Frank, I do not know whether the new fixes would help or not. When I calculate the statistics with ArcGIS, no .aux.xml file is generated. I believe ArcGIS is storing the statistics in a .aux file instead. Here is the sequence of events that suggests it.
1. I created a 8192x4096 float32 .tif file with GDAL: 09/17/2009 04:53 PM 134,284,081 sst2004d.tif 2. I started ArcCatalog, navigated to the directory containing the file, and selected it. Selecting it does not actually display anything but nonetheless causes ArcCatalog to create a .aux file: 09/17/2009 05:12 PM 5,056 sst2004d.aux 09/17/2009 04:53 PM 134,284,081 sst2004d.tif 3. I right-clicked, selected Properties, and observed that there were no statistics. (This operation did not touch the files.) I executed the ArcGIS Calculate Statistics tool on the file. This touched the .aux file and created a .xml file: 09/17/2009 05:16 PM 36,591 sst2004d.aux 09/17/2009 04:53 PM 134,284,081 sst2004d.tif 09/17/2009 05:16 PM 566 sst2004d.tif.xml That XML file only contains metadata; a record of the processing: <?xml version="1.0"?> <!--<!DOCTYPE metadata SYSTEM "http://www.esri.com/metadata/esriprof80.dtd">--> <metadata xml:lang="en"><Esri><MetaID>{A1793984-B9D0-4F32-A6D1-AB1C79D6AB29}</MetaID>< CreaDate>20090917</CreaDate><CreaTime>17163000</CreaTime><SyncOnce>TRUE</Syn cOnce><DataProperties><lineage><Process ToolSource="C:\Program Files\ArcGIS\ArcToolbox\Toolboxes\Data Management Tools.tbx\CalculateStatistics" Date="20090917" Time="171630">CalculateStatistics C:\Temp2\sst2004d.tif 1 1 # C:\Temp2\sst2004d.tif</Process></lineage></DataProperties></Esri></metadata> Given that the .tif itself was not touched, it seems that the statistics were stored in the .aux file. If this is true, do you think ArcGIS will pay attention to the .aux.xml file that GDAL will generate? I don't know much about this stuff so your guess is better than mine. Also, please disregard my previous claim that ArcGIS 9.3.1 was not able to recognize the NoData value written by the GTiff driver. I got confused about which machine I was using and tested that scenario with ArcGIS 9.1. I can confirm that ArcGIS 9.3.1 does recognize the NoData value properly in the scenario above. Jason -----Original Message----- From: Frank Warmerdam [mailto:warmer...@pobox.com] Sent: Thursday, September 17, 2009 3:58 PM To: Jason Roberts Cc: 'Riki Tiki'; gdal-dev@lists.osgeo.org Subject: Re: [gdal-dev] Re: Jason Roberts wrote: > Riki, > > Please let us know whether Frank's suggestion works or not. I have been > experimenting with writing GeoTIFFs using GDAL 1.6.0 and the Python bindings > and have not been successful so far at using GDAL to calculate statistics > that ArcGIS recognizes. It would be interesting to know whether this > suggestion will work. > > If anyone is interested, after creating a GTiff with one band, writing > values to the band, flushing the cache, I have been calling > > band.SetStatistics(*band.GetStatistics(False, True)) > > and then looking at the resulting file from ArcGIS 9.3.1 (the latest > version). ArcGIS reports that there are no statistics. I can then calculate > them with ArcGIS, if desired, but like Riki, it would be useful if I did not > need to do this. Jason, I notice that if I run gdalinfo -stats from trunk I get the stats written to the .aux.xml file while I don't from the 1.6 branch. I think this is something that has been fixed recently. I'd suggest working from trunk if that is at all practical. If it is important, I could backport some of the statistics retaining fixes back to 1.6 branch. Best regards, -- ---------------------------------------+------------------------------------ -- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev