The Microsoft TerraServer™
`
`Tom Barclay, Robert Eberl,
`Jim Gray, John Nordlinger, Guru Raghavendran,
`Don Slutz, Greg Smith, Phil Smoot
`Microsoft Research and Development
`
`John Hoffman, Natt Robb III,
`Aerial Images
`
`Hedy Rossmeissl, Beth Duff, George Lee, Theresa Mathesmier, Randall Sunne
`United States Geological Survey
`
`Lee Ann Stivers, Ken Goodman
`Digital Equipment Corporation
`
`June 1998
`
`Technical Report
`MSR-TR-98-17
`
`Microsoft Research
`Microsoft Corporation
`One Microsoft Way
`Redmond, WA 98052
`
`cs.DB/9809005 2 Sep 1998
`
`Microsoft Corp. Exhibit 1034
`
`

`

`Microsoft TerraServer™
`
`Tom Barclay, Robert Eberl,
`Jim Gray, John Nordlinger, Guru Raghavendran,
`Don Slutz, Greg Smith, Phil Smoot
`Microsoft Research and Development
`
`John Hoffman, Natt Robb III,
`Aerial Images
`
`Hedy Rossmeissl, Beth Duff, George Lee,
`Theresa Mathesmier, Randall Sunne
`United States Geological Survey
`
`Lee Ann Stivers, Ken Goodman
`Compaq Corporation
`
`June 1998
`
`Abstract
`The Microsoft TerraServer stores aerial and satellite images of the earth in a SQL Server Database
`served to the public via the Internet. It is the world’s largest atlas, combining five terabytes of
`image data from the United States Geodetic Survey, Sovinformsputnik, and Encarta Virtual
`Globe™. Internet browsers provide intuitive spatial and gazetteer interfaces to the data. The
`TerraServer demonstrates the scalability of Microsoft's Windows NT Server and SQL Server
`running on Compaq AlphaServer 8400 and StorageWorks™ hardware. The TerraServer is also an
`E-Commerce application. Users can buy the right to use the imagery using Microsoft Site Servers
`managed by the USGS and Aerial Images. This paper describes the TerraServer's design and
`implementation.
`
`The Microsoft TerraServer
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`Table of Contents
`The Microsoft TerraServer™ ................................................................................. 1
`The Application..........................................................................................................................1
`User Interface to the Microsoft TerraServer...............................................................................4
`Server Design .............................................................................................................................6
`Database Design ...................................................................................................... 9
`Coordinate Systems ....................................................................................................................9
`Image Format ...........................................................................................................................11
`Database Themes......................................................................................................................13
`Logical Database Design for Image Data .................................................................................15
`Database Design for Gazetteer .................................................................................................17
`Physical database design ..........................................................................................................20
`Data Loading ............................................................................................................................21
`Backup & Restore ....................................................................................................................23
`Microsoft TerraServer Hardware ......................................................................... 25
`Assessment............................................................................................................. 27
`Other Scalability Projects...................................................................................... 28
`Summary................................................................................................................ 29
`Acknowledgments.................................................................................................. 30
`References.............................................................................................................. 32
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`The Microsoft TerraServer
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`The Microsoft TerraServer™
`
`The TerraServer has five terabytes of satellite and aerial images of urban areas compressed to one
`terabyte of database data. It serves these images onto the Internet with a graphical and intuitive
`user interface. The application demonstrates several things:
`•
`Information at your fingertips: This is the most comprehensive world atlas anywhere — and
`it is available to anyone with access to the Internet.
`• Windows NT Server and SQL Server can scale up to huge nodes: The TerraServer fills
`eight large cabinets: one for the Compaq Alpha 8400 processors, and seven cabinets for the
`324 disks -- almost three terabytes of raw disk storage and 2.3 TB of RAID5 storage.
`• Windows NT and SQL Server are excellent for serving multi-media and spatial data onto
`the Internet.
`• Microsoft Site Server can help sell images over the Internet.
`
`TerraServer is a multi-media database that stores both
`classical text and numeric data, as well as multi-media
`image data. In the future, most huge databases will be
`comprised primarily of document and image data. The
`relational meta-data is a relatively small part of the total
`database size. TerraServer is a good example of this new
`breed of multi-media databases.
`
`The TerraServer hardware
`
`The Application
`An Interesting Internet Server: TerraServer is designed to be compelling Internet application. It
`tries to be interesting to almost everyone everywhere, be offensive to no one, and be relatively
`inexpensive to build and operate. It is hard to find data like that — especially a terabyte of such
`data. A terabyte is nearly a billion pages of text — 4 million books. A terabyte holds 250 full-
`length movies. It is a lot of data.
`
`Satellite Images of the Urban World: Pictures are big and have a universal appeal, so it was
`natural to pick a graphical application. Aerial images of the urban world seemed to be a good
`application. The earth's surface is about 500 square tera-meters. 75% is water, 20% of the
`rest is above 70(cid:176) latitude. This leaves about 100 square tera-meters. Most of that is desert,
`mountains, or farmland. Less than 4% of the land is urban. The TerraServer primarily stores
`images of urban areas. Right now, it has nearly five square tera-meters -- and it grows as
`more data becomes available.
`
`World population density
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`Cooperating with United States Geological Survey: The USGS has published aerial imagery of
`many parts of the United States. These images are approximately one-meter resolution
`(each pixel covers one square meter.) We have a Cooperative Research Agreement
`(CRADA) with the USGS to make this data available to the public. We have loaded all
`the published USGS data (3 TB raw, 0.6 TB compressed). This is 30% of the United
`States. As additional data becomes available, it will be loaded into the TerraServer. This
`data is unencumbered and can be freely distributed to anyone. It is a wonderful resource
`for researchers, urban planners, and students. The picture at left shows a baseball game in
`progress near San Francisco. You can see the cars, but one-meter resolution is too coarse
`to show people.
`
`A USGS 1-meter resolution
`image of Candlestick Park near
`San Francisco
`
`Working with Sovinformsputnik (the Russian Space Agency) and Aerial Images. To
`be interesting to everyone everywhere, TerraServer must have worldwide coverage. The
`USGS data covers much of the continental United States. There is considerable imagery
`of the planet, but much of it either has poor quality (10 meter to 1-km resolution), or has
`not been digitized, or is encumbered. Sovinformsputnik and their representative Aerial Images
`have some of the best data and were eager to cooperate. The Russians and Aerial Images
`contributed two square tera-meters of imagery (1.56-meter resolution). This data is trademarked
`SPIN-2, meaning satellite-2-meter imagery. They intend to deliver an additional 2.4 square
`terra-meters over the next year.
`
`TerraServer is the largest world atlas: The Sovinformsputnik SPIN-2 imagery covers
`Rome, Athens, Hong Kong, New York, Chicago, Seattle, and many other cities.
`TerraServer has more data in it than ALL the HTML pages on the Internet. If printed in a
`paper atlas, with 500 pages per volume, it would be a collection of 2,000 volumes. It
`grows by 10,000 pages per month. Clearly, this atlas must be stored online. The USGS
`data (the three square tera-meters) is seven times larger. This data is a world-asset that will
`likely change the way geography is taught in schools, the way maps are published, and the
`way we think about our planet.
`
`A SPIN-2 1.6-meter image of
`Atlanta’s Olympic stadium.
`
`TerraServer as a business. Slicing, dicing, and loading the SPIN-2 and USGS data is a
`continuing process. Today, the TerraServer stores a terabyte. Aerial Images, Compaq, and
`Microsoft are operating the TerraServer on the Internet (www.microsoft.com/
`TerraServer). Microsoft views TerraServer as a demonstration for the scalability of Windows NT
`Server and Microsoft SQL Server. Compaq views it as a demonstration for their Alpha and
`StorageWorks servers. The USGS is participating as an experiment on presenting USGS data to a
`wider audience through the Internet. They operate an online store that allows anyone to download
`copies of the USGS images. Sovinformsputnik and Aerial Images view TerraServer as a try-and-
`buy distributor for their intellectual property. They make coarse-resolution (8-meter, 16-meter, and
`32-meter) imagery freely available. The fine-resolution data is viewable in small quantities, but
`customers must buy the right to use the "good" imagery. All the SPIN-2 images are watermarked,
`and the high-resolution images are lightly encrypted.
`
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`Site Server, a new business model for the Internet. Aerial Images’ business model is likely to
`become a textbook case of Internet commerce. By using the Internet to sample and distribute their
`images, Aerial Images has very low distribution costs. This allows them to sell imagery in small
`quantities and large volumes. Microsoft helped USGS and Aerial Images set up Microsoft Site
`Servers that accept credit-card payments for the imagery. A "download" button on the image page
`takes the user to these Site Servers (Microsoft has no financial interest in these transactions). You
`can buy a detailed image of your neighborhood for a few dollars.
`
`Navigation can be via name
`(left) or via a map (right).
`In either case, the user can
`select the USGS or SPIN-2
`images for the place
`
`The coverage map at left shows
`green where the TerraServer has
`imagery. By clicking on the
`coverage map, users can quickly
`zoom on a particular spot.
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`User Interface to the Microsoft TerraServer
`
`Navigation via database searches: The TerraServer can be accessed from any web browser (e.g.
`Internet Explorer, Netscape Navigator). Full resolution SPIN-2 imagery requires the web browser
`to support Java™ applets. Any web browser that supports HTML tables and display of Jpeg data
`can host the TerraServer user interface. Navigation can be a spatial via a point-and-click map
`control based on Microsoft's Encarta® World Atlas. Clients only knowing the place name can
`navigate textually by presenting a name to the Encarta Virtual Globe Gazetteer. The gazetteer
`knows the names and locations of 1.1 million places in the world. For example, "Moscow" finds 28
`cities, while "North Pole" finds 5 cities, a mining district, a lake, and a point-of-interest. There are
`378 San Francisco’s in the Gazetteer. The user can select the appropriate member from the list.
`The map control displays the 40-km map of that area. The user can then pan and zoom with this
`map application, and can select the USGS and SPIN-2 images for the displayed area.
`
`Navigation via coverage map. The USGS gave us a shaded relief map (Mercator projection)
`which includes political (state and province) boundaries. We shaded this map green where we have
`some imagery. Then we built an image pyramid: one image for the whole planet, and two-levels of
`zoom in that covers a continent and then a region. The bottom panels of the previous page show an
`example of zooming in on New York City. We added this interface last, but it is the most popular
`way to navigate the database.
`
`Spatial navigation via the map control. A dynamic HTML page allows the client browser and to
`talk with the Microsoft Expedia™ map server (http://www.expediamaps.com/) that provides the
`basic features of Microsoft Encarta World Atlas™ and Microsoft Automap Streets™ as GIF
`images. The applet lets users pan and zoom over graphic images of the earth and of US street
`maps. The applet decides what the client wants to see and sends a request for that map to the
`Expedia map server at http://maps.expedia.msn.com/. That server, given the corners of a rectangle
`and an altitude, generates the view of the earth inside that rectangle. It generates a GIF image that
`is downloaded to the applet in the client browser. The map server is provided by MSN to any
`Internet customer. We have just wrapped it in our Java applet. This app works on Windows,
`Macintosh, and UNIX clients. Coverage map and spatial access is especially convenient for those
`who do not understand English.
`
`Zooming in and out: The map controls allows the browser to zoom out and see a larger area, or
`zoom in and see finer detail. The coarsest view shows the whole planet. The user can "spin" the
`globe to see the "other side" and place the point of interest in the center of the screen. Then the
`user can zoom in to see fine detail. Where we have street maps (Microsoft Automap® Streets), the
`zoom can go all the way down to a neighborhood.
`
`Moving Around: Once you find
`the spot you are looking for,
`you can see nearby places by
`pushing navigation buttons to
`pan and zoom. Doing this,
` you can "drive"
` cross-country.
`
` .
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`Encarta, USGS, and SPIN-2 Themes: TerraServer has several different views of the earth: the
`coverage map view, the Encarta World Atlas view, the USGS image view, and the
`Sovinformsputnik-SPIN-2 view. We call each of these a theme. The user may switch from one
`theme to another: perhaps starting with the Encarta theme, then the SPIN-2 theme, and then the
`USGS theme of the same spot. With time, we expect to have multiple images of the same spot.
`Then the user will be able to see each image in turn. Your grandchildren will be able to see how
`your neighborhood evolved since 1990.
`
`Download: If you like the SPIN-2 imagery or USGS image, you can push the "DownLoad Image"
`button. That takes you to the Aerial Images or USGS Site Server. Both Aerial Images and USGS
`E-commerce sites run Microsoft’s Commerce Server(cid:228)
`, which is a component of Microsoft Site
`Server. That is where the similarity between Aerial Images and the USGS e-commerce site ends.
`The Aerial Images web site allows Internet users to select one of three sizes for a digital image.
`The user can also select a choice of format (TIF or JPEG) and can have also have a photograph
`printed and delivered over-night by Kodak.
`
`The USGS site allows users to download the image viewed on Microsoft TerraServer as a single
`digital image in JPEG format at no charge. The USGS site offers an easy method to purchase one
`or more of the original data sets used to form these images. The original USGS imagery is intended
`for use by professional GIS users. The Site Server allows you to shop for imagery and quotes you a
`price. If you want to purchase a high-quality digital copy of these images, Site Server asks for your
`credit card, debits it, and downloads the images you purchased or ships them to you on the media of
`your choice.
`
`The USGS and SPIN2 sites are a good example of selling soft goods over the Internet.
`
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`Server Design
`The TerraServer has several components that combine to make a seamless Internet application.
`
`TerraServer
`
`SQL
`Server
`
`2.3 TB
`Database
`
`IE
`
`HTTP
`
`IIS
`
`HT
`TP
`
`ODBC
`HT
`TP
`
` Internet Information Server and Active Server Pages: Clients send requests to the
`TerraServer’s Internet Information Server (IIS) built into Windows NT. These
`requests are passed to Active Server Pages (ASPs) programmed in VBscript. These
`ASPs, programmed in VBscript send queries to stored procedures in the SQL
`Server database to query the Gazetteer and to fetch image tiles. The ASPs
`dynamically construct the HTML web pages needed to mosaic the tiles together to
`make a complete image. The server first returns the HTML for the outer frame, and
`the HTML table referencing the two dimensional array of tiles. The number of tiles
`display in the HTML table is controlled by the user and the current page’s image
`resolution. TerraServer stores imagery in 32m/p (square meters/pixel), 16 m/p,
`8m/p, and full resolution (1m/p or 1.56m/p). The user decides if they want to see a
`small, medium, or large view. A full resolution “small” view page display 4 image
`tiles whereas a “large” view page displays 16 image tiles. A 32m/p web pages
`range from 64 tiles in a “small” view to 256 image tiles in a “large” view. When the client pans an
`image, 50% of the images on the current frame are moved to another location within the frame and
`the other 50% are downloaded from the database.
`
`Site
`Encarta
`Server
`Map Server
`TerraServer hardware and software
`
`The VBscript program dynamically creates the necessary HTML to render that image. It sends this
`HTML back to the client's browser. The client browser then requests the images needed to fill in
`the picture. Depending on the image size the user selects, this can be between 4 and 256 tiles.
`These URL requests generate between 30 and 500 database accesses.
`
`Tiled Image Database: The database stores both the USGS data and the SPIN2 data as small (10
`kilobyte or less) tiles compressed with JPEG. Larger images are created as a mosaic of these tiles.
`This allows quick response to users over slow voice-grade phone lines. It also allows the
`application to pan and zoom across the images.
`
`Gazetteer: The Encarta World Atlas Gazetteer has over a million entries describing most places on
`earth. All these records are stored and indexed by Microsoft SQL Server. Stored procedures to
`look up these names and produce an HTML page describing the top 10 "hits", with hot-links to the
`images if they are in the TerraServer.
`
`TerraServer uses SQL Server 7.0: TerraServer uses the 1998 version of Microsoft SQL Server.
`This version supports larger page sizes, has better support for multi-media, supports parallelism
`within queries, parallel load, backup and restore utilities, and supports much larger databases.
`TerraServer has been a good stress test for SQL Server 7.0.
`
`Loading the Database: SOVINFORMSPUTNIK and the USGS delivered the data to us on several
`hundred tapes. We had to sort, reformat, slice, and dice this data before it could be inserted in to
`the database. We wrote several programs to do this image processing. We also wrote a load
`manager that consumes these files and feeds the data into the TerraServer using the SQL Server
`loader APIs (ODBC BCP). Using several parallel streams, it loads at approximately 2 MBps. At
`this rate, the load takes 6 days. The load is more constrained by the scan, slice, and dice process
`than by the SQL load rate. Indeed, the database load rate is 15 MBps, eight times faster than the
`load program can produce the data.
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`Site Server: If a client wants to buy some Imagery from Aerial Images, the client pushes the Down
`Load Image button. Site server uses secure HTTP to authenticate the user, quote the user a price
`for the requested data. The data providers, Aerial Images and the USGS, have built electronic
`“stores” tailored to their existing products and their markets. The sites differ in pricing
`philosophies and market focus. The Aerial Images site is designed for unsophisticated users.
`Imagery size and formats are designed to be attractive to non-professional users interested in a
`digital photo of a small area. The USGS site on the other hand, is targeted towards the USGS’
`traditional market of GIS professionals and data resellers. Both systems use credit
`cards as authorization for payment. Aerial Images’ site downloads digital images
`immediately over the user’s internet connection. Paper photographs are delivered
`via ground mail or overnight express services. USGS images are distributed via
`ground mail carriers only.
`
`The diagram below describes how Microsoft TerraServer integrates with the E-
`Commerce web sites operated by the USGS and SPIN-2 organizations. Web users
`access Microsoft TerraServer through their PC connected to the Internet. Microsoft
`TerraServer web application is built with IIS 4.0 Active Server Pages. The Active
`Server Pages access the TerraServer SQL database to built HTML pages and
`references to image objects contained in the TerraServer Sphinx database. The
`HTML pages are sent over the internet to the web user’s PC. The “Download”
`button on each Microsoft TerraServer image page opens a URL document at the data
`provider commerce site.
`
`The USGS electronic commerce site runs on Microsoft Commerce Server on a
`computer system located at the USGS EROS Data Center in Sioux Falls, South
`Dakota. The Microsoft Commerce Server application was written by the USGS staff
`members and integrates into the USGS’ automated order entry, inventory, and
`shipping systems. The Microsoft Commerce Server handles the creation of the
`order and all payment reconciliation between the web user and the USGS’ bank
`institution. The USGS site is secured using SSL technology and certificates
`obtained through VeriSign.
`
`Customers can buy the right to use
`SPIN2 images. They may also buy a
`Kodak print of the image. Larger
`images are more expensive. USGS
`offers similar services for its data. All
`this commerce is performed by
`Microsoft Site Servers operated by
`SPIN2 and USGS.
`
`The USGS electronic Store: The USGS electronic store is designed for professional image users.
`The USGS distributes Microsoft TerraServer images to web users at no charge. These images are
`“Jpeg compressed” images that do not have the image quality required for certain professional
`applications. The USGS electronic store enables professional users to purchase the same
`uncompressed imagery used to create the Jpeg images stored in the Microsoft TerraServer database.
`Because of the size of the uncompressed imagery, which is typically 46MB per file, the USGS
`distributes uncompressed imagery on CDROM media.
`
`The SPIN-2 Commerce Server: The SPIN-2 commerce site runs on Microsoft Commerce Server
`on a DEC Alpha 800 server located at Aerial Images, Inc. in Raleigh, North Carolina. The SPIN-2
`electronic commerce site is intended to be used by either professional or non-professional users
`requiring images that are physically larger than images they can view on Microsoft TerraServer.
`At the SPIN-2 store, users can select the physical size of the image, the type of image format, and
`output media. In addition to a digital image, users can opt for a photographic print of their selected
`image in one of three sizes ranging from 8 ½ x 11” to 20” x 26” prints. SPIN-2 will forward your
`digital image to Kodak for processing.
`
`Commerce Server talks to the banks: The Microsoft Commerce Server application steps the user
`through the selection process, obtains their payment information, and connects to SPIN-2’s bank
`through PayLinks, a third-party payment component that integrates with Microsoft Commerce
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`Server. Once the credit card information is validated, the Commerce application inserts an order
`into the SPIN-2 “TerraShop Database”.
`
`How TerraShop delivers data to the customer. A custom program picks up the order from the
`TerraShop database, constructs the image requested by the user and routes the image to the
`appropriate locations. The digital image is output to a “customer pickup area” on the SPIN-2 web
`site. The purchaser is sent an e-mail message notifying them that their order is ready to pickup. If a
`paper print was ordered, the digital image is electronically placed in the “Kodak pick up area”. At
`regular intervals, Kodak’s automated operation picks orders up for printing and delivery the same
`day.
`
`Four web sites working together: The Microsoft TerraServer is not only a huge database but it is
`also an example of how to build a distributed electronic store. Four separate web sites located at
`opposite ends of the United States seamlessly interoperate to provide interactive shopping, payment
`processing, and product delivery
`
`Summary: TerraServer is a new world atlas — far larger than any seen before. It is a relatively
`simple database application, but it demonstrates how to build a real Internet application using
`WindowsNT and SQL Server running on Compaq AlphaServer 8400 and StorageWorks servers.
`
`TerraServer Web Site
`
`Data Provider Commerce Web Site
`
`TerraServer
`Active Server Pages
`
`Downlload Image Button
`
`Internet
`
`Data Provider
`E-Store
`Active Server Pages
`
`Microsoft
`Commerce
`Server
`
`S hopper & R eceipt History
`
`Purchased
`
`Image
`
`Image Delivery
`
`.JPG or .TIF
` Images
`
`TerraShop
`Database
`
`Terra Server
`SQL Database
`
`How the Microsoft TerraServer and the USGS and SPIN-2 Commerce Servers
`cooperate to deliver data to customers.
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`Database Design
`
`The TerraServer presents an interesting geo-spatial database design problem. It contains data from
`three different sources represented in different coordinate systems. It has to integrate all this data
`into a single intuitive user interface. This section describes how the data is represented in the
`database and how it is indexed.
`
`Coordinate Systems
`The earth is not flat. It is not round either -- it is a bumpy oblate spheroid. When measuring the
`earth at one-meter resolution, this becomes a very important issue.
`
`90º =
`107 m
`
`6º ~ 2/3 106 m
`UTM divides the earth into 60
`zones. The continental US
`occupies 10 of them.
`
`USGS DOQs: The USGS has aerial photographs of most of the United States. It has
`corrected these aerial photographs for elevation and camera optics. The USGS then maps
`the true image into the Universal Transverse Mercator (UTM) coordinate system. The
`resulting digital images are mosaiced into Digital Orthorectified Quarter Quadrangles
`(DOQQs for short). A quadrangle is a one-eighth degree square (about 3.5 kilometers on a
`side). The USGS has published paper quadrangle maps for many decades. A DOQQ is
`one-quarter of a USGS quadrangle.
`
`The UTM system: UTM divides the earth into 60 zones. Each zone is two 6º spherical
`triangles going from the equator to the poles. The continental United States occupies nine
`UTM zones (Alaska and Hawaii add 7 more zones). A UTM projection flattens each of
`these spherical triangles (projects them onto a plane). The meridian of the triangle is
`represented perfectly, but all the other pixel-points are slightly distorted to be trapezoids
`rather than squares. In particular, the pixels at the edges of a zone have north at 3º from
`the vertical. The UTM system maps latitude lines into curves. This is barely noticeable to
`the eye, but is very noticeable when images that lie on zone boundaries are concatenated.
`
`USGS data uses UTM: We decided to use the USGS coordinate system for the USGS
`data. To be exact, the USGS uses UTM with the NAD83 datum. It would be too much
`work for us to remap the USGS data into a coordinate system that gives a seamless mosaic of the
`earth. In UTM, each point has a zone number, then a Northing (meters from the equator), and an
`Easting (meters from the west meridian of the triangle). TerraServer USGS images are a fixed size
`– 1800 meters by 1200 meters. The TerraServer assigns a unique UGridID to each TerraServer
`image by concatenating the UTM zone with the image’s Easting ID (Easting + 400 / 1800) number
`followed by a bit interleave of the Northing ID (Northing / 1200). The bit interleaving causes
`nearby images to have a common UGridID prefix.
`
`SPIN-2 uses latitude-longitude: The SPIN2 data is taken from 200 kilometers up. An original
`SPIN-2 image is a 40-km by 160-km photographic swath taken by a former Russian military
`satellite. These are declassified photos. A recent US-Russian treaty allows Russia to export to the
`United States. Each photo has a resolution of 1.56 square meters per pixel. We have 2 trillion
`square meters of these images (0.7 TB). Each 40km by 160km photograph is scanned into four
`separate 40km X 40km image because it is too large to scan all at one. The digital scan is separated
`into four separate 20km X 20km files because Adobe Photoshop cannot rotate an image larger than
`30,000 pixels. Aerial Images personnel geo-locate five points on one 20km by 20km image.
`Photoshop is used to rotate each 20km by 20km quadrant. This creates the appearance of a
`
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`

`diamond shaped photo within a square white canvas. The upper left corner point and lower right
`corner point of the square image is computed. The upper left and lower right corner points of the
`other three images are computed relative the first image. Our image editing program reads each
`“Spin-2” 20km X 20km image and creates “TerraServer SPIN-2” images that are 1/48th of degree
`wide by 1/96th of a degree high. Pixels from adjacent 20km X 20km image are merged creating a
`single “TerraServer” Spin-2 image. We mapped the SPIN2 data into a latitude-longitude reference
`system -- each image is given a unique Z-Grid ID, which is the interleaving of the latitude and
`longitude of the center point of the TerraServer SPIN-2 image. On earth, there are a total of
`298598400 unique ZgridID values. ((360 longitude degrees * 48 ‘cuts per degree’) x (180 latitude
`degrees x 96 ‘cuts per degree’))
`
`The Microsoft TerraServer
`
`10
`
`Microsoft Corp. Exhibit 1034
`
`

`

`Image Format
`Images are 256-level gray scale JPEG: Browsers generally reduce the number of levels displayed.
`The images are all stored JPEG compressed to 80% be faithful to the original image. This typically
`gives a 5:1 compression.
`
`The image tile pyramid: The images are stored in the database as an image pyramid so that users
`can zoom in and out (see Figure 1). An additional constraint is that no image should be much larger
`than 10KB. This constraint comes from the need to support clients accessing the database via 28.8
`kbps modems. It takes about 3 seconds to download 10KB image. A complete web page is made
`as mosaics of these small images.
`
`Tile, thumb, browse, and jump images: Large images are first sliced into tiles that are about 10
`kilobytes each. Each of these tiles covers a tiny area (less than a tenth of a square kilometer).
`The TerraServer returns a mosaic of these tiles to the user on each query. Coarser tile resolutions
`are stored to support zooming. The data load process mosaics tiles and then dithers them down to
`wider-panorama images. For USGS data, an 8x8 mosaic is dithered down to 8-meter resolution
`produces a browse image from the original images. For the SPIN2 1.56-meter data, 5x5 array of
`tiles is dithered to form the browse image. These browse images are further dithered down to 16-
`meter (thumbnail image) and 32-meter (jump image) resolution images. Because these images
`have lower resolution, they occupy 1/64th, 1/256th, and 1/1024th of the space of the tile images. That
`is, they occupy almost no space at all.
`
`1:1
`
`1:1
`
`64:1
`
`Jump image
`1 pixel =
`32x32 m2
`Dithered Thumbnail image
`1 pixel = 16x16 m2
`
`USGS Tile image
`DOQ of Washington Monument
`1 pixel = 1 sq meter
`Figure 1: The fine-resolution images of the Washington Monument are used to make an 8x8 mosaic. That mosaic is
`dithered to an image where one pixel is 8x8 meters. This thumbnail image is then dithered down to a 16x16 meter
`browse image and a 32x32 meter jump image. The TerraServer mosaics these