3D RECONSTRUCTION OF THE SOLID OF ROTATION LACKING IN TEXTURE
: : a. * Ta ê 7 2
Jianging Zhang *^', Jun Tao*, Zuxun Zhang *
? Wuhan University, College of Remote Sensing and Information Engineering,
#129 Luoyu Road, Wuhan, Hubei, P.R.China
Jqzhang@supresoft.com.cn, martintao@etang.com, zxzhang@supresoft.com.cn
KEY WORDS: Reconstruction, Three-dimensional, Image, Texture, Camera, Platform, Adjustment, Photogrammetry
ABSTRACT:
The paper proposed an approach to reconstruct the solid of rotation lacking in texture from two-dimensional images. The approach
only requires a digital camera, an ordinary slide projector and a rotated platform. The camera and prôjector are required to be
calibrated in advance. The rotated platform is functioned as a control ground and the target object is put on it. The projector projects
the slide points onto the solid of rotation so that the texture is supplied to the surface of it. The digital camera takes sequential images
with these points when the platform rotates continually. For each space feature point projected on the surface of the solid of rotation,
there are two corresponding 2D points existing. One is an image point in one of the image sequences and another is a point within
the slide points. Gotten the two 2D coordinates of the points, the 3D coordinates of the space points on the surface of the solid of
rotation can be calculated by the collinear equations. The sequential images are taken from different directions of the solid of
rotation. Using the correspondence of whole adjustment and the inherent structure characteristic of the solid of rotation, the 3D
coordinates of all space points projected on the whole surface of the solid of rotation can be computed out entirely. The 3D model of
this solid of rotation is acquired by connecting all neighbour space points. This approach is flexible and practical, which are
confirmed by the results of the reconstructing experiments.
1. INTRODUCTION
1.1 3D Reconstruction
3D reconstruction is referred as a process of the recovery of
three-dimensional model from the two-dimensional digital
camera images. During the image formation process of the
camera, explicit 3D information about the scene or objects in
the scene is lost. Therefore, 3D model or depth information has
to be inferred implicitly from the 2D intensity images. The key
of the traditional method lies in the matching of the
corresponding features in the images. When there is no feature
or lack of feature in the objects, or when the features cannot be
matched correctly at all, the main problems appear in the
process of the 3D reconstruction
The paper provides a method to resolve the problems above. It
is an ordinary slide projector that can supply any feature what
you want to the target objects. These features are easy to be
controlled and to be extracted out, which has paved the
convenient path for the matching of them. According to the
demand and real condition, the features can be changed or
adjusted.
The paper explains clearly how to use the ordinary slide
projector and how to apply it to the applications of the 3D
reconstruction, too.
1.2 Definition of the Solid of Rotation
In the real world, there exist many things being the solid of
rotation or being component of several solids of rotation, such
as: Ball, Cup, flowerpot, jug, pencil and cap, even dome. So the
solid of rotation is a common thing and it is necessary to
research its 3D reconstruction.
General definition of the solid of rotation is that the main body
of the target objects can be formed by a curve rotating around a
fixed axis.
The paper mainly researches the 3D reconstruction of the main
body. Namely, the target object is only a simple solid of
rotation and it has no other component with it. This kind of
object has an obvious characteristic that each vertical section of
the fixed axis is a circle.
1.3 Overview of the Paper
In the last few years the interest in three-dimensional object
reconstruction from two-dimensional images has dramatically
increased in the field of photogrammetry. The main difficulties
lie in the texture feature extraction and the model acquisition
with time-consuming and expensive process, especially the
reconstructed object lacking in texture. An approach is
proposed in this paper, which avoids most of the problems
mentioned above. The target object needed reconstructing is
given emphasis on the simple solid of rotation.
When three positions of the camera, the slide projector and the
rotating platform are adjusted to the suitable place, the solid of
rotation is put on the centre of the rotating platform. The
projector projects a feature slide onto the solid of rotation so
that the texture is supplied to the surface of it. According to the
different demand and condition, the feature slide can be
designed differently. Then the digital camera takes sequential
images with projected feature slide when the platform rotates
by an angle continually.
* jgzhang@supresoft.com.en; Tel: 86-27-87561116; Fax: 86-27-87561011
162
International
For each spac
solid of rotatic
One is an ir
another is a p
method, the 2
can be worke
projected is d
point within tl
the 3D coord
solid of rotatic
The sequentia
solid of rotatic
and the inhere
the 3D coordi
surface of the
The 3D mo
connecting al
reconstruction
2. "M
2.4 Backgro
2.1.1 Thec
The digital ca
the late comp
requires the i
camera. There
important prec
Direct Linear
used in close-i
initial value o
existed camer
The restricting
out using the c
The decompo
extrinsic para
camera calib
addressed. S
accomplished
of the digital «
Zhang, and Y«
If the camere
measuring-car
the intrinsic p
the known dat
camera are Stil
212. Thec
In this appro
makes the sar
slide projecto
intrinsic and
computation p
The algorithm
and collinear
algorithm is a
First, the im:
carefully and
computed by
parameters of
