Frank,<br><br>The reason why I had:<br>OUTPUTFORMAT<br> NAME png<br> DRIVER "GD/PNG"<br> MIMETYPE "image/png"<br> IMAGEMODE RGB<br> EXTENSION "png"<br> END<br>listed was that for ECW files you had DRIVER "GDAL/JP2ECW" and I am wondering if you need a special driver for Imagine format.
<br><br>In the next few months I may have to ingest 2500 DVD's of GeoTiff imagery data covering portions of the United States with each DVD contain 1 image of about 1.1 GB in size. In looking over the MapServer Raster documentation I could do the following:
<br><br>a.) Keep as GeoTiff format<br> 1.) Convert all the images from whatever their current projection is to WGS84 using GDALWARP.<br> 2.) Build internal tiling to each GeoTiff image utilizing: gdal_translate -co TILED=YES
orig.tif tiled.tif<br> 3.) Build internal overviews using: gdaladdo -r average *.tif 2 4 8 16 32 64 128<br> 4.) Build external tiling using: gdal_index doq_index.shp doq/*.tif This will link all the geotiff's in the doq folder to the doq_index.shp, which then is referenced in tileindex within layer instead of DATA.
<br> 5.) ?When using tile indexes to manage many raster files as a single file, it is especially important to have a overview layer that kicks in at high (should'nt this say low instead?) scales to avoid having to open a large number of raster files. Building external overviews use either gdal_merge or gdalwarp (eg gdalwarp -rc -tr 250 250 doq/*.tif
overview.tif) The 250 within the gdalwarp statement means a output resolution of 250 meters?<br><br>b.) Convert from GeoTiff to Imagine format<br> 1.) Convert all the images from whatever their current projection is to WGS84 using GDALWARP.
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2.) Mosaic all the GeoTiff's and convert to Imagine format using: gdalwarp -of HFA doq/*.tif tiled.img<br> 3.) Build internal overviews using: gdaladdo -r average tiled.img 2 4 8 16 32 64 128<br><br>Which method would you recommend a or b as far as performance?
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<br>Thanks,<br><br>John J. Mitchell <br> <span style="text-decoration: underline;"><span style="text-decoration: underline;"></span></span><br><br><br><div><span class="gmail_quote">On 12/16/06, <b class="gmail_sendername">
Frank Warmerdam</b> <<a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
John Mitchell wrote:<br>> Hi,<br>><br>> I have been reading over the mapserver raster documentation and I have a<br>> few questions:<br>><br>> 1.) It mentioned a 4 gb limit for GeoTiff files. Is this for GeoTiff
<br>> files or that GeoTiff's can only be tiled up to 4 gb. Is this 4 gb<br>> limit an issue with mapserver or GeoTiff.<br><br>John,<br><br>The 4GB limit is inherent in TIFF, and it isn't specific to mapserver<br>in any way. Note that you can setup a tile index with my TIFF files
<br>smaller than 4GB. There is no meaningful limit on the amount of data<br>that can be in a tileindex.<br><br>> 2.) Assuming the 4 gb GeoTiff limit then the GeoTiff would need to be<br>> converted to Erdas Imagine (HFA) format. The Documentation said that
<br>> the Imagine format is already Tiled. Correct?<br><br>Imagine format is inherently tiled, normally with 64x64 blocks.<br><br>> 3.) Is the format the same to access an Imagine file as it is to access<br>> a GeoTiff? I have a sample .map segment that I use to access a GeoTiff:
<br><br>Yes, Imagine files are accessed the same way in mapserver as GeoTIFF files<br>are.<br><br>> OUTPUTFORMAT<br>> NAME png<br>> DRIVER "GD/PNG"<br>> MIMETYPE "image/png"<br>> IMAGEMODE RGB
<br>> EXTENSION "png"<br>> END<br><br>I'm not sure why this OUTPUTFORMAT declaration is in your email. It didn't<br>seem to relate to the text of question 3. But I will say that output formats<br>is to some degree a distinct issue from input raster formats.
<br><br>Best regards,<br>--<br>---------------------------------------+--------------------------------------<br>I set the clouds in motion - turn up | Frank Warmerdam, <a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com
</a><br>light and sound - activate the windows | <a href="http://pobox.com/~warmerdam">http://pobox.com/~warmerdam</a><br>and watch the world go round - Rush | President OSGeo, <a href="http://osgeo.org">http://osgeo.org
</a><br><br></blockquote></div><br><br clear="all"><br>-- <br>John J. Mitchell