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 Title: |
US5506947:
Curve and surface smoothing without shrinkage
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Taubin, Gabriel; Hartsdale, NY
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| Assignee: |
International Business Machines Corporation, Armonk, NY
other patents from INTERNATIONAL BUSINESS MACHINES CORPORATION (280070) (approx. 44,393)
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| Published / Filed: |
1996-04-09
/ 1994-09-22
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| Application Number: |
US1994000310820
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| IPC Code: |
Advanced:
G06T 11/20;
G06T 15/00;
G06T 17/20;
G06T 17/30;
Core:
more...
IPC-7:
G06T 5/00;
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| ECLA Code: |
G06T17/20;
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| U.S. Class: |
Current:
345/441;
345/420;
345/423;
345/428;
345/606;
345/611;
345/643;
Original:
395/133;
395/120;
395/123;
395/141;
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| Field of Search: |
395/133,119,120,123,125,127-132,139,141-143
382/254,264,266-269
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| Priority Number: |
| 1994-09-22 |
US1994000310820 |
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| Abstract: |
The present invention smooths piece-wise linear shapes by defining neighborhoods of vertices around vertices of the shape. One or more vectors is defined between the vertex and each of its neighbors. Vector sums are alternately multiplied by one of two scale factors. The scale factors are opposite in sign with the negative scale factor of larger magnitude. The vertices of the shape are displaced by the multiplied vector sums to attain new positions. The process is repeated with the vertices moving back and forth approximately through their final position until the shape is smoothed without shrinkage.
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| Attorney, Agent or Firm: |
Percello, Louis J. ;
Drumheller, Ronald L. ;
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| Primary / Asst. Examiners: |
Jankus, Almis R.;
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| Maintenance Status: |
E1 Expired Check current status
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| INPADOC Legal Status: |
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Family Legal Status Report
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| Designated Country: |
DE FR GB
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| Family: |
Show 3 known family members
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First Claim:
Show all 18 claims |
I claim:
1. A computer implemented method for smoothing a piece-wise linear shape represented on a computer as a set of vertices, comprising the computer implemented steps of:
- a. determining a neighborhood associated with each vertex, each neighborhood comprising a subset of zero or more neighbor vertices from the set of vertices such that the vertex is not included in its neighborhood;
- b. describing a first and a second scale factor of opposite signs, the negative scale factor being of greater magnitude than the positive scale factor;
- c. determining a first vector displacement for each vertex, the first vector displacement being the first scale factor times a first vector average, the first vector average being the average of all of the zero or more neighbor vectors, each neighbor vector being a vector from the vertex to each of its neighbor vertices, all the vertices being at a respective current position;
- d. determining a first position of each vertex, the first position being the position of the vertices moved by their first vector displacement from their current position, respectively;
- e. determining a second vector displacement for each vertex, the second vector displacement being the second scale factor times a second vector average, the second vector average being of the average of all of zero or more second neighbor vectors, each second neighbor vector being a vector from the vertex to each of the neighbor vertices, all vertices being at their respective first position, respectively;
- f. determining a second position of each vertex, the second position being the position of the vertices moved by their respective second vector displacement from their first position, respectively;
- g. establishing the current position of each vertex as its respective second position; and
- h. if the shape defined by the vertices in their second position does not meet a smoothness criteria, repeating steps c through h until the smoothness criteria is met.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 36 U.S. patent(s) that reference this one
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| Foreign References: |
None
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| Other Abstract Info: |
DERABS G96-161856
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| Other References: |
Paul Ning et al, An Evaluation of Implicit Surface Tilers, IEEE Computer Graphics & Applications, Nov. 1993, pp. 33-41.
(9 pages)
Cited by 2 patents
[ISI abstract]
Richard O. Duda et al, Pattern Classification and Scene Analysis, Wiley-Interscience Publication, John Wiley & Sons, pp. 291-297.
Mark Halstead et al, Efficient, Fair Interpolation using Catmull-Clark Surfaces, Computer Graphics Proceedings, Annual Conference Series, 1993, pp. 35-44.
B. K. P. Horn et al, Filtering Closed Curves, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. PAMI-8, No. 5, Sep. 1986, pp. 665-668.
(4 pages)
M. Lounsbery et al, Parametric Surface Interpolation, IEEE Computer Graphics & Applications, Sep. 1992, pp. 45-52.
(8 pages)
[ISI abstract]
J. Oliensis, Local Reproducible Smoothing without Shrinkage, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 15, No. 3, Mar. 1993, pp. 307-312.
(6 pages)
Cited by 2 patents
[ISI abstract]
D. Watson, Smoothing ISO-Surfaces Composed of Polygons, , IBM Technical Disclosure Bulletin, vol. 34, No. 4B, Sep. 1991, p. 474.
James D. Foley et al, Representing Curves and Surfaces, Computer Graphics Principles and Practice, Second Edition, pp. 471-477, pp. 612-613, pp. 1034-1039, pp. 1083-1113.
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