System and method for synchronizing raster and vector map images Number:7,161,604 from the United States Patent and Trademark Office (PTO) owispatent A system and method for coordinated manipulation of multiple displayed maps, even when the maps use different internal coordinate systems. According to this embodiment, each map image to be displayed is first georeferenced, to provide a set of conversion functions between each map's internal coordinate system and a geographic coordinate system, which is latitude/longitude in the preferred embodiment. After this is done, any point on each map can be referenced using the geographic coordinate set. Since this is the case, the maps can now be manipulated, edited, and annotated in a synchronized manner, by defining the manipulations in terms of the geographic coordinate system, and using the georeferencing functions to translate the manipulation to each map's internal coordinate system.<H synchronizing, images, System, and, meth, 7161604.html, Patent, pto, 7161604

Title: System and method for synchronizing raster and vector map images

Abstract: A system and method for coordinated manipulation of multiple displayed maps, even when the maps use different internal coordinate systems. According to this embodiment, each map image to be displayed is first georeferenced, to provide a set of conversion functions between each map's internal coordinate system and a geographic coordinate system, which is latitude/longitude in the preferred embodiment. After this is done, any point on each map can be referenced using the geographic coordinate set. Since this is the case, the maps can now be manipulated, edited, and annotated in a synchronized manner, by defining the manipulations in terms of the geographic coordinate system, and using the georeferencing functions to translate the manipulation to each map's internal coordinate system.

Patent Number: 7,161,604 Issued on 01/09/2007 to Higgins, et al.

Inventors: Higgins; Darin Wayne (Fort Worth, TX), Scott; Dan Martin (Irving, TX)
Assignee: SourceProse Corporation (Euless, TX)

Appl. No.: 09/821,172

Filed: March 29, 2001

Current U.S. Class: 345/619

Current International Class: G09G 5/00 (20060101)

Field of Search: 345/427,569,665,667,682,629,619,7

References Cited [Referenced By]

U.S. Patent Documents


4254467	March 1981	Davis et al.
4458330	July 1984	Imsand et al.
4737916	April 1988	Ogawa et al.
4852183	July 1989	Abe et al.
4876651	October 1989	Dawson et al.
4885706	December 1989	Pate et al.
4899136	February 1990	Beard et al.
5018210	May 1991	Merryman et al.
5050222	September 1991	Lee
5113517	May 1992	Beard et al.
5233335	August 1993	Berwin
5247356	September 1993	Ciampa
5274752	December 1993	Kawazome
5323317	June 1994	Hampton et al.
5381338	January 1995	Wysocki et al.
5396582	March 1995	Kahkoska
5406342	April 1995	Jongsma
5414462	May 1995	Veatch
5418906	May 1995	Berger et al.
5422989	June 1995	Bell et al.
5428546	June 1995	Shah et al.
5467271	November 1995	Abel et al.
5487139	January 1996	Saylor et al.
5592375	January 1997	Salmon et al.
5594650	January 1997	Shah et al.
5596494	January 1997	Kuo
5608858	March 1997	Kurosu et al.
5623679	April 1997	Rivette et al.
5623681	April 1997	Rivette et al.
5631970	May 1997	Hsu
5638501	June 1997	Gough et al.
5640468	June 1997	Hsu
5659318	August 1997	Madsen et al.
5682525	October 1997	Bouve et al.
5699244	December 1997	Clark, Jr. et al.
5699255	December 1997	Ellis et al.
5715331	February 1998	Hollinger
5719949	February 1998	Koeln et al.
5734756	March 1998	Sherman et al.
5748777	May 1998	Katayama et al.
5748778	May 1998	Onoguchi
5757359	May 1998	Morimoto et al.
5771169	June 1998	Wendte
5815118	September 1998	Schipper
5842148	November 1998	Prendergast et al.
5848373	December 1998	DeLorme et al.
5857199	January 1999	Tamano et al.
5884216	March 1999	Shah et al.
5884219	March 1999	Curtwright et al.
5892909	April 1999	Grasso et al.
5902347	May 1999	Backman et al.
5904727	May 1999	Prabhakaran
5907630	May 1999	Naoi et al.
5929842	July 1999	Vertregt et al.
5929865	July 1999	Balz et al.
5930474	July 1999	Dunworth et al.
5937014	August 1999	Pelin et al.
5961572	October 1999	Craport et al.
5966135	October 1999	Roy et al.
5966469	October 1999	Moon et al.
5969723	October 1999	Schmidt
5969728	October 1999	Dye et al.
5974423	October 1999	Margolin
5978804	November 1999	Dietzman
5986697	November 1999	Cahill, III
5987136	November 1999	Schipper et al.
5987173	November 1999	Kohno et al.
5987380	November 1999	Backman et al.
5991780	November 1999	Rivette et al.
5995023	November 1999	Kreft
5999878	December 1999	Hanson et al.
6005509	December 1999	Buckreuss
6006161	December 1999	Katou
6008756	December 1999	Boerhave et al.
6032157	February 2000	Tamano et al.
6044324	March 2000	Boerhave et al.
6061618	May 2000	Hale et al.
6084989	July 2000	Eppler
6119069	September 2000	McCauley
6144920	November 2000	Mikame
6148260	November 2000	Musk et al.
6161105	December 2000	Keighan et al.
6202023	March 2001	Hancock et al.
6218965	April 2001	Gendron et al.
6236907	May 2001	Hauwiller et al.
6249742	June 2001	Friederich et al.
6307573	October 2001	Barros
6321158	November 2001	DeLorme et al.
6339745	January 2002	Novik
6377210	April 2002	Moore
6377278	April 2002	Curtright et al.
6462676	October 2002	Koizumi
6487305	November 2002	Kambe et al.
6489920	December 2002	Anders et al.
6504571	January 2003	Narayanaswami et al.
6505146	January 2003	Blackmer
6538674	March 2003	Shibata et al.
6549828	April 2003	Garrot et al.
6565610	May 2003	Wang et al.
6577714	June 2003	Darcie et al.
6606542	August 2003	Hauwiller et al.
6631326	October 2003	Howard et al.
6650998	November 2003	Rutledge et al.
6678615	January 2004	Howard et al.
6785619	August 2004	Homann et al.
2001/0026270	October 2001	Higgins et al.
2001/0028348	October 2001	Higgins et al.
2001/0033290	October 2001	Scott et al.
2001/0033291	October 2001	Scott et al.
2001/0033292	October 2001	Scott et al.
2002/0035432	March 2002	Kubica et al.
2002/0143469	October 2002	Alexander et al.
2002/0145617	October 2002	Kennard et al.
2002/0147613	October 2002	Kennard et al.
2003/0052896	March 2003	Higgins et al.
2005/0073532	April 2005	Scott et al.

Foreign Patent Documents


0 454 129	Oct., 1991	EP
0 619 554	Oct., 1994	EP
WO 90/14627	Nov., 1990	WO
WO 97/49027	Dec., 1997	WO

Other References

Li et al., "Accuracy Assessment of Mapping Products Produced from the Star-3i Airborne IFSAR System". cited by other .
Fukunaga et al., "Image Registration Using an Image Graph and its Application to Map Matching," IEE Proceedings-E, vol. 138, No. 2, Mar. 1991. cited by other .
Wang, "Integrating GIS's and Remote Sensing Image Analysis Systems by Unifying Knowledge Representation Schemes," IEEE Transactions on Geoscience and Remote Sensing, vol. 29, No. 4, p. 656-664, Jul. 1991. cit- ed by other .
WiseImage X Quick Start, Consistent Software, 2000-2005, p. 1-77. cited by other .
WiseImage X for Windows, IDEAL.com, 2000-2005, p. 1-2. cited by other .
Fekete, Jean-Daniel et al., "Using the Multi-layer Model for Building Interactive Graphical Applications," ACM, pp. 109-118, 1996. cited by oth- er .
Reddy et al., "Under the Hood of GeoVRML 1.0," Proceedings of the Fifth Symposium on Virtual Reality Modeling Language (Web3D-VRML), Feb. 2000. cited by other .
Burton et al, "Using High Performance GIS Software to Visualize Data: a Hands-On Software Demonstration," Proceedings of the 1998 ACM/IEEE Conference on Supercomputing (CDROM), Nov. 1998. cited by other .
G. Wiederhold, "The Role of Government in Standards," StandardView, Dec. 1993 vol. 1 Issue 2. cited by other .
P. Wilson, "The Application of Computer Graphics to Environmental Planning," Proceedings of the ACM 1980 Annual Conference, Jan. 1980. cite- d by other .
CDS Mapping Systems, et al., "CDS Business Mapping," Feb. 2, 1999. http://web.archive.org/web/19990202115053/www/cdsys.com/index.html. cited by other .
GeoPlace.com et al., "Mapping Awarenes," 1999 http://web.archive.org/web/20000301085059/www/geoplace.com/archives.asp. cited by other .
Jul. et al., "Critical Zones in Desert Fog: Aid to Multi-scale Navigation," Nov. 1998. cited by other .
Tan, et al., "Exploring 3D Navigation: Combining Speed-Coupled Flying with Orbiting," Mar. 2001. cited by other .
Radford, "The Use of GIS in Flood Hazard Analysis: A Report for the City of Warnick and Project Impact," Jun. 1999. cited by other .
"R2V: Advanced Raster to Conersion Software for Automated Map Digitizing," Able Software Corp., Sep. 20, 1999, pages 1-4. cited by other .
Jul, et al., "Critical Zones in Desert Fog: Aids to Multi-scale Navigation," Nov. 1998. cited by other .
Tan, et al., "Exploring 3D Navigation: Combining Speed-Coupled Flying with Orbiting," Mar. 2001. cited by other .
Mitchell, et al., "The NASA Digital Earth Testbed," Nov. 2000. cited by other .
Radford, "The Use of GIS in Flood Hazard Analysis: A Report for the City of Warnick and Project Impact," Jun. 1999. cited by other .
"R2V: Advanced Raster to Vector Conversion Software for Automated Map Digitalizing," Able Software Corp., Sep. 20, 1999, pages 1-4. cited by other.

Primary Examiner: Tung; Kee M.
Assistant Examiner: Amini; Javid
Attorney, Agent or Firm: Finnegan, Henderson, Farabow, Garrett, & Dunner, L.L.P.

Parent Case Text

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority from pending U.S. patent application "System and Method for Synchronizing Raster and Vector Map Images",(Ser. No. 09/537,162) filed Mar. 29, 2000. Furthermore, this application is related to and claims priority from the following pending applications: "System and Method for Performing Flood Zone Certifications" (Ser. No. 09/537,161) filed Mar. 29, 2000 and "System and Method for Georeferencing Digital Raster Maps" (Ser. No. 09/537,849) filed Mar. 29, 2000 which are hereby incorporated by reference.

Claims

What is claimed is:

1. A system for automatically annotating a second map when a first map is annotated, the second map being geographically substantially similar to the first map, the system comprising: a map display; a map processing platform in communication with the map display, whenever said map processing platform is adapted to: receive a user annotation at a first location on the first map expressed by first map coordinates; convert from the first map coordinates to corresponding geographic coordinates using a georeferencing function of the first map; convert from the geographic coordinates to corresponding second map coordinates using a georeferencing function of the second map; and display the user annotation on the second map at the second map coordinates; a storage platform coupled to the map processing platform; and a user interaction device coupled to the map processing platform.

2. They system of claim 1, wherein the map display is enabled to display a first map in a first area of the map display and to display a second map in a second area of the map display.

3. The system of claim 1 wherein the map display is coupled to a graphics adapter.

4. The system of claim 1 wherein the processing platform is a microprocessor.

5. The system of claim 1 wherein the map processing platform is an application service provider.

6. The system of claim 1 wherein the map processing platform is located remotely from the map display.

7. The system of claim 1 wherein the storage platform comprises cached memory.

8. The system of claim 1 wherein the storage platform comprises system memory.

9. The system of claim 1 wherein the storage platform comprises random access memory.

10. The system of claim 1 wherein the user interaction device comprises a mouse.

11. The system of claim 1 wherein the map processing platform and the map display are coupled via a network.

12. The system of claim 1 wherein the network is the internet.

13. The system of claim 1 wherein the storage platform is associated with the map processing platform via a network.

14. The system of claim 13 wherein the network is the internet.

15. The system of claim 1 wherein the storage platform maintains code that enables the automatic manipulation of the second map when the first map is manipulated by: determining a boundary of a geographic region of the first map; converting the boundary of the geographic region of the first map into a corresponding boundary of the second map; and configuring the boundary of the second map for display.

16. A method for annotating a second map when a first map is annotated, the second map being geographically substantially similar to the first map, the method comprising; detecting an annotation entry on the first map expressed by first map coordinates; converting from the first map coordinates to corresponding geographic coordinates using a georeferencing function of the first map; converting from the geographic coordinates to corresponding second map coordinates using a georeferencing function of the second map; and displaying the annotation entry on the second map at the second map coordinates.

17. A computer readable medium containing instructions executable by a computer to perform a method for annotating a second map when a first map is annotated, the second map being geographically substantially similar to the first map, the method comprising: detecting an annotation entry on the first map expressed by first map coordinates; converting from the first map coordinates corresponding geographic coordinates using a georeferencing function of the first map; converting from the geographic coordinates to corresponding second map coordinates using a georeferencing function of the second map; and displaying the annotation entry on the second map at the second map coordinates.

18. The system of claim 1, wherein the map processing platform is adapted to: receive a user manipulation of the first map; and implement the user manipulation on the second map.

19. A method for automatically annotating a second map when a first map is annotated, the second map being geographically substantially similar to the first map, the method comprising: receiving an annotation on the first map; determining a location of the annotation on the first map using a coordinate system of the first map; converting the location to longitude and latitude using a georeferencing function of the first map; determining a corresponding location on the second map based on the longitude and latitude using a georeferencing function of the second map; and displaying the annotation on the second map at the corresponding location.

Description

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention generally relates to graphic image manipulations and in particular to manipulation of map images. Still more particularly, the present invention relates to the coordinating the manipulation of multiple map images displayed on a data processing system.

2. Description of the Related Art

Modern geographic information systems normally make use of digital vector-based map information. However, a vast legacy of paper-based map information exists. It is very expensive and time consuming to convert all of the information on these paper maps over to a digital vector format. In many cases the scope and expense of such conversions renders them completely impractical. However, even when a complete conversion to digital vector-based format is not possible, it is still possible to obtain some of the benefits of computerized map systems, first by converting the paper maps to digital raster maps by digitally scanning them, and then by georeferencing the raster image.

A digital map image is said to be georeferenced if a pair of mathematical functions, f, and g, have been determined that can be used to convert back and forth between the coordinates of the map image (as defined by the pixels of the image) and the corresponding longitude and latitude of the location of that point. That is, f and g do the following:

1. If (x, y) represents a location on the digital map image, then f (x, y)=(Lon, Lat) represents the longitude and latitude of the corresponding physical location.

2. If (Lon, Lat) represents a physical location that lies within the region covered by the map, then g(Lon, Lat)=(x, y) represents the point on the digital map image that corresponds to that longitude and latitude.

Here, x and y represent the natural internal coordinate system of the map image. In most cases, a vector-based map image uses longitude and latitude as its internal coordinate system, if so, it can be considered to be trivially georeferenced already.

Typically a digital raster map image uses the pixels of its image as a kind of natural coordinate matrix. This type raster map image will require non-trivial georeferencing functions to convert back and forth between coordinate systems.

In a geographic information system, both raster maps and vector maps are often used, since raster maps can be easily obtained from the vast wealth of paper maps available, and vector maps can contain a great amount of underlying data. When each of these maps are displayed, users will typically desire to manipulate the view, by scrolling, zooming, or otherwise. If more than one map is being displayed, the user is typically required to independently manipulate each map to the desired view. It would be desirable to provide a means for a user to simultaneously manipulate both maps, even when the maps use different internal coordinate systems.

SUMMARY OF THE INVENTION

It is therefore one object of the present invention to provide improved graphic image manipulations.

It is another object of the present invention to provide improved manipulation of map images.

It is yet another object of the present invention to provide an improved system and method for coordinating the manipulation of multiple map images displayed on a data processing system.

The foregoing objects are achieved as is now described. The preferred embodiment provides a system and method for coordinated manipulation of multiple displayed maps, even when the maps use different internal coordinate systems. According to this embodiment, each map image to be displayed is first georeferenced, to provide a set of conversion functions between each map's internal coordinate system and a geographic coordinate system, which is latitude/longitude in the preferred embodiment. After this is done, any point on each map can be referenced using the geographic coordinate set. Since this is the case, the maps can now be manipulated, edited, and annotated in a synchronized manner, by defining the manipulations in terms of the geographic coordinate system, and using the georeferencing functions to translate the manipulation to each map's internal coordinate system.

The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following detailed written description.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

FIG. 1 depicts a data processing system in accordance with a preferred embodiment of the present invention;

FIG. 2 is an exemplary raster map, in accordance with the preferred embodiment;

FIG. 3 is an exemplary vector map, corresponding to the raster map of FIG. 2, in accordance with a preferred embodiment of the present invention;

FIG. 4 is a flowchart of a process in accordance with a preferred embodiment of the present invention; and

FIG. 5 shows a flowchart of a map annotation process

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference now to the figures, and in particular with reference to FIG. 1, a block diagram of a data processing system in which a preferred embodiment of the present invention may be implemented is depicted. Data processing system 100 includes processor 102 and associated L2 Cache 104, which in the exemplary embodiment is connected in turn to a system bus 106. System memory 108 is connected to system bus 106, and may be read from and written to by processor 102.

Also connected to system bus 106 is I/O bus bridge 110. In the exemplary embodiment, data processing system 100 includes graphics adapter 118 connected to bus 106, receiving user interface information for display 120. Peripheral devices such as nonvolatile storage 114, which may be a hard disk drive, and keyboard/pointing device 116, which may include a conventional mouse, a trackball, or the like, are connected to I/O bus 112.

The exemplary embodiment shown in FIG. 1 is provided solely for the purposes of explaining the invention and those skilled in the art will recognize that numerous variations are possible, both in form and function. For instance, data processing system 100 might also include a compact disk read only memory (CD-ROM) or digital video disk (DVD) drive, a sound card and audio speakers, and numerous other optional components. All such variations are believed to be within the spirit and scope of the present invention. Data processing system 100 is provided solely as an example for the purposes of explanation and is not intended to imply architectural limitations.

The preferred embodiment provides a system and method for coordinated manipulation of multiple displayed maps, even when the maps use different internal coordinate systems. According to this embodiment, each map image to be displayed is first georeferenced, to provide a set of conversion functions between each map's internal coordinate system and a geographic coordinate system, which is latitude/longitude in the preferred embodiment. After this is done, any point on each map can be referenced using the geographic coordinate set. Since this is the case, the maps can now be manipulated, edited, and annotated in a synchronized manner, by defining the manipulations in terms of the geographic coordinate system, and using the georeferencing functions to translate the manipulation to each map's internal coordinate system. Once this has been done, it becomes possible to effectively display the information on a raster map in synchronization with information contained on other raster maps or on ordinary vector-based maps.

The preferred embodiment may be applied to any system which simultaneously displays multiple map images, but is particularly valuable for systems displaying a raster map image and a vector map image.

Map image synchronization is a method whereby two map images can be made to show the same geographic region at all times, maintaining this synchronization even after one of the images is panned, zoomed scrolled, or otherwise caused to display a different region. Whenever such a change occurs on one map, the system causes the same change to occur on the other map as well. In this way, the two images continue to display the same region, without the need of manually adjusting both maps. In addition the synchronization system allows annotations to be placed on either map at specified geographic locations, and causes a matching annotation to appear on the other map in the corresponding location.

The two maps in question may be any combination of digital raster and vector-based maps, as long as georeferencing information is available for both maps. According to the preferred embodiment, one map is a digital raster map, and the other map is a vector map, both maps covering the same geographic area. Multiple configurations of the map display are possible. These include:

1. Both maps are displayed side by side, or one above the other on the computer display.

2. One map is superimposed directly on top of the other. a. The background of the top map is transparent, so that the user can see features of both the top map and the bottom map. b. Both maps are opaque, but a user may toggle back and forth rapidly between the two images.

FIG. 2 is an exemplary raster map, in accordance with the preferred embodiment. This exemplary map shows a scanned image from a Federal Emergency Management Agency (FEMA) paper map. This raster image shows land area with flood zone indications, but would, in a computer system, contain no underlying data regarding the area shown.

FIG. 3 is an exemplary vector map, corresponding to the raster map of FIG. 2, in accordance with a preferred embodiment of the present invention. This map shows the same area as the map in FIG. 2, but is created by a computer system from a database describing the locations of features such as the streets shown. Typically, each feature shown on a vector map such as this will already be georeferenced, in that the geographic coordinates of each feature will also be recorded in the underlying data.

The process of the preferred embodiment, as shown in the flowcharts of FIGS. 4 and 5, operates in the following way:

FIG. 4 shows a map manipulation process in accordance with the preferred embodiment. First, the data processing system loads and displays two maps, Map1 and Map2, according to a user selection (step 400). For purposes of this example, assume that Map1 is a digital raster map, and Map2 is a vector map showing substantially the same region. It should be noted that the maps displayed are not required to cover identical geographic regions, as long as they share some geographic area in common. Both maps, according o the preferred embodiment, are previously georeferenced. In an alternate embodiment, the system will allow the user to georeference one or both maps, if required.

Next, an initial geographic region, which is present on both maps, is--selected on Map 1 and displayed by the system (step 405). Since Map1 has been georeferenced, the boundaries of the selected region are determined, using Map1's set of georeferencing functions, in terms of longitude and latitude (step 410).

The system then converts these boundaries, using the georeferencing function set of Map2, between the latitude/longitude boundaries of the display region and the internal coordinate system of Map2 (step 415). Next, the system displays the same region of Map2 (step 420), according to the same geographic boundaries.

Thereafter, as the user interacts with the system by causing one of the maps, Map1 in this example, to display a different geographic region or view (step 425), the system performs the following steps. Note that this manipulation by the user can include any change in the map view, including but not limited to scrolling, zooming, rotating, or changing the view perspective of the map, and that the user can be performing the manipulation on either map.

The system first determines the boundaries of the newly displayed region of Map1 in the natural coordinate system of Map1 (step 430). Next, the system uses the georeferencing function set of Map1 to convert the boundaries to be in terms of longitude and latitude (step 435).

The system then uses the georeferencing functions of Map2 to determine the boundaries of the new region in terms of the natural coordinate system of Map2 (step 440). The system then performs the appropriate image scaling and manipulation functions, known to those of skill in the art, to redraw Map2 with the same boundaries, and according to the same changes in scale and perspective, as Map1 (step 445) The user may then stop his manipulation and view the maps, continue to manipulate the maps, or annotate the map (step 450). Note that the steps above are performed rapidly enough, in the preferred embodiment, that it appears that the user is manipulating both maps in synchronicity.

FIG. 5 shows a flowchart of a map annotation process in accordance with the preferred embodiment. When the user places an annotation on one of the maps (step 500), Map1 in this example, then the system performs the following steps. First, the system determines the location of the new annotation of Map1 in the natural coordinate system of Map1 (step 505). Next, the system uses the georeferencing function set of Mapl to convert the annotation location to longitude and latitude (step 510). The system then uses the georeferencing function set of Map2 to express the annotation location to be in terms of the internal coordinate system of Map2 (step 520). Finally, the system displays the new annotation on Map2, in the location corresponding to the annotation on Map1 (step 525). The user may then stop his manipulation and view the maps, continue to manipulate the maps, or annotate the map (step 530). Again, the steps above are performed rapidly enough, in the preferred embodiment, that it appears that the user is annotating both maps in synchronicity.

Common changes, that might occur to change the region displayed include the user panning, zooming, or scrolling one of the images. Annotations may be used to designate points of particular interest on the maps.

Certain minor adjustments are required in the display if a region is selected which is not entirely present on one or more of the maps, or if the aspect ratios of the screen display areas devoted to each map are different. In the first case, the system attempts a "best fit" when one map selection included area not found in the other map, and simply displays blank additional area to fill the missing region, so that the map windows will be filled and the synchronization of the images maintained. In the second case, the other map can be scaled to reflect the same area, or alternatively one or more of the map windows may be equipped with scroll bars, so that the effective dimensions of the map windows become identical.

A specific example, which illustrates the utility of map synchronization, arises from the "Flood Zone Determination" business, The Federal Emergency Management Agency (FEMA). FEMA publishes a library of tens of thousands of paper maps showing various types of flood zones and their locations in the United States. When performing a flood zone certification, a map analyst must locate a property on a flood map and determine the type of flood zone that the property is contained in. Unfortunately, these FEMA maps frequently display only a subset of geographic landmarks (such as streets). This often forces a map analyst to refer to a separate street map to find the property, and, once found, to determine the corresponding location on the flood map. Map synchronization greatly facilitates this process. For example, with both the flood map and the street map displayed side by side, the map analyst might 1. Locate the property on the street map, including performing whatever map manipulations are necessary to show the required area, having the flood map be manipulated by the system to reflect that same area; 2. Place an annotation on the street map at the location of the property wherein the system places an identical annotation at the corresponding point on the flood map; and 3. Observe the location of the synchronously placed annotation on the flood map, and make the required flood zone determination.

In this way, the map synchronization system has reduced the difficulty and time involved in making this determination by a great margin.

It is important to note that while the present invention has been described in the context of a filly functional data processing system and/or network, those skilled in the art will appreciate that the mechanism of the present invention is capable of being distributed in the form of a computer usable medium of instructions in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of computer usable mediums include: nonvolatile, hard-coded type mediums such as read only memories (ROMs) or erasable, electrically programmable read only memories (EEPROMs), recordable type mediums such as floppy disks, hard disk drives and CD-ROMs, and transmission type mediums such as digital and analog communication links.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

*