GeoTIFF Format Specification.docx

1、GeoTIFF Format SpecificationGeoTIFF Format SpecificationGeoTIFF 格式规范GeoTIFF Revision 1.0 第一版+-+Specification Version: 1.8.2规范版本:1.8.2Last Modified: 10 November, 1995最后更新日期：1995年11月10日Authors:作者：Niles Ritter, Jet Propulsion Laboratory 喷气推进实验室Cartographic Applications Group 地图应用小组4800 Oak Grove Dr.Pas

2、adena, CA 91109email:*.nasa.govMike Ruth, SPOT Image Corp SPOT影像公司Product Development Group 产品开发部1897 Preston White Dr.Reston, VA 22091email:*Acknowledgments:感谢：GeoTIFF Working Group: GeoTIFF工作组：Mike Ruth, Niles Ritter, Ed Grissom, Brett Borup, George Galang,John Haller, Gary Stephenson, Steve Covin

3、gton, Tim Nagy,Jamie Moyers, Jim Stickley,Joe Messina, Yves Somer.Additional advice from discussions with Tom Lane, Sam Leffler regardingTIFF implementations.Roger Lott, Fredrik Lundh, and Jarle Land provided valuable informationregarding projections, projection code databases and geodetics.GeoTIFF

4、Mailing list:Posting: *.nasa.govSubscription: *.nasa.gov(send message subscribe geotiff your-name-here).Disclaimers and Notes for This Version:免责声名：This proposal has not been approved by SPOT, JPL, or any other organization. This represents a proposal, which derives from many discussions between an

5、international body of TIFF users and developers.The authors and their sponsors assume no liability for any special, incidental, indirect or consequences of any kind, or any damages whatsoever resulting from loss of use, data or profits, whether or not advised of the possibility of damage, and on any

6、 theory of liability, arising out of or in connection with the use of this specification.Copyright版权说明Portions of this specification are copyrighted by Niles Ritter and MikeRuth. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distribut

7、ed for direct or commercial advantage and this copyright notice appears.Licenses and Trademarks 许可与注册商标Aldus and Adobe are registered trademarks, and TIFF is a registeredtrademark of Aldus Corp., now owned by Adobe. SPOT Image, ESRI, ERDAS,ARC/Info, Intergraph and Softdesk are registered trademarks.

8、ConcurrenceThe following members of the GeoTIFF working group have reviewed andapproved of this revision.Name Organization Representing- - -Niles Ritter Jet Propulsion Labs JPL Carto GroupMike Ruth SPOT Image Corp. (USA) SPOT Image Corp.(USA)+-+Table of Contents 内容表+-+-+1 Introduction 1简介+-+-+1.1 Ab

9、out this Specification1.1关于规范This is a description of a proposal to specify the content and structure of a group of industry-standard tag sets for the management of georeference or geocoded raster imagery using Aldus-Adobes public domain Tagged-Image File Format (TIFF).This specification closely fol

10、lows the organization and structure of the TIFF specification document.+-+1.1.1 BackgroundTIFF has emerged as one of the worlds most popular raster file formats. But TIFF remains limited in cartographic applications, since no publicly available, stable structure for conveying geographic information

11、presently exists in the public domain.Several private solutions exist for recording cartographic informationin TIFF tags. Intergraph has a mature and sophisticated geotie tagimplementation, but this remains within the private TIFF tagsetregistered exclusively to Intergraph. Other companies (such as

12、ESRI,and Island Graphics) have geographic solutions which are alsoproprietary or limited by specific application to their softwaresarchitecture.Many GIS companies, raster data providers, and their clients haverequested that the companies concerned with delivery and exploitationof raster geographic i

13、magery develop a publicly available, platforminteroperable standard for the support of geographic TIFF imagery. SuchTIFF imagery would originate from satellite imaging platforms, aerialplatforms, scans of aerial photography or paper maps, or as a result ofgeographic analysis. TIFF images which were

14、supported by the publicgeotie tagset would be able to be read and positioned correctly inany GIS or digital mapping system which supports the GeoTIFFstandard, as proposed in this document.The savings to the users and providers of raster data and exploitationsoftwares are potentially significant. Wit

15、h a platform interoperableGeoTIFF file, companies could stop spending excessive developmentresource in support of any and all proprietary formats which areinvented. Data providers may be able to produce off-the-shelf imageryproducts which can be delivered in the generic TIFF format quicklyand possib

16、ly at lower cost. End-users will have the advantage ofdeveloped software that exploits the GeoTIFF tags transparently. Mostimportantly, the same raster TIFF image which can be read and modifiedin one GIS environment may be equally exploitable in another GISenvironment without requiring any file dupl

17、ication or import/exportoperation.+-+1.1.2 HistoryThe initial efforts to define a TIFF geotie specification began underthe leadership of Ed Grissom at Intergraph, and others in the early1990s. In 1994 a formal GeoTIFF mailing-list was created andmaintained by Niles Ritter at JPL, which quickly grew

18、to over 140subscribers from government and industry. The purpose of the list is todiscuss common goals and interests in developing an industry-wideGeoTIFF standard, and culminated in a conference in March of 1995hosted by SPOT Image, with representatives from USGS, Intergraph, ESRI,ERDAS, SoftDesk,

19、MapInfo, NASA/JPL, and others, in which the currentworking proposal for GeoTIFF was outlined. The outline was condensedinto a prerelease GeoTIFF specification document by Niles Ritter, andMike Ruth of SPOT Image.Following discussions with Dr. Roger Lott of the European PetroleumSurvey Group (EPSG),

20、the GeoTIFF projection parametrization method wasextensively modified, and brought into compatibility with both the POSCEpicentre model, and the Federal Geographic Data Committee (FGDC)metadata approaches.+-+1.1.3 ScopeThe GeoTIFF spec defines a set of TIFF tags provided to describe allCartographic

21、information associated with TIFF imagery that originatesfrom satellite imaging systems, scanned aerial photography, scannedmaps, digital elevation models, or as a result of geographic analyses.Its aim is to allow means for tying a raster image to a known modelspace or map projection, and for describ

22、ing those projections.GeoTIFF does not intend to become a replacement for existing geographicdata interchange standards, such as the USGS SDTS standard or the FGDCmetadata standard. Rather, it aims to augment an existing popularraster-data format to support georeferencing and geocoding information.T

23、he tags documented in this spec are to be considered completelyorthogonal to the raster-data descriptions of the TIFF spec, and imposeno restrictions on how the standard TIFF tags are to be interpreted,which color spaces or compression types are to be used, etc.+-+1.1.4 FeaturesGeoTIFF fully complie

24、s with the TIFF 6.0 specifications, and itsextensions do not in any way go against the TIFF recommendations, nordo they limit the scope of raster data supported by TIFF.GeoTIFF uses a small set of reserved TIFF tags to store a broad rangeof georeferencing information, catering to geographic as well

25、asprojected coordinate systems needs. Projections include UTM, US StatePlane and National Grids, as well as the underlying projection typessuch as Transverse Mercator, Lambert Conformal Conic, etc. Noinformation is stored in private structures, IFDs or other mechanismswhich would hide information fr

26、om naive TIFF reading software.GeoTIFF uses a MetaTag (GeoKey) approach to encode dozens ofinformation elements into just 6 tags, taking advantage of TIFFplatform-independent data format representation to avoid cross-platforminterchange difficulties. These keys are designed in a manner parallelto st

27、andard TIFF tags, and closely follow the TIFF discipline in theirstructure and layout. New keys may be defined as needs arise, withinthe current framework, and without requiring the allocation of new tagsfrom Aldus/Adobe.GeoTIFF uses numerical codes to describe projection types, coordinatesystems, d

28、atums, ellipsoids, etc. The projection, datums and ellipsoidcodes are derived from the EPSG list compiled by the PetrotechnicalOpen Software Corporation (POSC), and mechanisms for adding furtherinternational projections, datums and ellipsoids has been established.The GeoTIFF information content is d

29、esigned to be compatible with thedata decomposition approach used by the National Spatial DataInfrastructure (NSDI) of the U.S. Federal Geographic Data Committee(FGDC).While GeoTIFF provides a robust framework for specifying a broad classof existing Projected coordinate systems, it is also fully extensible,permitting internal, private or proprietary information storage.However, since this standard arose from the need to avoid multipleproprietary encoding systems, use of private implementations is to bediscouraged.+-+1.2 Revision NotesThis is the final release of GeoTIFF Revision 1.