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Next: Affine Multiple Views Geometry Up: Camera Models Previous: The Weak-Perspective Camera

The orthographic camera

The affine camera reduces to the case of orthographic (parallel) projection when ${\bf M}$ represents the first two rows of a rotation matrix. The simplest form is

\begin{displaymath}
{\bf T}_{orth} =
\left[ \begin{array}{cccc}
1 & 0 & 0 & 0 \\
0 & 1 & 0 & 0 \\
0 & 0 & 0 & 1 \\
\end{array} \right]
\end{displaymath}

yielding,

\begin{displaymath}
{\bf M}_{orth} = \left[ \begin{array}{ccc}
1 & 0 & 0 \\
...
...ht]
=
\left[ \begin{array}{c}
X \\ Y
\end{array} \right]
\end{displaymath}

Figure 1: 1D image formation with image plane at $Z = f$. $X_p,X_{wp}$ and $X_{orth}$ are the perspective, weak-perspective and orthographic projections respectively.
\begin{figure}\centerline{\psfig{width=5.0in,figure=models.ps}}\end{figure}



Subhashis Banerjee 2002-02-18