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CUSTOM IMAGE PROCESSING CAPABILITIES IN ARCGIS
Hong Xu a , Peng Gao b
a ESRI, Raster Product Engineer Lead, 380 New York Street, Redlands, CA91765 - hxu@esri.com
b ESRI, Raster Development Lead, 380 New York Street, Redlands,-CA91765 - pgao@esri.com
Commission IV, WG IV/2
KEY WORDS: GIS, Raster, Remote Sensing, Transformation, Geometry, Radiometry, Programming, Open System
ABSTRACT:
The traditional workflow of using remote sensing images in GIS applications is to acquire or purchase processed images and then use
these “ready” images in GIS software. As the development of remote sensing technology, more and more sensors have been invented
and are producing imagery with various camera models. Both imagery providers and GIS software companies are working on
providing ways to make these imagery products available to wide varieties of GIS users in a timely fashion. This paper presents the
open structure in ArcGIS, the commercial GIS software, that allows third parties to add custom image processing functionality to
ArcGIS. With this open structure, ArcGIS software provides a platform that brings remote sensing and GIS application together. The
paper will discuss in details the image processing capabilities in ArcGIS and the open structure that supports custom geodata
transformations, custom pixel filters, and custom raster format into ArcGIS.
1. INTRODUCTION
ArcGIS, the leading GIS software for managing geospatial data,
provides functionality in raster data storage and management,
image processing, image visualization, and image serving over
the web. This combination of capabilities provides a complete
solution for government agencies, the military, private
companies, and many other parties to build various GIS and
geospatial applications.
First, ArcGIS supports more than 40 existing raster formats and
can store large seamless image mosaics in an enterprise
geodatabase and a File geodatabase that any other existing
raster format can not offer. Developers can also add any new
raster format support into ArcGIS. These capabilities have laid
a solid foundation for building geospatial applications with
various image data; Secondly, ArcGIS provides many raster
renderering capabilities that can display various types of raster
data; Thirdly, ArcGIS provides rich raster processing tools for
raster analysis and image processing such as creating a slope or
creating an hillshade image from DEM, generating a pan-
sharpened image, georeferencing an image, creating
orthorectified images from QuickBird and IKONOS’s basic
image products, and so on. Lastly, the ArcGIS server products
allow users to serve imagery through intranet and internet,
providing image services to more users.
As the development of GIS and remote sensing technologies
improve, the demand for imagery as GIS data sources also
increases. More image sensors have been developed and are
producing imagery for various GIS applications (Tao, 2001,
Altimarier, 2002, Toutin, and Wolniewicz et al), and each
sensor might have its own proprietary camera model and/or
image processing algorithms. Making these images available to
vast GIS users using a fast and convenient way becomes critical
for both GIS users and image companies. ArcGIS, as a
complete system for managing geospatial data, has not only the
capabilities to mange, visualize, process and serve images, but
also provides an open structure for developers or third parties to
add their own algorithms for image processing including
geometric transformation and radiometric transformation. Any
third parties can create their own extensions or custom plug-ins
to support custom camera model and custom pixel filtering
algorithms, taking advantages of the powerful ArcGIS
capabilities in image management, mapping and raster analysis.
2. GEOMETRIC TRANSFORMATION SUPPORT IN
ARCGIS
ArcGIS software supports many types of geometric
transformations. The Georeferencing toolbar in ArcGIS allows
users to georeferencing image with three geometric
transformation types: polynomial transformation which includes
1 st , 2 nd , and 3 rd polynomial, rubber sheeting transformation, and
Spline transformation. ArcGIS’s raster projection engine
provides a fast and accurate algorithm for re-projecting images
to various projections including the complicated Cube and
Fuller projections.
ArcGIS also supports reading and processing images with RPC
camera model. Starting from 9.2 release, ArcGIS software,
supports RPC camera model from the basic image products of
QuickBird and IKONOS. The RPC information is read and
applied directly when the image is accessed or displayed in
ArcGIS (Figure 1). Further more, by applying DEM, ArcGIS
can produce orthorectified image from these products (Figure 2,
and Figure 3).