翻訳と辞書
Words near each other
・ Eight-bar linkage
・ Eight-cell stage
・ Eight-circuit model of consciousness
・ Eight-day week
・ Eight-dimensional space
・ Eight-eight fleet
・ Eight-ender
・ Eight-Foot High Speed Tunnel (Hampton, Virginia)
・ Eight-hour day
・ Eight-in-the-box defense
・ Eight-legged essay
・ Eight-lined wrasse
・ Eight-man football
・ Eight-man football defensive formations
・ Eight-Nation Alliance
Eight-point algorithm
・ Eight-Point Gallery Cafe
・ Eight-point Regulation
・ Eight-spotted skimmer
・ Eight-spotted Skipper
・ Eight-string bass guitar
・ Eight-string guitar
・ Eight-thousander
・ Eight-to-fourteen modulation
・ Eight-vertex model
・ Eight-wheel drive
・ Eightball (comics)
・ Eightball Records
・ Eightball Tasmania
・ Eightband butterflyfish


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Eight-point algorithm : ウィキペディア英語版
Eight-point algorithm
The eight-point algorithm is an algorithm used in computer vision to estimate the essential matrix or the fundamental matrix related to a stereo camera pair from a set of corresponding image points. It was introduced by Christopher Longuet-Higgins in 1981 for the case of the essential matrix. In theory, this algorithm can be used also for the fundamental matrix, but in practice the normalized eight-point algorithm, described by Richard Hartley in 1997, is better suited for this case.
The algorithm's name derives from the fact that it estimates the essential matrix or the fundamental matrix from a set of eight (or more) corresponding image points. However, variations of the algorithm can be used for fewer than eight points.
== Coplanarity constraint ==

One may express the epipolar geometry of two cameras and a point in space with an algebraic equation. Observe that, no matter where the point P is in space, the vectors \overline, \overline and \overline belong to the same plane. Call X_L the coordinates of point P in the left eye's reference frame and call X_R the coordinates of P in the right eye's reference frame and call R, T the rotation and translation between the two reference frames s.t. X_R = R (X_L-T) is the relationship between the coordinates of P in the two reference frames. The following equation always equals to zero because the vector generated from T \wedge X_L is orthogonal to both T and X_L :
:
X_L^T T \wedge X_L - T^T T \wedge X_L = (X_L-T)^T T \wedge X_L = 0

Because I = R^T R , we get
:
(X_L-T)^T R^T R T \wedge X_L = 0
.
Replacing (X_L-T)^TR^T with X_R^T, we get
:
X_R^T R T \wedge X_L = X_R^T R S X_L = X_R^T E X_L = 0

Observe that T \wedge may be thought of as a matrix; Longuet-Higgins used the symbol S to denote it. The product R^T T \wedge = R S is often called essential matrix and denoted with E .
The vectors \overline, \overline are parallel to the vectors \overline, \overline and therefore the coplanarity constraint holds if we substitute these vectors. If we call y, y' the coordinates of the projections of P onto the left and right image planes, then the coplanarity constraint may be written as
:
y'^T \mathbf y = 0


抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Eight-point algorithm」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.