Name: 
IDRISI32 (version I3201 –  updated to I3205 with download ‘patch’)

Released:
2000

Developer:
Clark Labs, Clark University
950 Main Street
Worcester, MA 01610-1477 USA 
Phone: 1-508-793-7526
Web: http://www.clarklabs.org
E-Mail: IDRISI@clarku.edu

Cost:
$1500 – Commercial/Private Single User license (pricing dependent on academic, non-profit, government, commercial, private, student/school educational license, number of licenses)

Distribution: 
CD-ROM

Hardware Requirements:
l Pentium II/III -based PC
l Windows 95, 98, NT (3.5+), 2000
l 16Mb RAM (minimum. 32+ recommended)
l Display size of 800 x 600 with SVGA resolution (1024 x 768 + with 64,000 colors)
l 80-90Mb hard disk space (additional space required dependent upon user’s datasets)
l All graphics adapters and printers (an ink-jet color printer) supported by MS Windows
 
 

IDRISI32 (32-bit object-oriented system) is the most recent release of the integrated GIS and Image Processing software package, IDRISI, from Clark Labs, Clark University in the USA. Earlier releases ran under the MS-DOS operating system (Versions 2.4-4.1) and later MS Windows (Versions 1 and 2). It has now been re-written from scratch to accommodate IDRISI’s growing user base and new developments in the geospatial technologies, advances and updates of computer operating systems, and the associated software. In so doing, it has built upon the past, taking into account user requirements for geospatial data input, analysis, display and output. Additions and improvements that have been included are a real-time interface with GPS, improved map composition capabilities, and more advanced functionality to take on-board new developments and growing end-user demands to meet the needs of applications. Links to the industry standard Gstats routines are also included.

Features
The basic data handling toolbox of IDRISI32 consists of the following:

Performance

Computer Hardware
This review of the IDRISI32 software was conducted on MS Windows NT on a networked (Ethernet) Grampian Electronics (GE) Intel Pentium III 600 MHz processor with 128Mb RAM, a 20 GB hard disk, standard 3.5"floppy drive and a CD-ROM. The display monitor used was a 17" CTX color monitor, with the screen resolution set to 1240 x 1024 pixels. An Epson 440 color ink jet printer and a networked Epson BPL5700 black and white laser printer were the hardware peripherals attached to the system.

Datasets
The datasets used for this review were all included as part of the tutorials provided by IDRISI, except for a single Landsat TM .IMG file originating from IDRISI for MS-DOS, a .TIF image file created in Paintshop Pro, a .JPG from an Olympus C-420L digital camera, a GeoTIFF (originating as an exported .IMG file from ERDAS Imagine) and an ArcView .SHP file of UK census ward boundaries for the County of Surrey.

Operations
The entire IDRISI Tutorial and accompanying raster and vector datasets provided the basis for this evaluation. All the exercises undertaken proceeded without any difficulty, and overall the software performed well on the system upon which it was installed.

Documentation

The documentation included in the box from Clark Labs included the following manuals: 

• Reference Guide: Introduction; Acknowledgements; Dedication; International Resource Centers; The Clark Labs Staff, Contacting Clark Labs, Distributed Materials, Installation, Product List
• Tutorial: Using IDRISI Exercises; Introductory GIS Exercises; Advanced GIS Exercises; Introductory Image Processing Exercises; Advanced Image Processing Exercises; Database Development Exercises.
• Guide to GIS and Image Processing Volume 1: Introduction; Introduction to GIS; Introduction to Remote Sensing and Image Processing; IDRISI System Overview; Map layers, Collections and Data Structures; Display System; Database Workshop; IDRISI Modules; Creating Macros; Database Development; Georeferencing; Appendices: Reference Ellipsoids, Moldensky Constants for Selected Geodetic Datums, Supplied Reference System Parameter Files
• Guide to GIS and Image Processing Volume 2: Decision Support; Image Restoration; Fourier Analysis; Classification of Remotely Sensed Imagery; RADAR Imaging and Analysis; Vegetation Indices; Time Series/Change Analysis; Anisotropic Cost Analysis; Surface Interpolation; Triangulated Irregular Networks and Surface Generation; Geostatistics; Appendix: Error Propagation Formulas

The text offers useful advice to the end-user about exploratory data analysis, the use of original data in an analysis, information and meaning in the context of digital image processing, and the role of visual interpretation, all of which serves to confirm the thought that has gone into IDRISI32. Particularly good and readable coverage is also given to topics like Fourier Analysis, Georeferencing, and Kriging. The idea of introducing a trick question is also carefully thought out. Clark Labs offer a range of UNITAR Workbooks (only two of the six are currently available for IDRISI32): Change and Time Series Analysis and Applications in Forestry. Online help is also provided through the detailed IDRISI32 Help System, through Technical Support and the Idrisi-L discussion list server. Additional support is provided by the 14 IDRISI Resource Centers around the World, and Clark Labs Educational Programs, and notably for schools by online Teacher Resources. 

Technical Support

Technical support is offered to users for:

• Software Installation
• Tutorial Exercise Assistance
• Software Operation
• Import and Export of Supported Data Formats
• Identification of Appropriate Module(s) for Particular Analyses

Ease of Installation

The IDRISI package was installed as per the instructions provided with the software in the Reference Guide using autorun and the setup program, and proved very straightforward. There were no problems installing the software on the machine chosen for this review. Although the Reference Guide details various requirements, no difficulties were experienced.

Ease of Use

Having not had the opportunity to use the IDRISI software for a little while, we have to say that we are very impressed by this current package of materials, the quality of the accompanying documentation, and the ease with which it is possible to simply get going. Perhaps more importantly, we like being able to see how you can use the software for various different applications; something that it is not always easy to do with all software. 

Starting the Software
Loading the software is the same as with any other Windows software package, and simply involves clicking on the desktop shortcut icon, or by access through the START, PROGRAMS menu.

Interface
The usability of software - which is largely determined by the interface, the manuals and tutorials, and the functionality for the end user (as well as the computer platform) is increasingly important for the busy GIS/Image Processing practitioner. The MSWindows-based interface presented to the IDRISI32 user is the usual combination of a menu bar and a series of drop-down menus, together with the usual buttonized icon bar populated with intuitive icons (Figure 4). To add clarity to the icons, positioning the mouse over each provides the user with the familiar text information balloon. The basic user-interface is simple to use and easy on the eye. Different options lead to sub-menus and/or pop-up windows and dialog boxes, all of which are likely to be fairly familiar to the average end-user. Some of the boxes include dialog windows, as well as buttons to, for example, locate and choose a file. For example, file location and access is simple and easy, as is file display and the use of the palettes.

Figure 4

IDRISI is a truly integrated GIS package that includes digital image processing software. On the whole, the IDRISI32 software is very impressive. It is an appealing and affordable piece of GIS “kit” that still has considerable scope for use in an educational/training environment, despite having evolved into a professional-level GIS. However, IDRISI32 must be evaluated on the basis of its ease of use, by means of notable features such as the Layer Properties, Project Environment, the Image Calculator, and the Symbol Workshop (Figures 5-7), its comprehensive breadth of functionality, excellent documentation, and the many avenues of support offered. 

Figure 5

Figure 6

But, it should also be mentioned that IDRISI is perhaps not for the faint-hearted, and, if anything, highlights the complexity of GIS as an analytical toolbox. This is something that is perhaps not clearly recognised by the layman who may have heard that GIS is useful in their work, but does not fully appreciate that GIS is a lot more than just a simple mapping tool! What IDRISI does succeed in showing the end-user though, through its comprehensive approach, is just how powerful and valuable a tool GIS can be for geospatial data exploration, analysis, and visualization to aid us in improving our knowledge and understanding of the real world. This is a highly functional toolbox with considerable application potential.

Disadvantages

There do not seem to be many real problems except for a few relatively minor things. However, to utilise a number of existing image datasets available to us did seemingly reveal a few potentially annoying problems. For example, the ERDAS Imagine format does not seem to be directly supported yet. However, an ArcView .SHP file (UK Census ward boundaries for the County of Surrey) went straight in with no problems (Figure 8), as did a GeoTIFF (a Landsat TM image of the Solway Firth, UK, originating in ERDAS Imagine (Figure 9)). The export to the .JPG format also worked without any problems. While the IDRISI package is not really any different than many other software packages on the data import/export front, so that all different data formats can be used effortlessly, it has to be said that most desktop software still needs to be able to handle a wide range of data formats more smoothly. Gone are the days where people are willing to experiment with getting the data into the system. Data really needs to go straight into a system with a minimum of effort for the current generation of users.

Reference to the IDRISI discussion list (IDRISI-L) also suggests that people experience similar types of problems when trying to work with their own data, but more often when trying to undertake analyses. These “online discussion lists” for IDRISI users offer a good form of practical support whereby it may perhaps help to identify possible ‘bugs’ in a software version release, or alternatively help someone to prepare and process their GIS and remotely-sensed data. They also probably help in the development of the software product in direct response to specific difficulties experienced by of the end-user due to their expectations. To be fair, this is a problem faced by many people with any current software, especially now with the rapid growth in the breadth of the end-user base and where both theoretical and practical expertise are sometimes limited. No software package, however good, will suit every potential user, nor will it be entirely free from little glitches, and unfortunately, accompanying tutorials and manuals can never cover all the possible tasks that people might want to use the software for. However, having said this, we do think that the IDRISI32 tutorial exercises and documentation provide a very good range of examples that can be used as templates for new applications, and evidence of the wide range of user support suggests that help is always at hand. 

Definitions
Some improvements to the definitions of eigenvalues and eigenvectors in Principal Components Analysis (PCA) would be helpful, and perhaps even a worked example could be included as this particular subject matter always seems to be rather hazy without a clear, concise and meaningful statement to help the user interpret the output.

Tutorial sheets
One helpful addition to the IDRISI manuals would be the inclusion of illustrations of the expected output. Another, might be the inclusion of some summarised tutorial worksheets that would help the tutor to use the software in classes. Whilst the background materials in the tutorial exercises are very helpful, a list of commands within the body of the text is sometimes a little difficult to follow even though it is acknowledged that the combined background, explanation and instructions held in one place is important. We know from many years of practical classes that students sometimes find such exercises difficult to complete in a short period of time. They may become quite disillusioned with software if they miss an essential step, only to find later on that a missing command requires them to repeat the work. However, there are few instances where this is now likely to happen. 

Recommendations

The fact that IDRISI is still with us after so many years (1986/7 – present) is sheer testimony, we think, to the quality and value of this software in the world of education, research, and practice. Given its affordable cost and the level of support, it offers a very attractive GIS/DIP software package for many people, but goes beyond many others in terms of its analytical functionality and ease of use. By comparison, to the first DOS version of IDRISI, the latest version of IDRISI for MS-Windows is a real revolution for the end-user. While retaining the positive points of earlier versions of IDRISI (both DOS and Windows), it has also taken full advantage of the Windows environment, and, we suspect, the feedback from the large end-user community over the years. The end result is a comprehensive geospatial data handling and analysis toolbox that is really quite unique in terms of what can be done with it. It is not perfect, but does score as far as the end-user is concerned in terms of its ease of use and the accompanying documentation and has a valuable role to play in GIS/DIP education, training, research, and project work.