Achieving the metric calibration

Let the Euclidean camera projection matrices be tex2html_wrap_inline96 and tex2html_wrap_inline98 .

Since tex2html_wrap_inline100 , by comparing

Euclidean equations:


Projective equations:


we have


3D reconstruction after going back to Euclidean space

The Euclidean projection matrices are available HERE for the first image and THERE for the second image. The Euclidean structure of the bi-plane object is available HERE for the first image.

Back projection of the Euclidean reconstruction onto the first image


Orthographic projection of the Euclidean reconstruction on to a plane orthogonal to both planes of the calibration apparatus


The result is not perfect, but this is because the image of the calibration apparatus is very small, and that the corner points cannot be precisely localized. We are happy with this result :-) remembering that the classical calibration technique does not provide any useful results. A more reasonable example is shown here.

Author: Zhengyou Zhang

Thu Oct 10 15:49:19 MET DST 1996