Automatic extraction of the representative 2-D projected shape for polyhedral object from viewing vector map
✍ Scribed by Kozo Fujimoto; Masato Kimoto; Shuji Nakata
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 773 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0882-1666
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Two‐dimensional (2‐D) projected image (object appearance) pictured by a TV camera is changed by the construction of the visible surfaces or the surface occlusion according to the view direction. This paper proposes a new algorithm for extracting the representative 2‐D projected shape. In this method, a viewing area showing the same appearance is drawn and expressed on a viewing vector map that is the orthogonal coordinate graph expressed by the deflection angle (α, β) of a viewing vector in a polar coordinate system. A viewing vector map is divided into the viewing regions showing the same appearance by drawing the visible region of each surface and the boundary line showing the occlusion between surfaces.
The representative 2‐D projected shapes for the 3‐D object are obtained by extracting the representative points in each divided region on a viewing vector map. The representative projected shape for a stable postrue of the 3‐D object is extracted easily by drawing the trace of the viewing point based on a stable posture of the object and the position of the TV camera on a viewing vector map. Furthermore, the approximate ratio of each viewing region showing the same appearance to the 3‐D view space can be calculated easily. This ratio shows the appearance probability.