I. ENVI image processing software
General introduction to ENVI software
ENVI (ENvironment for Visualizing Images) is a software product of EXELIS Visual Information Solutions (USA) – http://exelisvis.com – combining advanced techniques in digital image data processing (including remote sensing data, DEM and GIS/GPS) with geospatial analysis technology to exploit valuable information to support accurate and timely decision making. With a modern, easy-to-use interface and outstanding features in image analysis processing that are standardized and regularly developed and upgraded, the ENVI software suite is increasingly becoming an effective geospatial information exploitation tool in multidisciplinary mapping and resource and environment applications.
Outstanding features of the ENVI software suite include:
– Working (displaying and processing) large quantities and sizes of images;
– Read, display and analyze multiple formats of satellite images, popular images, raster data and DEM;
– Exploit information from various types of satellite images and aerial images (VNREDSat-1, SPOT, Landsat, ASTER, QuickBird, GeoEye, WorldView, Radar, Vexcel…);
– Mix image formats (optical images, radar images…) to understand the characteristics of the study area;
– A diverse set of image processing tools based on proven scientific methods such as geometric processing tools, spectrum analysis tools, data analysis tools and advanced tools;
– Ability to work with vector data (shapefile, MIF, DXF and GPS formats) and connect directly to ArcGIS software allowing easy integration of image analysis results into databases and GIS mapping application processes;
– With the IDL programming language, ENVI is customizable and extensible according to the customer’s image analysis processing requirements.
ENVI products
ENVI software suites with hard and soft keys are usually provided packaged according to the following product levels:
– Basic part – ENVI (Runtime) or ENVI+IDL
– Extension modules (on request).
ENVI’s feature extension modules are designed to perform advanced processing methods that require advanced image processing tools, such as:
1. Rigorous Orthorectification module: corrects geometry to ground coordinates and creates orthogonal images with high accuracy. This module is based on a mathematical model using specific sensor parameters (such as SPOT or Landsat sensors) to eliminate image distortion factors during flight capture. Rigorous Orthorectification module allows:
– Easy to use with wizard-based interface for each step in the correction process;
– Working with many types of sensors (e.g. SPOT 1-5, IKONOS-2, QuickBird-2, Landsat 4-5, Landsat 7 ETM+, ASTER, VNREDSat-1…);
– Increased accuracy with the selection of GCPs and common points of adjacent images when processing batches of images;
– Automating the geometric correction process and transferring the results easily to GIS databases.
ENVI Feature Extraction (FX) module: Find, detect and extract information from objects of interest (e.g. buildings, football fields, vehicles, roads, bridges, rivers, lakes…) based on spatial properties, spectral properties or texture properties… from different types of satellite & aerial images. With its customizable capabilities and easy integration with ArcGIS, ENVI FX allows users to change appropriate parameters in complex image analysis processing chains and extract necessary information, such as detecting tanks, military structures or military runways, etc.
ENVI DEM Module: Creates a digital terrain model (DEM) from stereo image pairs (ASTER, IKONOS, OrbView-3, QuickBird and SPOT 1-5 satellite images) or aerial photos. With its customizable capabilities, users can interactively view stereo image pairs, measure the height of buildings or mountain peaks, edit DEM values and extract 3D objects.
4. ENVI Atmospheric Correction Module (ACM): Performs procedural preprocessing – allowing for the removal or in-depth correction of atmospheric effects on original satellite images to create remote sensing images at a higher level, preparing them for further analysis processing steps. ENVI ACM allows for quick (on-the-fly) correction using the QUAC method and advanced correction based on the photophysical model – the FLAASH method for most types of satellite images commonly used today. This module is necessary for applications that monitor changes in terrain or groups of objects quantitatively.
5. ENVI NITF module: Read, edit and distribute remote sensing images in the NITF format with high image compression efficiency. The NITF format contains image data with graph data and metadata according to the JITC (Joint Interoperability Test Command) standard. This is an optimal format with good image compression ability, high security, so it is often used for national and defense data…
6. Specialized product ENVI LIDAR: In-depth processing of lidar data to identify and extract 3D objects and create 3D GIS databases for urban or forestry applications.
Software ENVI LIDAR allows users to process cloud data
LiDAR points to detect and extract 3D objects such as trees, power lines, construction works with elements such as house frame and roof shapes, digital elevation models, etc. ENVI LIDAR combines automatic recognition with interactive tools so that users can adjust processing parameters to control the quality of the resulting products. With 3D display function and direct connection to ArcGIS, ENVI LiDAR has the ability to connect well with other geospatial analysis processing systems, the ability to expand customization through API and read all popular LIDAR data formats such as LAS, LAZ, ASCII, NITF LAS, etc.
Specialized product ENVI SARScape: In-depth processing of radar image data, analysis and creation of DEM maps and surface change maps.
ENVI SARscape software allows users to process and interpret ambiguous radar data into meaningful information appropriate to the context. The SARscape Basic & InSAR Bundle license includes 2 modules:
– SARscape Basic allows reading and processing radar image data such as advanced filtering, image correction and stitching, creating multilook images… to image classification, object recognition or change tracking…
– SARscape Interferometry (InSAR) allows processing pairs of interferometric radar images to create DEM data and map displacement and surface deformation (update topographic, geomorphological and landslide maps).
In addition, Exelis VIS has recently developed a specialized product ENVI for ArcGIS to integrate with ESRI’s GIS solution and ENVI in the Cloud to manage and share image analysis processing resources on the Cloud for businesses and individuals.
II. ArcGis image processing software
ArcGIS (ESRI Inc. – http://www.esri.com): is the leading GIS system today, providing a comprehensive solution from data collection / input, editing, analysis and information distribution on the Internet to different levels such as personal geographic databases or enterprise databases. In terms of technology, GIS experts currently consider ESRI technology to be an open, comprehensive and complete solution, capable of exploiting all GIS functions on different applications such as: desktop (ArcGIS Desktop), server (ArcGIS Server), Web applications (ArcIMS, ArcGIS Online), or mobile device systems (ArcPAD) … and has high compatibility with many types of products from many different manufacturers.
ArcGIS Desktop (with the latest version being ArcGIS 10) includes very powerful tools for managing, updating, analyzing information and publishing to create a complete geographic information system (GIS), allowing:
Creating and editing integrated data (spatial data integrated with attribute data) – allowing the use of many different data formats, even data taken from the Internet;
Querying spatial data and attribute data from many sources and in many different ways;
Displaying, querying and analyzing spatial data combined with attribute data;
Creating thematic maps and professional quality prints.
ArcGIS Desktop is a suite of application software including: ArcMap, ArcCatalog, ArcToolbox, ModelBuilder, ArcScene and ArcGlobe. Using these applications together, users can perform any GIS application tasks, from simple to complex, including mapping, geographic analysis, data editing and manipulation, data management, data display and processing. ArcGIS Desktop software is provided to users at 1 of 3 levels with different levels of expertise: ArcView, ArcEditor, ArcInfo:
ArcView: Provides full functionality to represent, manage, build and analyze geographic data, spatial analysis tools along with editing and analyzing information from different map layers while showing relationships and identifying models. With ArcView, it allows:
Make more accurate decisions based on geographic data;
View and analyze spatial data using multiple methods;
Build geographic data simply and easily;
Create high-quality maps;
Manage all files, databases, and data sources;
Customize the user interface as required.
ArcEditor: A more functional product suite for editing and managing geographic data. ArcEditor includes the features of ArcView and adds a number of editing and editing tools. With ArcEditor, you can:
Use CAD tools to create and edit GIS features;
Create intelligent geographic databases;
Create professional workflows for a team and allow multiple editors;
Build and maintain spatial integrity including topological relationships between geographic features;
Manage and extend geometric networks;
Increase editorial productivity;
Manage multi-user design environments with versioning;
Maintain integrity between subject layers and promote logical thinking of users;
Enable independent data editing (when disconnected from the database).
ArcInfo: The most complete ArcGIS product suite. ArcInfo includes all the functionality of ArcView and ArcEditor. Provides functions for creating and managing a GIS, processing spatial data and data transformation, building data, modeling, analyzing, displaying maps on the computer screen and publishing maps to different media. With ArcInfo, you can:
Build a spatial processing model that is very useful for finding relationships, analyzing data and integrating data;
Perform vector layer overlays, interpolation and statistical analysis;
Create features for events and overlay features of those events;
Convert data and data formats into a variety of formats;
Build complex data sets, analytical models and scripts to automate GIS processes;
Use presentation, design, printing and map management methods to publish maps.
