image analist

ArcView Image Analysis Extension(Version 1.1)

An ERDAS ® and ESRI

® White Paper • September 1999

Copyright © 1998, 1999 ERDAS, Inc. All rights reserved. ERDAS and ERDAS IMAGINE are registered trademarks and geographicimaging made simple is a service mark of ERDAS, Inc. The names of other companies and products herein are trademarks orregistered trademarks of their respective trademark owners.

The information contained in this document is the exclusive property of Environmental Systems Research Institute, Inc. This work isprotected under United States copyright law and other international copyright treaties and conventions. No part of this work may bereproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or by anyinformation storage or retrieval system, except as expressly permitted in writing by ERDAS, Inc. All requests should be sent toAttention: Corporate Communications Manager, ERDAS, Inc., 2801 Buford Highway Northeast, Atlanta, GA 30329-2137, USA.

The information contained in this document is subject to change without notice.

The names of other companies and products herein are trademarks or registered trademarks of their respective trademark owners.

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ArcView Image AnalysisExtension (Version 1.1)

An ESRI White Paper

Contents Page

Product Overview 1Product Design Concept 1Product Positioning 1Target Markets and Solutions 2

Forestry/Natural Resources Management 3Agriculture 3Infrastructure Management/Environmental Engineering 4Environmental Planning 5Map Updating and Temporal Analyses 6

Key Features Summary 7

Functional Description 8Access to Industry-Standard Image Data Types and Formats 8Fast Image Display and Manipulation 9Three Levels of Image Enhancement Utilities 9Spatial Enhancement Filters 9Image-to-Map Registration 10Mosaicking 10Image Analysis Tools 11ArcView GIS Integration Tools 11

Platform Support 12

Contact Information 12

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ERDAS and ESRI White Paper

ArcView Image AnalysisExtension (Version 1.1)

Product Overview Imagery of the earth's surface, both aerial and satellite, is becoming anintegral part of today's geographic information systems (GIS) and desktopmapping systems. The ArcView® Image Analysis extension provides thetools necessary for ArcView GIS users to take full advantage of the widerange of digital image data that is available today or planned for in thenear future. This includes aerial photography and digital orthoimagery ofall types, as well as current and future small-, medium-, and large-scalesatellite data.

The ArcView Image Analysis extension is an ERDAS® product and is the result of acollaborative effort between ESRI and ERDAS, intended to bring key elements ofERDAS's geographic imaging capabilities into the ArcView GIS environment.

Product DesignConcept

The ArcView Image Analysis extension is a simple and intuitive complement to ArcViewGIS. The design concept has three components:

■ Provides a set of tools for incorporating imagery from a wide range of sources intoany ArcView GIS application or work flow.

■ Provides these tools in a way that is exceedingly easy to use by any ArcView GISuser, regardless of skill or experience with image processing or remote sensing.

■ Complements the existing capabilities of ArcView GIS, ArcView Spatial Analyst,and the ERDAS IMAGINE® suite of software. Data flow between ArcView GIS,the ArcView Image Analysis extension, the ArcView Spatial Analyst extension, andERDAS IMAGINE is direct and transparent to the user.

Product Positioning The ArcView Image Analysis extension enhances the overall ArcView GIS suite ofsoftware packages and solutions by providing access to key image display, enhancement,and analysis tools for any work flow.

The software is positioned as an entry-level geographic imaging/remote sensingcapability for the ArcView GIS user who may not have extensive imaging experience.The interface is designed specifically with ease of use in mind.

With the introduction of the ArcView Image Analysis extension, ERDAS and ESRI areproviding ArcView GIS users with entry-level imaging capabilities and a growth path forgeographic imaging. ArcView Image Analysis is a step up from the current imagedisplay and theme capabilities of ArcView GIS, while ERDAS IMAGINE is a moreadvanced suite of products designed to achieve a broader range of sophisticated remote

ArcView Image Analysis Extension (Version 1.1)

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sensing. The positioning of ArcView GIS, the ArcView Image Analysis extension, andERDAS IMAGINE is diagrammed below.

The ArcView Image Analysis extension provides a set of tools for custom applicationdevelopment with Avenue™ software for industries and applications such as agricultureand forestry that require easy access, manipulation, and analysis of image data.

This extension combines with ArcView Spatial Analyst, ArcView 3D Analyst™, andArcView Tracking Analyst software to create a powerful suite of optional extensioncapabilities for resource management, infrastructure management, emergencymanagement, extractive industries, mapping, and a host of other applications.

Target Marketsand Solutions

One of the keys to the effective use of digital image data is the management and handlingof extremely large data files. The ArcView Image Analysis extension is designed tomanage, display, and manipulate image data files of any size easily within theArcView GIS project environment. The user interface provides a simple means tocapture map information from imagery to feed both ArcView GIS projects and spatialmodels in ArcView Spatial Analyst. This extension is designed to facilitate work flowsbased on image interpretation such as map creation/map edit, qualitative analyses of theearth's surface, quantitative analyses, and temporal analyses and change detections.

The potential uses of both imagery and the ArcView Image Analysis extension within theArcView GIS environment are nearly limitless. However, ArcView Image Analysis isdesigned primarily for natural resources applications such as forestry and agriculture,environmental assessments of all types, engineering and infrastructure managementprojects, and the general scenario of GIS map database updating and maintenance. Thefollowing are representative selections of target markets and applications.

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Forestry/NaturalResources

Management

The ArcView Image Analysis extension provides imaging tools to support a range ofproject and production requirements for the forest industry. This new imagingenvironment provides a range of simple and robust analysis tools for monitoringvegetation conditions, biomass and biodiversity, and changes over time for incorporatingresults directly into ArcView GIS and ArcView Spatial Analyst. Typical activities thatmake use of aerial and satellite imagery include

■ Baseline inventories■ Harvest planning and management■ Road siting and design■ Pest management■ Recreation planning■ Lease management■ Environmental compliance■ Habitat management

Agriculture For agricultural applications, the ArcView Image Analysis extension providescapabilities for broad-area monitoring of crop area and condition, as well as farm-specificassessment of crop conditions from imagery. This data and derived information may thenbe used as input to systems for management planning in precision farming,environmental assessments for erosion and nonpoint source pollution, and crop insurance.Typical applications include

■ Broad-area crop monitoring■ Suitability analysis■ Crop stress detection■ Erosion management■ Crop insurance

Forest inventory andharvest management


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InfrastructureManagement/

EnvironmentalEngineering

One of the primary uses of the ArcView Image Analysis extension is in engineering andinfrastructure-related projects. Both satellite and aerial imagery are integral parts tomany civil engineering, land development, and environmental projects. ArcView ImageAnalysis facilitates work flows in the planning, design, and operations and maintenanceareas of a typical engineering project life cycle. This includes broad-area planning usingcommercial satellite data combined with ancillary data in ArcView GIS, landsuitability/capability assessments, alternative route selections, basemapping and planupdating, surveying and cadastral mapping, design reviews, and temporal monitoring fordatabase maintenance purposes.

In conjunction with ArcView Spatial Analyst, ArcView Image Analysis provides acomplete set of simple, intuitive image and raster analysis and modeling tools for theArcView GIS environment. Capabilities allow you to perform

■ Alternative site selection■ Site characterization■ Hydrologic analyses■ Environmental compliance■ Hazard mapping and monitoring

SoilSamples

Crop condition and stress analysiscombined with soil and yield data


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EnvironmentalPlanning

A key range of applications for which ArcView GIS is well suited is those relating toenvironmental planning and monitoring. ArcView Image Analysis adds significant valueand capability to the ArcView GIS suite of tools. Imagery is particularly suited forprojects involving the mapping and monitoring of environmentally sensitive areas.ArcView Image Analysis provides key analytical tools for capturing image-derivedinformation.

Applications for environmental planning include

■ Wetland mapping and monitoring■ Critical area assessment■ Environmental impact assessment■ Hazardous waste and spill monitoring■ Site characterization

Oil spill mapping with radarimagery

Alternative route selectionfor transportation corridor


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Map Updating andTemporal Analyses

One of the most anticipated uses of the ArcView Image Analysis extension is for GISbasemap updating from digital orthophotos or satellite orthoimages. The softwareprovides an efficient means of displaying and enhancing imagery and performing simpleanalyses, heads-up digitizing, automated change analysis, and map editing in a productivemanner.

Flood mapping damageassessmentWetland mapping


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Key FeaturesSummary

■ Access to industry-standard image data types and formats■ Fast image display and manipulation■ Flexibility for setting and managing user preferences■ Mosaicking data in a simple, single-button operation■ Three levels of image enhancement utilities■ Spatial enhancement filters■ Image-to-map registration■ Image analysis tools■ ArcView GIS integration tools■ Customization with Avenue

Urban land conversionand growth analysis

Date 1

Date 2


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FunctionalDescription

Access to Industry-Standard Image Data

Types and Formats

There are two mechanisms for accessing data with the ArcView Image Analysisextension. First, a set of importers is provided for commercially available satellite andgovernment image data. This imports data into the .img (ERDAS IMAGINE) format forfurther use. The importers included in version 1.1 are listed below. Over time, this listwill be extended, based on user requirements, to include a broader range of image dataformats.

The second mechanism is the ability to directly read data in an ERDAS IMAGINE .img,grid, or GeoTIFF/TIFF format and use it without conversion. This allows for bothreading and writing of data and gives the user the ability to access data, use it within aproject, and write it out to either of the other two formats. In addition, there is read-onlyaccess to ERDAS .lan and .gis data, BIL, BIP, BSQ, JPEG, ERMapper, NITF, as well asMrSID™.

■ Direct read and write

• ERDAS IMAGINE .img• Grid• GeoTIFF or TIFF

■ Direct read-only

• LAN• GIS• MrSID• Raw data in BIL, BIP, and BSQ formats• ERMapper• NITF• JPEG

■ Importers

• Landsat TM (including Landsat 7)• SPOT• DOQ (Digital Orthophoto Quads from the U.S. Geological Survey)• RPF• CIB• CADRAG• IRS-1C• RADARSAT• ERS• NLAPS


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Fast Image Displayand Manipulation

One of the keys to the effective use of digital imagery is the ability to display andmanipulate data rapidly. Image data is often large files in the order of tens to hundreds ofmegabytes each. The ArcView Image Analysis extension provides a fast image displaycapability from the ERDAS IMAGINE environment that will support rapid, interactiveviewing and control of large image files. This feature will substantially enhance anyArcView GIS project that incorporates imagery as an element of the work flow.

■ Imaging display engine with pyramid layers, tiles, and so forth.■ Single-button band selection and enhancement of multiband image data■ Interactive capabilities

• Viewing and editing of multiband default settings• Data subsetting• Selectable band combinations• Query/Display of pixel attributes• Measurement capabilities

Three Levels ofImage Enhancement

Utilities

A key to extracting usable information from imagery for any ArcView GIS project is theability to enhance the interpretability of the data for features or areas of interest. Mostimage data types have a dynamic range and contrast that is less than that of a typical 8-bitcomputer display. To compensate, imagery must be "stretched" such that the dynamicrange and contrast/brightness are increased to take full advantage of the informationcontent of the data. ArcView Image Analysis provides three levels of brightness/contrastand histogram stretch controls. These offer a range of simple slider controls and one-button stretches, as well as sophisticated histogram controls designed to make it easy tovisualize and interpret image data for specific mapping requirements.

■ Brightness and contrast control■ Standard one-button histogram stretches

• Standard deviation• Histogram equalization• Minimum–Maximum• Gamma stretch• Gaussian stretch

■ Custom stretches with advanced lookup table editor

Spatial EnhancementFilters

Spatial enhancements are designed to alter the appearance of image data for the purposeof interpreting or preserving one or more types of features. Filter tools in this extensionare designed for ease and speed of use. These include edge enhancement for linearfeature mapping, such as roads or other man-made features, and low pass/focal majorityfor feature averaging, which is useful in minimizing the "speckled" appearance ofselected data types.

■ Single-button edge detection■ High-pass sharpening■ Low-pass smoothing■ Focal-majority


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Image-to-MapRegistration

One of the most useful tools in the ArcView Image Analysis extension is the Image Aligntool, which is designed to coregister image data to map themes or even to other images.The intuitive point-marking scheme is designed to make image rectification simple forthe first-time user. In addition to the standard rectification process from user-definedcontrol points, the software automatically displays selected satellite data types in a propermap position. This capability is known as image calibration and is based on positionalinformation (ephemeris) provided with selected commercial data sources.

■ View and edit the default settings for resampling algorithms for image display andimage file creation. Options include

• Nearest neighbor

• Bilinear interpolation

• Cubic convolution

■ Automatic image calibration from satellite ephemeris data.

■ Easy-to-use image alignment point-marking process for matching imagery toshapefiles and coverages including GPS-collected points.

■ On-the-fly approach for simple image alignment without complex control point errortables.

■ Automatic calculation and selection of best first or second order polynomial fit.

■ Save alignment geometry for use with ERDAS IMAGINE.

■ Image-to-image registration for multidate sequences of imagery.

Mosaicking ArcView Image Analysis 1.1 is significantly enhanced with new mosaicking capabilitiesthat are easy to use and understand and enable you to automatically combine multipleimage files into a single file. Key features of this capability include the following:

■ Mosaic multiple image files into a single image file, including both single-bandpanchromatic and multiband color continuous imagery from aerial or satellitesources, as well as thematic image data such as thematic class maps from multipleimage sources.

■ Simple user operation that is "what you see is what you get" in nature. Imagesdisplayed in a view are mosaicked in a single-button operation.

■ Images with different pixel sizes can be mosaicked into any user-selectable outputpixel size using the ArcView Image Analysis Properties dialog.

■ Front-to-back ordering of the input images is selectable via the Table of Contents.

■ Histogram stretches of the input images are preserved in the output mosaic.


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■ Define output mosaic boundaries based on shapefile input via the ArcView ImageAnalysis Properties extent and mask functions.

Image Analysis Tools The ArcView Image Analysis extension includes a rich selection of analysis tools. Theseprovide a range of semiautomated capabilities designed to interpret and extract usableinformation from aerial and satellite image data. These functions are designed primarilyas one-button operations, with an automated setup of potentially complex analyses. Theobjective is to provide a simple interface and data flow for interpreting and capturing mapinformation from a wide range of commercially available image sources.

■ Spectral categorization

• Unsupervised approach with ISODATA classifier.• Find like areas for single class/feature identification.• Postclassification aggregation with focal-majority filtering.

■ Automated analysis tools

• One-button vegetation index, using the normalized difference vegetation indexapproach.

• Region growing for single feature boundary mapping.

■ Change detection with automatic setup controls.

• Between continuous tone images and/or vegetation indexes.• Stack image bands from two different images within a single theme.• Between thematic image maps

♦ Identify all combinations of change.♦ Summarize changes of interest.

ArcView GISIntegration Tools

■ Raster-to-vector shapefile conversion.

■ Save results as a grid for use in ArcView Spatial Analyst.

■ Use of grid files in ArcView Image Analysis tasks.

■ Use of all ArcView GIS capabilities and commands for legends, preferences, tables,and layouts.

■ Customization with Avenue.


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Platform Support ArcView Image Analysis 1.1 requires ArcView GIS 3.1 or higher and is delivered on asingle CD. ArcView Image Analysis is available for Windows® (95/98, NT 4.0, andWindows 2000 on Intel®-architecture PCs).

Contact Information For more information about ArcView Image Analysis in the United States, contact ESRIor your local reseller. Outside the United States, contact ERDAS or your localdistributor.

For inquiries within theUnited States, pleasecontact ESRI or yourauthorized reseller.

For inquiries outsidethe United States, pleasecontact your local ERDASdistributor.

ESRI380 New York StreetRedlands, California92373-8100, USATelephone: 909-793-2853Fax: 909-793-5953

For more information onESRI GIS software call

1-800-447-9778(1-800-GIS-XPRT)

Send E-mail inquiries [email protected]

Visit ESRI's Web page atwww.esri.com

ERDAS Worldwide Headquarters2801 Buford Highway NortheastAtlanta, Georgia30329, USATelephone: +1-404-248-9000Toll Free: +1-877-GO-ERDAS (+1-877-463-7327)Fax: +1-404-248-9400

ERDAS in Europe, Africa, Middle East,Asia/Pacific Rim

Telford HouseFulbournCambridge CB1 5HBUnited KingdomTelephone: +44-1223-881774Fax: +44-1223-880160

All Other Worldwide InquiriesTelephone: +1-404-248-9000Fax: +1-404-248-9400

For more information aboutGeographic Imaging, visit theERDAS Web site atwww.erdas.com

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