ERDAS IMAGINE

ERDAS IMAGINE is a raster graphics editor and remote sensing application designed by ERDAS, Inc. The latest version is 9.3. It is aimed primarily at geospatial raster data processing and allows the user to prepare, display and enhance digital images for use in GIS or in CAD software. It is a toolbox allowing the user to perform numerous operations on an image and generate an answer to specific geographical questions.

By manipulating data placement in imagery it is possible to see features that would not normally be visible. The level of brightness, or reflectance of light from the surfaces in the image can be helpful with vegetation analysis, prospecting for minerals etc. Other usage examples include linear feature extraction, generation of processing chains ("spatial models" in ERDAS IMAGINE), import/export of data for a wide variety of formats, ortho-rectification, mosaicing of imagery, stereo and automatic feature extraction of map data from imagery.

Product history
Prior to the ERDAS IMAGINE Suite, ERDAS, Inc. developed various different products to process satellite imagery from AVHRR, Landsat MSS, Landsat TM and SPOT imagery into land cover / land use maps, map deforestation, and assist in locating oil reserves. These applications exist today within the ERDAS IMAGINE Suite which has grown to support most satellites, airborne mapping cameras and digital sensors used for mapping.

ERDAS 4
The first version of ERDAS was launched in 1978 on Cromemco microcomputers based on the 8-bit Z80 CPU running the CDOS operating system. The system was built into a desk and was configured with one color monitor (256 x 256 resolution), one B&W monitor, two 8" floppy drives (one for software and one for data). Later other options were added, such as a large digitizing tablet, and a hard drive (hard drives usually did not exist on computers this size). The hard drive was a CDC-Wren about the size of a small washing machine. It had 80 MB fixed disks and a very large 16 MB removable platter. When the hard disk was installed, ERDAS engineers had to take a cut out the back of the computer furniture to make room for the cables.

ERDAS 400
In 1980, ERDAS, Inc. developed the ERDAS 400. This early ERDAS system was a turnkey computerized forest-management system for the state of New York system. The hardware needed to make this capability available at an affordable price did not exist at the time, therefore some circuit board and other hardware designs were needed to deliver the product. Between 1980 and 1982 different versions of ERDAS 400 legacy were delivered to NASA, US Forest Service, US Environmental Protection Agency, the State of Illinois, and others.

ERDAS 7.x
In November 1982 ERDAS 7.0 was released. This product was a movement from the more turnkey, custom design of the ERDAS 400 systems to a MS DOS IBM PC. These systems continued to be a command prompt system, but added a nested menu assisting the customers through the prompted needed do process the imagery into data used in a GIS.

In ERDAS 7.2 (Jan 1983) the first PC version of ERDAS software was licensed to the University of South Carolina Department of Geography. The release of versions ERDAS 7.0 - 7.5 marked a period of wide acceptance of remote sensing technology among US federal and state agencies as well as research universities needing to monitor natural resource changes.

A link between ESRI ARC/INFO and ERDAS 7.3 was introduced in 1988. The "ERDAS-ARC/INFO Live Link" allowed the mapping community to use technology from both companies to deliver high quality image display and image processing with powerful GIS capability. This relationship between ESRI and ERDAS, Inc. at a high management level and in various products offerings into 2007.

ERDAS IMAGINE
ERDAS IMAGINE was demonstrated in October 1991 and released as ERDAS IMAGINE 8.0 in February 1992. It was released on a Sun Workstation using SunOS providing a Graphical User Interface to assist in visualizing imagery used in mapping, vector GIS data, creating maps, and so forth. Much of the ERDAS 7.5 product was provided for several years through intermediate product releases of ERDAS 8.01 & 8.02 until the ERDAS IMAGINE product replaced all the ERDAS 7.5 capability in 1994 with the release of ERDAS IMAGINE 8.1.

The relationship between the ERDAS and ARC/INFO products began with the "ERDAS-ARC/INFO Live Link" was expanded in ERDAS IMAGINE 8.2 (Feb 1993), when ERDAS released the IMAGINE Vector Module. This add-on was fully developed by ERDAS, but licensed the Arc coverage data format from ESRI. The vector module is one of the most popular modules within the ERDAS IMAGINE product suite through the 9.3 release (Sept 2008).

The processing of radar data in ERDAS IMAGINE began with the development of the Radar Module, released in Nov. 1992. The capabilities have been upgraded many times since with the original tools now named "Radar Interpreter."

ERDAS IMAGINE Spatial Modeler
With the release of ERDAS 7.5 in 1990 ERDAS introduced a GIS MOdeling (GISMO) script language. Tools were made available to assist in the development of complex spatial models using Dana Tomlin’s Map Algebra concepts. GISMO was upgraded in 1992 with the release of ERDAS IMAGINE 8.0 and the Spatial Modeler scripting language. Model Maker, a graphic flow chart model building enhancement to Spatial Modeler was introduced in 1993. In 2004 ESRI copied the graphic flow chart model building environment idea and released an ArcGIS version named Model Builder.

ERDAS IMAGINE Softcopy Photogrammetry
In Dec. 1991, "ERDAS Digital Ortho" was released in the mature ERDAS 7.5 product suite. Digital Ortho was one of the earliest commercial softcopy photogrammetry packages. It was upgraded to "IMAGINE Digital Ortho" in ERDAS IMAGINE 8.0.1 release. IMAGINE Digital Ortho was upgraded to the "IMAGINE OrthoMAX" in 8.0.2. The release of OrthoMAX was a move from a GIS and Remote Sensing user focus to a Photogrammetry user focus. This changed the IMAGINE photogrammetry offerings into more of a production realm, where the remote sensing products had moved years before. In version 8.3.1 (Jan 1998) OrthoMAX was upgraded into the OrthoBASE product. Along with the release of OrthoBASE single frame resection was added to the core IMAGINE product. This allowed the GIS community to ortho-correct imagery as needed on a non-production level.