feature points existing in a linework image, said feature points being points having a plurality of branches and end points of said linework image, comprising: (a) linear segment detecting means for detecting linear segments representing core parts of said linework image by thinning processing, to thereby producing vector data representing said linear segments; (b) mask area establishment means for establishing mask areas for respective end points of said linear segments identified by said vector data; (c) sum area production means for producing a sum area of said mask areas overlapping with each other; (d) set finding means for, with respect to each of said sum areas, finding a set of effective linear segments which have only one end point within each of said sum areas; and (e) feature point classifying means for classifying said feature points in each of said sum areas according to the number of elements of said set.
Claim 3
Dependent Claim
78 words
An image processing apparatus in accordance with claim 1, wherein said feature point classifying means judges said feature points as end points if the number of effective linear segments is one; judges said feature points as connection points if the number of effective linear segments is two; and judges said feature points as N-branch points having N pieces of branches, where N is an integer at least three, if the number of linear segments is at least three.
Claim 4
Dependent Claim
28 words
An image processing apparatus in accordance with claim 1, wherein said mask area establishment means establishes area selected from a group consisted of square, rectangle, circle, and oval.
Claim 5
Dependent Claim
47 words
An image processing apparatus in accordance with claim 3, wherein said mask area establishment means establishes said mask areas whose width in a first direction parallel to a longitudinal direction of said linear segment is longer than a width in second direction perpendicular to said first direction.
Claim 6
Dependent Claim
48 words
An image processing apparatus in accordance with claim 1, wherein said mask area establishment means comprises: (b1) linear segment width measuring means for measuring a width of said linework image; and (b2) area size adjusting means for adjusting size of said mask areas in proportion to said width.
Claim 7
Dependent Claim
53 words
An image processing apparatus in accordance with claim 1, wherein said mask area establishment means further comprises; mask area information storage means for storing information of each of said mask areas, said information including at least coordinates of location of said mask areas, while allotting a unique identity number to every mask area.
Claim 8
Dependent Claim
72 words
An image processing apparatus in accordance with claim 1, wherein said sum area production means comprises: (c1) identity number assigning means for assigning identity number to each mask area, while assigned an identical identity number to those mask areas which overlap at least partly with each other; and (c2) identical sum area judgement means for judging mask areas allotted with an identical identity number to be included in an identical sum area.
Claim 9
Dependent Claim
47 words
An image processing apparatus in accordance with claim 1, wherein said feature point classifying means operates after production of each said sum area and after finding the number of elements in said set of effective linear segments having only one end point within each said sum area.
Claim 10
Dependent Claim
135 words
An image processing method for finding and classifying feature points existing in a linework image, said feature points being points having a plurality of branches and end points of said linework image, comprising: (a) detecting linear segments representing core parts of said linework image by thinning processing, to thereby producing vector data representing said linear segments; (b) establishing mask areas for respective end points of said linear segments identified by said vector data; (c) producing a sum area of said mask areas overlapping with each other; (d) with respect to each of said sum areas, finding a set of effective linear segments which have only one end point within each of said sum areas; and (e) classifying said feature points in each of said sum areas according to the number of elements of said set.
Claim 11
Dependent Claim
135 words
An image processing method for finding and classifying feature points existing in a linework image, said feature points being points having a plurality of branches and end points of said linework image, comprising: (a) detecting linear segments representing core parts of said linework image by thinning processing, to thereby producing vector data representing said linear segments; (b) establishing mask areas for respective end points of said linear segments identified by said vector data; (c) producing a sum area of said mask areas overlapping with each other; (d) with respect to each of said sum areas, finding a set of effective linear segments which have only one end point within each of said sum areas; and (e) classifying said feature points in each of said sum areas according to the number of elements of said set.
Claim 12
Dependent Claim
83 words
An image processing method in accordance with claim 9, wherein said step (e) comprises the steps of: (e1) judging said feature points as end points if the number of effective linear segments is one; (e2) judging said feature points as connection points if the number of effective linear segments is two; and (e3) judging said feature points as N-branch points having N pieces of branches, where N is an integer at least three, if the number of linear segments is at least three.
Claim 13
Dependent Claim
26 words
An image processing method in accordance with claim 9, wherein said each mask area is selected from the group consisted of square, rectangle, circle, and oval.
Claim 14
Dependent Claim
37 words
An image processing method in accordance with claim 11, whose width in a first direction parallel to a longitudinal direction of said linear segment is longer than a width in second direction perpendicular to said first direction.
Claim 15
Dependent Claim
38 words
An image processing method in accordance with claim 9, wherein said step (b) comprises the steps of: (b1) measuring a width of said linework image; and (b2) adjusting size of said mask areas in proportion to said width.
Claim 16
Dependent Claim
39 words
An image processing method in accordance with claim 9, where information of each of said mask areas is stored, said information including coordinates of location of said mask areas, while allotting a unique identity number to every mask area.
Claim 17
Dependent Claim
62 words
An image processing method in accordance with claim 9, wherein said step (c) comprises the steps of: (c1) assigning identity number to each mask area, while assigning an identical identity number to those mask areas which overlap at least partly with each other; and (c2) judging mask areas allotted with an identical identity number to be included in an identical sum area.
Claim 18
Dependent Claim
54 words
An image processing method in accordance with claim 9, wherein said step of classifying said feature points in said sum areas is performed after production of each said sum area and after finding the number of elements in said set of effective linear segments having only one end point within each said sum area.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |