1SPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001
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DIGITAL CLOSE RANGE PHOTOGRAMMETRY: A POTENTIAL TOOL FOR LAND FEATURE PRESENTATION
Gang DENG
Division of International Cooperation, Kunming University of Science and Technology
121 Street, Kunming P.O. 650093, CHINA, Tel/Fax: +86-871-519-8622, Email: qdenq@oublic.km.yn.cn
KEYWORDS: Digital close range photogrammetry, GIS, feature presentation
ABSTRACT
Digital close range photogrammetry (DCRP) provides one of the most generally welcome ways for land feature presentation for GIS
software package. This is made possible with the successful development of DCRP in recent years. In addition to a simple image
viewing for retrieval, a number of more functions could be expected by merging DCRP into GIS, including geometric measurement
directly on photos and in 3D view, 3D model construction and virtual reality animation, etc. These are introduced with the applications of
a successful and award winning DCRP software package PhotoModeler Pro as an example. Some related concerns are discussed.
INTRODUCTION: User friendly is a general demanding for any
GIS software package. For the vast variety of users, the intuitive
presentation of a spatial entity with the form of the direct image
as seen in real life would be most generally welcome and
acceptable. It is therefore a natural choice for GIS software to
take advantage of the digital images of spatial entities or land
features as a helpful source to satisfy the corresponding retrieval,
and conduct the other operations, necessary overlay analysis for
instance. Image viewing has been incorporated into some GIS
software, but it is a waste of the image data sources if the digital
images are only employed for a viewing based on the retrieval
query. Many other functions can be accomplished with the help
of DCRP software by processing the digital images
photogrammetrically in advance and incorporating the results of
processing into GIS. From the pre-processed imagery, direct
measurement could be made on the digital photograph, Ortho
photo could be obtained for the selected plane of the object on
the image, 3D model could be constructed and 3D measurement
made directly on the model, engineering drawings of the
architectural structure on the image could be derived, and even
animation tour of the street could be accomplished with a virtual
reality computer model. The above functions in different DCRP
application cases were accomplished using a DCRP software
package named PhotoModeler Pro (PM Pro) developed by the
EOS Company, Canada (EOS, 1997). In this paper, these
functions achieved by PM Pro are briefly introduced, and some
related concerns are discussed.
PhotoModeler Pro (PM Pro) is a 32-bit windows program that
runs on Windows 95+ and NT4.0+. It support images lager than
16 MB (EOS, 1997). Among its other features and for GIS
applications, this package is characteristic in the multiple format
input and output, including many commonly seen image formats
as image input, ortho-photo output and 3D model output with or
without photo-texture; 3D object space measuring on a digital
photograph or in a 3D view. The latest version of PM Pro is
version 4.0 released about half a year ago. The author was able
to make a photogrammetric evaluation of the version 3.0j, with
different non-metric images of two different objects (Deng, 2001).
The conclusions of the evaluation are promising. The
applications to the wooden house introduced below are from the
test in the evaluation made by the author, while the other two
application cases are from the current web site of PhotoModeler
(http://www.Photomodeler.com).
POTENTIAL APPLICATIONS OF DCRP IN GIS: For merging
DCRP into GIS to represent spatial entities, two types of general
applications can be expected, namely the intuitive image viewing
with the forms of the original image (no photogrammetry is
necessarily needed at this stage), ortho-photo and/or 3D model
with or without photo texture, and the extraction of the
geometrical information from the digital image or the 3D model
constructed by DCRP. By making use of the DCRP software
package PM Pro, all these functions were illustrated in different
projects of DCRP. They are unfortunately not all seen yet in GIS,
the author however, believes and would like to recommend
these functions be incorporated into GIS in the near future.
1. Intuitive Viewing of the Photos: a. Viewing the original
image: This is the most simple and direct way of utilizing digital
image data in a GIS package, and no photogrammetry is
necessarily needed for this function. As a typical raster
presentation of spatial features, digital images can be directly
introduced into any GIS as a specific layer for retrieval, and it is
not uncommon in the current GIS packages. In the GIS package
