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 Title: |
US5974168:
Acquiring bump maps from curved objects
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Rushmeier, Holly Edith; Mt. Kisco, NY
Taubin, Gabriel; Hartsdale, NY
Gueziec, Andre Pierre; Mamaroneck, 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: |
1999-10-26
/ 1998-04-16
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| Application Number: |
US1998000061564
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| IPC Code: |
Advanced:
G06T 7/40;
Core:
more...
IPC-7:
G06K 9/00;
G06K 9/46;
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| ECLA Code: |
G06T7/40;
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| U.S. Class: |
Current:
382/141;
382/154;
382/190;
Original:
382/141;
382/154;
382/190;
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| Field of Search: |
382/141,154,100,103,104,108,106,151,153,169,174,190,191,195,276
364/513,413-415,560-563
358/102,403
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| Priority Number: |
| 1998-04-16 |
US1998000061564 |
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| Abstract: |
A method and system for obtaining and processing acquired images of an object to extract a small scale geometry (a bump map) of the object that is independent of object curvature. The method includes steps of (a) operating N (where N>3) light sources and an image input device placed at a distance from the object such that different regions of the object are illuminated by each of the multiple light sources; (b) obtaining multiple images of the object, one for each of the light sources with the other light sources turned off; (c) processing the images to derive three images, each corresponding to a component of surface normals of the object relative to directions to three of the light sources; (d) removing an effect of large scale surface shape from the derived images of the surface normals by computing low spatial frequency images from the derived images; (e) for a section or sections of the images for which the small scale geometry is to be acquired, determining transformations from the surface normals represented by the low spatial frequency images to the normals of a planar surface; (f) applying the transformations to the derived surface normal images to obtain the normals of the small scale surface variations applied to a flat plane; (g) adjusting a spacing of the values for the normals to account for foreshortening due to curvature by expanding the distances using directional derivatives computed from the surface normals at each point in the image; and (h) obtaining regularly spaced images of new surface normals by sampling the spatially adjusted images onto a new, regularly spaced image.
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| Attorney, Agent or Firm: |
Sbrollini, Esq., Jay P.Perman & Green, LLP ;
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| Primary / Asst. Examiners: |
Couso, Jose L.; Dang, Duy M.
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| Maintenance Status: |
E2 Expired Check current status
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| INPADOC Legal Status: |
Show legal status actions
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| Family: |
None
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First Claim:
Show all 17 claims |
What is claimed is:
1. A method for acquiring an image of small scale surface features of an object, comprising the steps of:
- successively illuminating the object with one of N light sources and, for each light source, obtaining a grey scale image of the object that is registered with the other grey scale images;
- processing the grey scale images such that for each corresponding pixel only N-X pixels are retained;
- forming N-X processed images having, for each image pixel, a computed surface normal;
- spatially filtering the N-X processed images to form N-X spatially filtered images of the processed images;
- transforming, using the N-X spatially filtered images, the surface normals of the processed images to form a set of N-X planar surface images; and
- generating from the set of N-X planar surface images a set of N-X final images having surface normals that represent the small scale surface features of the object that are substantially independent of object curvature.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 14 U.S. patent(s) that reference this one
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| Foreign References: |
None
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| Other Abstract Info: |
DERABS G2000-021887
DERABS G2000-021887
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| Other References: |
"Fitting Smooth Surfaces to Dense Polygon Meshes", V. Krishnamurthy and M. Levoy, Computer Graphics Proceedings, Annual Conference Series, 1996.
"Photometric Method for Determining Surface Orientation from Multiple Images", R.J. Woodham, pp. 513-531.
"A Theory of Photometric Stereo for a Class of Diffuse Non-Lambertain Surfaces", H.D. Tagare, IEEE Transactions of Pattern Analysis and Machine Intelligence, vol. 13, No. 2, Feb. 1991.
"Modeling the Mighty Maple", Jules Bloomenthal, SIGGRAPH '85, vol. 19, No. 3, San Francisco, Jul. 22-26, 1985.
"Object Representation in Computer Vision II", J. Ponce, A. Zisserman and M. Herbert (Eds.), ECCV '96 International Workshop, Cambridge, U.K., Apr. 13-14, 1996 Proceedings.
"Piecewise Surface Flattening for Non-Distorted Texture Mapping", C. Bennis, J-M. Vezien & G. Iglesias, Computer Graphics, vol. 25, No. 4, Jul. 1991.
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