FUE2/51

EBBA GIS IMAGE PROCESSING SYSTEM - SYSTEM DESCRIPTION

October 6, 1986

1. GENERAL

The EBBA GIS Image Processing System is a desk-top system for the analysis and processing of images in digital form. It is a new generation of system based on state-of-the-art technology. The system combines the power of the EBBA special-purpose image processor with the flexibility and convenience of the enormously successful IBM AT personal computer.

It is now feasible to process and display any type of digital image data in an office environment, and within a reasonable budget.

The architecture of the EBBA Image Processing System makes it highly suitable in a wide range of image processing applications. The EBBA system supports the digitization of images such as photographs and maps, so that any type of image may be analyzed. The versatility of the IBM/PC/AT personal computer opens the door to the integrated analysis of image data with other types of data. For instance, cartographic and remote sensing data can be analyzed in the same environment.

The EBBA Image Processing System is well equipped with powerful software packages, ranging from general purpose image processing to highly sophisticated remote sensing applications.

Swedish Space Corporation is a pioneer in the development and use of digital image processing systems in remote sensing. The system design reflects the many years of experience SSC has as a user of image processing systems.

2. SYSTEM CONFIGURATION

The basic EBBA GIS Image Processing System consists of an EBBA GIS Image Processor (including a trackball) in combination with an IBM PC/AT personal computer and a color monitor.

The basic system may be expanded into a complete application work station by adding one or more of the following peripherals as I/O (input/output) devices:

• a standard 9-track tape recorder;
• a digitizing tablet;
• a color matrix printer/plotter;
• a video camera.

3. THE EBBA GIS IMAGE PROCESSOR

The EBBA GIS Image Processor is the heart of the system. It consists of a set of image memory planes plus the processing power needed to perform various operations on the image data. In addition, it contains all the facilities needed to communicate with the host computer and peripheral devices.

The EBBA GIS Image Processor architecture is shown in figure 2 [not included]. The unit is equipped with three image memory planes. Each memory plane is capable of storing 1024x1024 pixels (picture elements), each pixel having a range of 256 grey levels (i e each pixel is represented by 8 bits). In total, the EBBA GIS Image Processor supports more than 32 Mbit of display memory.

With this large amount of memory, the operator can work with three different images or, alternatively, with one composite color image made up of a red, a green, and a blue image. The operator has immediate access to data for display and manipulation in the image memories. The result of each action is presented on the color monitor.

Each image memory has a function memory (FM) which controls the contrast and intensity of the image as presented on the color monitor. The operator is able to manipulate the intensity of the image being displayed interactively by using the trackball. For example, if a source image is very dark (i e most of the pixel values are in the low range of intensity) , the operator can adjust intensity until he gets a clear image, rich in contrast, on the color display. The original data in the image memories will not be altered by manipulating the function memories.

Function memory settings may be stored on the host computer just like any other data file.

The EBBA GIS Image Processor is also furnished with a pseudo-color memory. Using the pseudo-color memory, the operator can assign an arbitrary color to each grey level in a black-and-white image. The color palette contains more than 16 million colors! The color setting is easy and truly interactive.

The pseudo-color tool is very useful to enhance interpretation of a black-and-white image. For instance, an image resulting from a multispectral classification can be presented as a color image through the use of pseudo-color.

Pseudo-color memory settings may be stored on the host computer just like function memory settings.

The EBBA GIS Image Processor is also equipped with a fourth 1024x1024 pixel plane. This plane is subdivided into eight 1024x1024 one-bit graphic overlays (graphic memories) . A specific color is assigned to each overlay. The overlays can be used as masks over images, for performing logical operations, for presenting statistical histograms, and for writing text into an image.

Furthermore, there are 8 screen oriented graphic planes, 512x512 one-bit, for cursor, windows and miscellaneous data.

A powerful feature of the EBBA GIS Image Processor is the availability of transparent overlays. Each of the eight graphic overlays may be set to define different areas in an image. In each of these areas, the operator may then work with independent function and pseudocolor memories. This is most convenient when image data from different sources, or different types of image data, are to be presented together on the color screen.

As the EBBA GIS Image processor has a 512-display, it is possible either to show one quarter of the stored 1024x1024 image, or roam with a 512 window in the 1024 image.

4. SOFTWARE OVERVIEW

The EBBA GIS Image Processing System is supplied with a comprehensive package of image processing software. Much of the power of the system derives from the fact that the software has been implemented at different levels, combining the raw processing power of assembler level programs residing in the EBBA GIS Image Processor with the flexibility of high-level programs on the host computer.

Those programs which are resident in the EBBA GIS Image Processor have been implemented in down-load modules. This allows an analyst to perform all interactive functions at high speed, such as image manipulations and visual inspection, image enhancement, pseudo-color processing, drawing in graphics planes, and writing text on the color screen.

More complex functions, such as multispectral classification, spatial analysis, and vector data processing are performed in the host computer. An extensive library of remote sensing applications software is available. In addition, a user may develop his own customized software routines, drawing on those tools and routines which are already available.

5. POWERFUL LOW-LEVEL COMMANDS

The EBBA GIS Image Processor provides the analyst with over 70 powerful commands. These commands may be typed directly on the host computer keybord in a logical and easy-to-remember format, or they may be accessed by software in the host computer through a simple "toolbox" interface. This enables the user to use the EBBA commands as building blocks in creating higher level programs.

The list of available commands includes functions to manipulate and display image data, function memories, pseudo-color memories, and graphics data. Different display modes such as 512 mode, color, pseudo-color and roam may be selected. Simple arithmetic combinations of image data may be performed. Data may be transferred between image and graphics planes. Nearest-neighbor zoom (enlargement) may be performed. Logical operations between graphic overlays and image planes are available. Areas can be drawn interactively in the graphics planes and used in the classification of image data. Text may be written and erased in the graphics planes interactively. Statistical data may be calculated and displayed. Different cursor and digitizer functions are also available.

6. COMPREHENSIVE SOFTWARE PACKAGE

Applications software in high-level language is available at three levels:

The EBBA GIS Image Processor commands are accessible through a "toolbox" written in Pascal. This means that all the EBBA GIS commands are available to the programmer, as well as a set of basic DMA (direct memory access) routines.

The next level contains I/O (input/output) routines and many useful image processing routines. For instance, routines are available to move image data between the EBBA GIS Image Processor and the IBM/PC/AT Winchester and "floppy" disks. An interactive box classifier is provided. Routines are provided to calculate the area and perimeter of closed regions and to draw the borders of closed regions. Closed regions may also be expanded or shrunk. More complex arithmetical combinations of image planes are available. A cleanup filter is provided to remove isolated pixels in a classified image. An on-line "help" facility is provided. Additional routines are added to support peripheral devices (digitizing tablet, tape recorder, plotter/printer).

At the final level, the powerful EASI/PACE applications package developed by Perceptron Computing Inc (PCI) in Toronto, Canada, is provided. EASI/PACE is a comprehensive software package representing many man-years of development effort. EASI/PACE is marketed by Swedish Space Corporation under license.

EASI (Engineering Analysis and Scientific Interface) is a flexible and easily learned user interface. It enables the user to quickly become productive, as he only needs to learn one interface environment for the wide range of application programs available.

PACE (Picture Analysis, Correction and Enhancement) is a suite of application programs specifically written for remote sensing. It consists of over 60 functions, including radiometric corrections and enhancement, classification, spatial filtering, geometric correction, statistical and analytic reporting and plotting, frequency and spectral transforms, as well as a display control system for the EBBA.

The EASI/PACE package is based on the UNIDSK image data base developed by the Canada Centre for Remote Sensing (CCRS).

EASI/PACE is itself available in three versions:

a) A simple entry-level system, EASI/IQL (Image Quick-Look) ;

b) The EASI/PACE turnkey system;

c) The EASI/PACE programmable system.

7. WIDE RANGE OF PERIPHERALS

To take full advantage of the power of the EBBA GIS image Processing System, the following peripheral devices are provided in addition to the EBBA GIS Image Processor and the IBM/PC/AT.

The EBBA High Resolution Color Monitor

A 19-inch high-resolution color monitor displays the image and graphics data. The monitor is connected to the EBBA GIS Image Processor via a standard CCIR 625 lines, 50 Hz RGB-interface.

The EBBA Trackball

A trackball provides the operator with interactive control of cursor movement, function memory setting, pseudo-color setting, drawing in the graphics planes etc.

The EBBA Tape Drive

A 9-track, 1600 bpi industry-standard tape drive will, when connected to the EBBA system, provide high-speed I/O of image data. The tape drive interface is a standard 2 x 50 lines formatter compatible interface.

The EBBA Digitizing Tablet

A digitizing tablet is used to enter map data into the system. The tablet can also be programmed to have the same cursor control functions as the trackball. The digitizing tablet is connected to the EBBA GIS Image Processor via an RS-232 serial interface.

The EBBA Color Graphics Copier

A Tektronix 4695 Color Graphics Copier enables the user to transfer an intermediate or the end result from an image analysis session to hardcopy. The copier is connected to the EBBA system via an IBM/PC/AT parallel port interface.

The EBBA Video Camera

A video camera can be connected to the EBBA GIS image Processor via a standard CCIR interface. The camera may be used to input image data to the system. By using a set of color filters, an image may be color separated and transferred to the three image memories. A composite color image may then be generated on the color monitor.

The "frame grabbing" of an image is immediate and introduces no waiting time for the operator.

8. BRINGING IMAGE PROCESSING INTO THE OFFICE

The EBBA GIS Image Processing System puts the power of modern micro-computer technology at the finger tips of the applications specialist in his/her own office. The traditional picture of digital image processing as an expensive and complex activity, requiring special computing facilities and personnel is no longer valid.

Systems like EBBA mark the beginning of a new era, when applications specialists in many fields use micro computer systems as routine tools to process and analyze information according to their own needs. Just as most people find it perfectly natural to drive their cars without worrying about the detailed operation of the internal combustion engine, it now seems quite natural to use the micro computer as an everyday tool in many applications. The EBBA GIS image Processing System is already supporting geoscientists, forest managers, geologists, urban planners, environmental managers, and other professionals in their daily work.

Because the application specialist desires system support, SSC's commitment does not stop at delivery of the EBBA GIS Image Processing System. A full range of training and support services are offered according to the customer's needs. Technical service and software maintenance are provided. SSC has a long term commitment to image processing, systems and applications. At SSC, we believe that satisfied customers are the best ticket to the future!