Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
I think the goal of this entire email exchange was to try and understand a bit better where this problem was coming from. I gave my contribution on the software I manage, I won't into gdal/mapserver/qgis, I was hoping to get some feedback from their communities. Cheers, Simone --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Jan 28, 2010 at 12:22 AM, Pablo Carreira pablotcarre...@hotmail.com wrote: BTW, The possibility of the problem is in Qgis and not the server has been contemplated in this investigation? Pablo Torres Carreira Date: Wed, 27 Jan 2010 13:47:46 -0500 From: crschm...@crschmidt.net To: discuss@lists.osgeo.org Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? On Wed, Jan 27, 2010 at 04:35:59PM -0200, Pablo Carreira wrote: Hi Simone, The issue http://jira.codehaus.org/browse/GEOS-3702217is not avaliable. http://jira.codehaus.org/browse/GEOS-3702 Pablo Torres Carreira Date: Wed, 27 Jan 2010 18:39:51 +0100 Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? From: simone.giannecch...@geo-solutions.it To: discuss@lists.osgeo.org Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob: +39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ Sabia que você tem 25Gb de armazenamento grátis na web? Conheça o Skydrive agora. http://www.windowslive.com.br/public/product.aspx/view/5?ocid=CRM-WindowsLive:produtoSkyDrive:Tagline:WLCRM:On:WL:pt-BR:SkyDrive ___ Discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
RE: [OSGeo-Discuss] WCS/WMS accuracy tests?
Hi Simone, The issue http://jira.codehaus.org/browse/GEOS-3702217is not avaliable. Pablo Torres Carreira Date: Wed, 27 Jan 2010 18:39:51 +0100 Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? From: simone.giannecch...@geo-solutions.it To: discuss@lists.osgeo.org Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ Sabia que você tem 25Gb de armazenamento grátis na web? Conheça o Skydrive agora. http://www.windowslive.com.br/public/product.aspx/view/5?ocid=CRM-WindowsLive:produtoSkyDrive:Tagline:WLCRM:On:WL:pt-BR:SkyDrive___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
On Wed, Jan 27, 2010 at 04:35:59PM -0200, Pablo Carreira wrote: Hi Simone, The issue http://jira.codehaus.org/browse/GEOS-3702217is not avaliable. http://jira.codehaus.org/browse/GEOS-3702 Pablo Torres Carreira Date: Wed, 27 Jan 2010 18:39:51 +0100 Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? From: simone.giannecch...@geo-solutions.it To: discuss@lists.osgeo.org Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ Sabia que você tem 25Gb de armazenamento grátis na web? Conheça o Skydrive agora. http://www.windowslive.com.br/public/product.aspx/view/5?ocid=CRM-WindowsLive:produtoSkyDrive:Tagline:WLCRM:On:WL:pt-BR:SkyDrive ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- Christopher Schmidt Web Developer ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Thx Chris, I guess some magic with copy and paste happened before. Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Wed, Jan 27, 2010 at 7:47 PM, Christopher Schmidt crschm...@crschmidt.net wrote: On Wed, Jan 27, 2010 at 04:35:59PM -0200, Pablo Carreira wrote: Hi Simone, The issue http://jira.codehaus.org/browse/GEOS-3702217is not avaliable. http://jira.codehaus.org/browse/GEOS-3702 Pablo Torres Carreira Date: Wed, 27 Jan 2010 18:39:51 +0100 Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? From: simone.giannecch...@geo-solutions.it To: discuss@lists.osgeo.org Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob: +39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ Sabia que você tem 25Gb de armazenamento grátis na web? Conheça o Skydrive agora. http://www.windowslive.com.br/public/product.aspx/view/5?ocid=CRM-WindowsLive:produtoSkyDrive:Tagline:WLCRM:On:WL:pt-BR:SkyDrive ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- Christopher Schmidt Web Developer ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
RE: [OSGeo-Discuss] WCS/WMS accuracy tests?
BTW, The possibility of the problem is in Qgis and not the server has been contemplated in this investigation? Pablo Torres Carreira Date: Wed, 27 Jan 2010 13:47:46 -0500 From: crschm...@crschmidt.net To: discuss@lists.osgeo.org Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? On Wed, Jan 27, 2010 at 04:35:59PM -0200, Pablo Carreira wrote: Hi Simone, The issue http://jira.codehaus.org/browse/GEOS-3702217is not avaliable. http://jira.codehaus.org/browse/GEOS-3702 Pablo Torres Carreira Date: Wed, 27 Jan 2010 18:39:51 +0100 Subject: Re: [OSGeo-Discuss] WCS/WMS accuracy tests? From: simone.giannecch...@geo-solutions.it To: discuss@lists.osgeo.org Hi there, any feedback on this from the gdal/mapserver folks? Anyone looked into my findings? Simone. --- Ing. Simone Giannecchini GeoSolutions S.A.S. Founder - Software Engineer Via Carignoni 51 55041 Camaiore (LU) Italy phone: +39 0584983027 fax: +39 0584983027 mob:+39 333 8128928 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.linkedin.com/in/simonegiannecchini http://twitter.com/simogeo --- On Thu, Dec 10, 2009 at 11:45 PM, Simone Giannecchini simone.giannecch...@geo-solutions.it wrote: Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702217 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ Sabia que você tem 25Gb de armazenamento grátis na web? Conheça o Skydrive agora. http://www.windowslive.com.br/public/product.aspx/view/5?ocid=CRM-WindowsLive:produtoSkyDrive:Tagline:WLCRM:On:WL:pt-BR:SkyDrive ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- Christopher Schmidt Web Developer ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss _ O Novo Windows 7 funciona do jeito que você quer. Clique aqui para conhecer! http://www.microsoft.com/brasil/windows7/default.html?WT.mc_id=1539___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Dear All, I have spent some time investigating this isue with GeoServer trunk. Here: http://jira.codehaus.org/browse/GEOS-3702 you can find a quick detailed report. I am particularly interested in FrankW feedback. Ciao, Simone Steven M. Ottens wrote: On Dec 7, 2009, at 5:47 PM, Stephen Woodbridge wrote: Steven M. Ottens wrote: I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? I wonder if this is the difference between pixel as a point versus pixel as an area. Mapserver uses gdal to handle GeoTiff files and Frank has put a lot of effort in Gdal to handle this correctly. That's our feeling as well. Andrea mentioned that there's an issue with different interpretations on the location of a pixel (centre vs. top-left). Also, I'm surprised that there is any shift in mapserver because I do not think mapserver reprojects data if the in and out projections are the same. I can speak for the other services as I don't know how they work. I'll be doing more detailed tests tomorrow and will post an overview then with the exact versions and configurations and results if people want to reproduce them. I f people have suggestions for specific tests or configurations I'm happy to apply those if possible. Going to test with the latest Geoserver nightly, Mapserver 5.6.0-rc1, Deegree 2.3 rc1 on a windows 2003 machine. With two different GeoTIFFs (one in epsg:4326 and one in epsg:3035) Steven___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss -- View this message in context: http://n2.nabble.com/WCS-WMS-accuracy-tests-tp4127002p4148407.html Sent from the OSGeo Discuss mailing list archive at Nabble.com. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Hi all, I've finished my tests. The conclusion: Geoserver has a bug which offsets all the results by half a pixel, this is a known issue with the definition of the location of a pixel. Added to this there’s the no-data border which appears with non-native, non-multiple requests. I presume that will be gone once the pixel issue is resolved. Mapserver doesn’t offset the data unless it is physically impossible (non-native, non-multiple resolutions, extents which don’t snap to source data) but produces a multi-band geotiff where the source data is single band. Deegree has a bug which offsets some of the results, but I don’t know what causes it and although it is resolution-related I don’t see a pattern. It also produces a multi-band geotiff instead of a single band. The full report can be found at: http://blog.minst.net/2009/12/09/perceived-wcs-inaccuracy (slow site warning) The issue for Geoserver can be found at http://jira.codehaus.org/browse/GEOS-3702 The issue for Deegree can be found at http://wald.intevation.org/tracker/index.php?func=detailaid=1216group_id=27atid=212 For mapserver I didn't file a bug since I'm not entirely sure if the GeoTiff multi-band image is me or mapserver and I didn't inverstigate it any further. If there are any questions or remarks let me know regards, Steven On Dec 8, 2009, at 9:31 AM, Judit Mays wrote: Hello Steven, the deegree crowd would also be interested in a description of your test cases and the results. If you could send an email either here or, preferably, to the deegree developer list [1], this would be much appreciated. I talked to one of the main deegree WMS developers and he told me that deegree-wms passes all the OGC CITE tests of CITE 1.3.0, and that there are specific tests which check whether the returned tiff contains the expected pixels. So it would indeed be interesting to see, what is different in your tests to cause the offset. Kind regards, Judit [1] deegree-de...@lists.sourceforge.net | register at: https://lists.sourceforge.net/lists/listinfo/deegree-devel Steven M. Ottens schrieb: On Dec 7, 2009, at 7:04 PM, Frank Warmerdam wrote: Steven M. Ottens wrote: On Dec 7, 2009, at 6:48 PM, Frank Warmerdam wrote: Steven M. Ottens wrote: Hi all, Working with Geoserver as a WCS we discovered that requesting a GeoTIFF in the same projection as the original GeoTIFF produces a shifted dataset. (http://jira.codehaus.org/browse/GEOS-3702) The shift is small, less than one pixel of the original dataset, but with a coarse dataset of 100m/pixel it can be 70meters. The Geoserver people are aware of the problem and at some point in time will fix it I'm sure, but it prompted me to test other OSS WCS servers (mapserver and deegree). Both of them showed a shift of the data as well. Deegree has about the same error as Geoserver, while Mapserver does a better job but is still off. I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? Steven, I would appreciate your filing a detailed ticket on this issue against MapServer. Please be specific about the exact request made, provide the data and mapfile, and explain why you think the results are wrong. Will do once the tests are completed. Currently we overlay the original GeoTiff with the result of the request in QGIS. Other ways of testing are welcome. (I was thinking gdal-info output, overlay in uDig and ArcMap to rule out bias of QGIS) Steve, Are you requesting the data at greater than the natural resolution of the image? Is it the DescribeCoverage extent details that are wrong? If you request the imagery supersampled (at higher resolution than the underlying image) then there is a known issue with MapServer that can be fixed by setting adding the following line to the LAYER at some cost in processing speed: I will test both the same resolution and a greater resolution to be sure. Currently we request a greater resolution since that's what we need. PROCESSING RESAMPLE=NEAREST I discovered that already and included it in my mapfile. The trouble is that the image from Mapserver (and the other services) is shifted to the South East. I only did a quick test before the office closed so the exact shift is still to be determined, but it was noticeable smaller than with Geoserver and Deegree. For Geoserver we tested it both by defining a resolution of the output image and with a width and height with the same BBOX. For Mapserver I only tried the resolution request (resx=#resy=#) If that is the issue then a ticket might still be appropriate, but I will take a different approach which is to force use of the more precise resampler when any raster draw request is made at supersampled resolution. Best regards, -- ---+-- I set the
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Steven M. Ottens wrote: Hi all, I've finished my tests. The conclusion: Geoserver has a bug which offsets all the results by half a pixel, this is a known issue with the definition of the location of a pixel. Added to this there’s the no-data border which appears with non-native, non-multiple requests. I presume that will be gone once the pixel issue is resolved. Ah hem, are you sure it's correct to call it a bug? My impression is that we are respecting the OGC specs to the letter and that, as it often happens, the real world is actually working differently, but I need to double check with Simone that dealt with this issue more in detail Cheers Andrea ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Steven M. Ottens wrote: Mapserver doesn’t offset the data unless it is physically impossible (non-native, non-multiple resolutions, extents which don’t snap to source data) but produces a multi-band geotiff where the source data is single band. Steven, Thanks for the excellent post. I'd be interested in following up on the singleband / multiband issue with MapServer WCS when you have time. I vaguely recall there being an issue with this at one point but I thought it was solved quite a while ago. So if it persists in 5.6.0 I'd love a chance to fix it. Andrea Aime wrote: Steven M. Ottens wrote: Hi all, I've finished my tests. The conclusion: Geoserver has a bug which offsets all the results by half a pixel, this is a known issue with the definition of the location of a pixel. Added to this there’s the no-data border which appears with non-native, non-multiple requests. I presume that will be gone once the pixel issue is resolved. Ah hem, are you sure it's correct to call it a bug? My impression is that we are respecting the OGC specs to the letter and that, as it often happens, the real world is actually working differently, but I need to double check with Simone that dealt with this issue more in detail Andrea / Simone, I have set myself to watch GEOS-3702. I'd like to be sure we all reach the same understanding of the specification. 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 ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Steven M. Ottens wrote: On Dec 9, 2009, at 3:44 PM, Frank Warmerdam wrote: Steven M. Ottens wrote: Mapserver doesn’t offset the data unless it is physically impossible (non-native, non-multiple resolutions, extents which don’t snap to source data) but produces a multi-band geotiff where the source data is single band. Steven, Thanks for the excellent post. I'd be interested in following up on the singleband / multiband issue with MapServer WCS when you have time. I vaguely recall there being an issue with this at one point but I thought it was solved quite a while ago. So if it persists in 5.6.0 I'd love a chance to fix it. I'm happy to help, the map file and source data can be found here: http://dl.dropbox.com/u/175548/data.zip and the server itself is accessible through http://research.geodan.nl/cgi-bin/mapserver56/mapserv.exe?map=maps/corine.map; If you need anything else let me know. Steven, I believe you would want to change this: OUTPUTFORMAT NAME GTiff DRIVER GDAL/GTiff MIMETYPE image/tiff IMAGEMODE RGB EXTENSION tif END to: OUTPUTFORMAT NAME GTiff DRIVER GDAL/GTiff MIMETYPE image/tiff IMAGEMODE BYTE EXTENSION tif END IMAGEMODE RGB essentially tells MapServer to produce a normal 24bit RGB image result using the normal painting mechanisms. Using IMAGEMODE BYTE tells mapserver to produce a BYTE raster result and incidentally will match the number of bands to the source image. BYTE (and INT16 and FLOAT) are often more appropriate for WCS when you want to preserve original pixel values exactly rather than visually. 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 ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
On Dec 9, 2009, at 6:02 PM, Frank Warmerdam wrote: Steven, I believe you would want to change this: OUTPUTFORMAT NAME GTiff DRIVER GDAL/GTiff MIMETYPE image/tiff IMAGEMODE RGB EXTENSION tif END to: OUTPUTFORMAT NAME GTiff DRIVER GDAL/GTiff MIMETYPE image/tiff IMAGEMODE BYTE EXTENSION tif END Thanks, I figured it was a configuration issue, but didn't look into it, was busy testing something else ;) The change does fix the 'problem' and now I do get single band images. Regards, Steven ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
Re: [OSGeo-Discuss] WCS/WMS accuracy tests?
Hello Steven, the deegree crowd would also be interested in a description of your test cases and the results. If you could send an email either here or, preferably, to the deegree developer list [1], this would be much appreciated. I talked to one of the main deegree WMS developers and he told me that deegree-wms passes all the OGC CITE tests of CITE 1.3.0, and that there are specific tests which check whether the returned tiff contains the expected pixels. So it would indeed be interesting to see, what is different in your tests to cause the offset. Kind regards, Judit [1] deegree-de...@lists.sourceforge.net | register at: https://lists.sourceforge.net/lists/listinfo/deegree-devel Steven M. Ottens schrieb: On Dec 7, 2009, at 7:04 PM, Frank Warmerdam wrote: Steven M. Ottens wrote: On Dec 7, 2009, at 6:48 PM, Frank Warmerdam wrote: Steven M. Ottens wrote: Hi all, Working with Geoserver as a WCS we discovered that requesting a GeoTIFF in the same projection as the original GeoTIFF produces a shifted dataset. (http://jira.codehaus.org/browse/GEOS-3702) The shift is small, less than one pixel of the original dataset, but with a coarse dataset of 100m/pixel it can be 70meters. The Geoserver people are aware of the problem and at some point in time will fix it I'm sure, but it prompted me to test other OSS WCS servers (mapserver and deegree). Both of them showed a shift of the data as well. Deegree has about the same error as Geoserver, while Mapserver does a better job but is still off. I know there have been speed tests between different WMS services, but I'm wondering has there been any data-quality/accuracy test been done between WMS and/or WCS services? Steven, I would appreciate your filing a detailed ticket on this issue against MapServer. Please be specific about the exact request made, provide the data and mapfile, and explain why you think the results are wrong. Will do once the tests are completed. Currently we overlay the original GeoTiff with the result of the request in QGIS. Other ways of testing are welcome. (I was thinking gdal-info output, overlay in uDig and ArcMap to rule out bias of QGIS) Steve, Are you requesting the data at greater than the natural resolution of the image? Is it the DescribeCoverage extent details that are wrong? If you request the imagery supersampled (at higher resolution than the underlying image) then there is a known issue with MapServer that can be fixed by setting adding the following line to the LAYER at some cost in processing speed: I will test both the same resolution and a greater resolution to be sure. Currently we request a greater resolution since that's what we need. PROCESSING RESAMPLE=NEAREST I discovered that already and included it in my mapfile. The trouble is that the image from Mapserver (and the other services) is shifted to the South East. I only did a quick test before the office closed so the exact shift is still to be determined, but it was noticeable smaller than with Geoserver and Deegree. For Geoserver we tested it both by defining a resolution of the output image and with a width and height with the same BBOX. For Mapserver I only tried the resolution request (resx=#resy=#) If that is the issue then a ticket might still be appropriate, but I will take a different approach which is to force use of the more precise resampler when any raster draw request is made at supersampled resolution. 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 -- Judit Mays l a t / l o n GmbH Aennchenstrasse 19 53177 Bonn, Germany phone ++49 +228 18496-0 fax ++49 +228 18496-29 http://www.lat-lon.dehttp://www.deegree.org signature.asc Description: OpenPGP digital signature ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
