Any chance this could be added to the Grass wiki as a FAQ? Thanks, Jerry ---- Original message ---- >Date: Wed, 10 Oct 2007 15:56:43 -0700 (PDT) >From: al furqon lebo <[EMAIL PROTECTED]> >Subject: Re: [GRASS-user] Export of GeoTIFF >To: Michael Barton <[EMAIL PROTECTED]>, [EMAIL PROTECTED], >[email protected] > > GRASS Data To ArcView > This document will show the procedure to export > GRASS raster and vector data to > ArcView. > GRASS Vector Data to ArcView 2.1/3.0 > 1) In GRASS use the v.out .ascii command on the > vector file you wish to export. > 2) In GRASS use the v.out.dxf command on the ascii > file you created above. When > GRASS prompts you for a dxf file name, type in the > name with extension(i.e. > soils.dxf). The .dxf extension will be needed for > ArcView. > Please note that dxf files can only be displayed in > ArcView 2.1(MS Windows) and > ArcView 3.0(UNIX and MS Windows). > 3) To display the dxf file in ArcView you first need > to open a VIEW then add a > theme(Feature Data Source). The dxf file should be > selectable on the screen. Open > the dxf file. You have to convert the dxf file to a > shapefile in order to change > projection etc. > GRASS Raster Data To ArcView 2.1/3.0 > This procedure will georeference a raster image > within ArcView! > 1) In GRASS use the r.out.tiff command on the Raster > file you wish to export. Use > defaults for the command! In particular DO NOT use > the LZW compression! This > may make your file unreadable in ArcView. The GRASS > generated TIFF file should > have a tiff extention(i.e. photo1.tif) > 2) After making the TIFF file goto your "cellhd" > sub-directory! > 3) Cat the raster cellhd file you exported! You will > use the information in this file to > build a world file. A world file is a ascii file > ArcView uses to georeference information > for the TIFF file you created. With the world file > your TIFF file will be georeference in > ArcView. > 4) Start a vi session, name the file the same as > your TIFF file except with a different > extention! Use the extention .tfw (i.e. photo1.tfw > ). You will enter six lines of > information in your vi session. You can use this > file as a base for future world file. > Below is the possible contents of a typical world > file. > 10.0 > 0.0 > 0.0 > -10.0 > 590005 > 4927995 > Below is the possible contents of a typical GRASS > cellhd file. > proj: 1 > zone: 16 > north: 4928000.000000 > south: 4914000.000000 > west: 590000.000000 > east: 609000.000000 > n-s resol: 10.000000 > e-w resol: 10.000000 > format: 1 > compressed: 0 > Below is the information you will need to create the > above world file(tfw). Please note > that the world file contains information in your > GRASS cellhd file! Information on the > world file can be found in ArcView 3.0 manual on > page 301. > World File GRASS Cellhd File Description > 10.0 "e-w resol:" Size of pixel in x direction. > 0.0 N\A Rotation term for row(usually 0). > 0.0 N\A Rotation term for column(usually 0). > -10.0 "n-s resol:" Size of pixel in y direction(- > sign is needed!) > 590005 "west" + 1/2 "e-w resol" The x coordinate of > pixel in upper left corner. * > 4927995 "north" - 1/2 "n-s resol" The y coordinate > of pixel in upper left corner. * > Pixel 1,1 * ArcView georeferences the center of the > pixel while GRASS > uses the NW edge in the cellhd file. Thus a slight > adjustment is > needed to correctly georeference a TIFF file in > ArcView. For these > lines you need to add one half the pixel > resolution(west) and subtract > one half the pixel resolution(north). > 5) Place your TIFF and world file in the same > directory. These files now can be used > in ArcView and should be georeferenced correctly!. > A sample world file call be found at the NCG FTP > Site! The NCG FTP is listed below. > ftp.ftw.nrcs.usda.gov (goto the /outgoing directory! > and get the file "base.tfw") > If You have any questions please contact me at your > convenience. > Tony Kimmet > (817)-334-5212 x3062 > [EMAIL PROTECTED] > > Michael Barton <[EMAIL PROTECTED]> wrote: > > ESRI needs special GeoTiff options to be enabled. > These are documented on the r.out.gdal manual > page--near the bottom where I missed them too > awhile back. > > Michael > > On 10/9/07 11:58 PM, "[EMAIL PROTECTED]" > <[EMAIL PROTECTED]> wrote: > > Dear list, > > I have serious problems exporting GRASS DCELL > rasters to GeoTIFF. > I used r.out.gdal with type=Float32 and set the > compression to LZW. > What I got later on in ArcView 3.3 is pure noise > fort he picture and in ArcGIS 9.2 I get some > strange results. > The NULL values of the picture get a cryptic > code like -1#QUAN1 and if there are pixels with > value 0 they become NoData in ArcGIS. > > I need to have them as GeoTIFFs for the easy im- > and export. I am aware that I can also use > r.out.ascii but then I have to do an import > procedure in ArcGIS. For nearly 1000 images that > is a bit hard to do. > > Any hints for the export options? > > Thx in advance, > Christian > > _________________________________________ > > Dipl. Geogr. Christian Braun > Tel: +352- 425991-608 > Mobil: +49-179-6845896 > Mail: [EMAIL PROTECTED] > > Resource Centre for Environmental Technologies, > Public Research Centre Henri Tudor, > Technoport Schlassgoart, > 66 rue de Luxembourg, > P.O. BOX 144, > L-4002 Esch-sur-Alzette, Luxembourg > > __________________________________________ > Michael Barton, Professor of Anthropology > Director of Graduate Studies > School of Human Evolution & Social Change > Center for Social Dynamics & Complexity > Arizona State University > > phone: 480-965-6213 > fax: 480-965-7671 > www: http://www.public.asu.edu/~cmbarton > > _______________________________________________ > grassuser mailing list > [email protected] > http://grass.itc.it/mailman/listinfo/grassuser > > your sincerely > > alf > -_-____02053 > > > > ------------------------------------------------ > > Building a website is a piece of cake. > Yahoo! Small Business gives you all the tools to get > online. >________________ >_______________________________________________ >grassuser mailing list >[email protected] >http://grass.itc.it/mailman/listinfo/grassuser Gerald Nelson Professor, Dept. of Agricultural and Consumer Economics University of Illinois, Urbana-Champaign office: 217-333-6465 cell: 217-390-7888 315 Mumford Hall 1301 W. Gregory Urbana, IL 61801
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