RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
That is great. Thanks! -isl ---Original Message--- From: Michael P. Gerlek m...@lizardtech.com Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 13:59 Yes, JP2 supports signed and unsigned types of up to ~24 bits. And lots of channels (bands). And alpha masking. And arbitrary metadata blobs (geospatial and otherwise). -mpg -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Lucena, Ivan Sent: Friday, August 21, 2009 12:22 PM To: OSGeo Discussions; OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] But you can't compress data types other than byte in JPG. Can you do that in JP2K? ---Original Message--- From: Landon Blake lbl...@ksninc.com Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 12:42 Paul, I was wondering the same thing. It seems a little like choosing to drive a Honda Accord, or a Ferrari. The Ferrari is a lot faster and comes with a better looking trophy wife (or husband), but the Honda is a lot easier to fix. (Try finding an affordable Ferrari mechanic in Stockton, California.) To tie this back into our original discussion, it seems like the government should be choosing to drive a Honda Accord when it can, instead of the Ferrari. I guess you'd really have to crunch the numbers and see if the savings in bandwidth/disk space costs were really worth the compression savings that result from a proprietary compression scheme (wavelet black magic). The problem with this is a lot of the benefits that come from the Honda Accord (open image format + open compression algorithm) aren't easily calculated in dollars and cents. Still, this speaks to an important truth I have discovered in open source development: Simple is better, even when it isn't necessarily faster and smaller. I'd rather have code that I can understand, or a file format that a programmer in 20 years will understand, than a Ferrari you can't drive unless you have a PHD and did a thesis on wavelet compression. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Paul Ramsey Sent: Friday, August 21, 2009 10:36 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] So hung up on wavelets, we are. Internally tiled TIFF with JPEG compression and similarly formatted internal overviews can achieve 10:1 compression rates without noticeable image quality reductions, and as an added bonus can be decompressed a heck of a lot faster than wavelet-based formats. The wavelet stuff is k00l, in that there is no need for an overview pyramid (it's implicit in the compression math) and much higher compression rates can be achieved. But operationally, you can go a long way with the more primitive (open image format + open compression algorithm) approach. P. ___ Discuss mailing list disc...@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss Warning: Information provided via electronic media is not guaranteed against defects including translation and transmission errors. If the reader is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this information in error, please notify the sender immediately. ___ Discuss mailing list disc...@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ 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] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Hi Landon, It has been an interesting discussion, algorithms copyrights, most used formats, limitations, internal details, etc. I definitely agree that it got out of control and we should end some place but I and going to give you a quick answer. What are the limitations of Geotiff/JPEG compared with the proprietary alternatives? - It is lossy (not that JPEG itself can't be lossless. you can search for libjpeg.doc for more info). - It can't store NDVI, Temperature or any other calculated or remotely sensored data in decimal values. My sincere best regards, Ivan ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss
RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Wow. Whoddu thunk we'd spend so much time and energy trying to make big pictures smaller. Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Michael P. Gerlek Sent: Friday, August 21, 2009 9:55 AM To: OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Not a stupid question -- but it doesn't work that way. The artifacts are due to the wavelet processing of the pixels near the tile boundaries, and the boundaries have to be treated reflectively within their individual tiles (in order to keep each tile separate), which means you can sometimes see where those boundaries are. Overlapping doesn't help because the wavelet footprint spans a large width, in order to handle the lower-resolution scales. Which in turn means you need to be able reach far away parts of the image at various (some might say arbitrary) stages in the wavelet pipeline. Just trust me, it is a nontrivial problem to solve. Brighter minds than ours have spent a lot of energy on this problem -- a literature search would reveal a number of PhD theses and patents. -mpg -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Landon Blake Sent: Friday, August 21, 2009 10:45 AM To: OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File Formats andProprietaryAlgorithms[SEC=UNCLASSIFIED] MPG wrote: Tiling essentially means you can take a large file and compress pieces of it independently. This avoids having to deal with the large memory footprint issues, but it can also lead to seam-line artifacts under certain conditions. Ideally, one would prefer to have the option of compressing large images without resorting to using tiles. This is probably a stupid question, since I know absolutely nothing about image compression, but couldn't you overlap the tiles slightly to avoid the seam lines? This would obviously result in a slightly larger file size because some pixels would be compressed twice. But that might be OK if you were trying to compress a huge image. What about reading chunks of the image off disk, instead of trying to put the whole image in memory? This would be slower, but might make an impossible task possible. We run into this problem with vector datasets to. Some datasets are just to stinking BIG. One of my tasks for OpenJUMP is to write a core module that displays vector data accessed directly from disk, instead of from memory. This will be slower, but it is better than crashing the program because there isn't enough RAM. Things must be more complicated than can be described in an e-mail, because we've got people a lot smarter than me working on these problems. I am just curious. (I tried reading about wavelet compression on Wikipedia yesterday and quickly got a headache.) :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Michael P. Gerlek Sent: Friday, August 21, 2009 9:36 AM To: OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File Formats andProprietaryAlgorithms[SEC=UNCLASSIFIED] Tiling essentially means you can take a large file and compress pieces of it independently. This avoids having to deal with the large memory footprint issues, but it can also lead to seam-line artifacts under certain conditions. Ideally, one would prefer to have the option of compressing large images without resorting to using tiles. Note too that, in addition to the large image issue, many of the JP2 implementations out there are either not fully compliant or are not tuned for performance. A viable solution would need both of these. -mpg -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Chris Puttick Sent: Friday, August 21, 2009 9:37 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File Formats and ProprietaryAlgorithms[SEC=UNCLASSIFIED] Well, according to this page: http://jpeg2000.epfl.ch/ v.5.1, courtesy in part Eastman Kodak, provides complete JP2 support at the decoding side - not sure whether that covers the tiling or other geo needs, but doesn't it sound worth investigating? Chris - Christopher Schmidt crschm...@crschmidt.net wrote: On Fri, Aug 21, 2009 at 08:27:13AM -0700, Landon Blake wrote: Thanks for the information Michael. I am downloading Opticks right now. :] I also found this Java library for JP2, thought I'm not sure how complete/up-to-date it is: http://jj2000.epfl.ch/ Maybe we need a JPEG 2000 page on the OSGeo wiki. Note that JPEG 2000 support is different from JPEG 2000 support which works on geo-sized images. The tiling (or 'paging'? as Michael calls it) support that's supposed
RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Bob, Sorry to mess with discussion but if someone is suggesting the use of Geotiff with JPEG compressed as a Open File Format (copied and pasted from the thread title) I would like to remember myself and the audience obout the data type limitations. There's more in raster data than meet the eye, and that usually doesn't come in unsigned integer 8 bits. :) Regards, Ivan ---Original Message--- From: Bob Basques bob.basq...@ci.stpaul.mn.us Subject: RE: [OSGeo-Discuss] OpenFile FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 13:27 All, Can someone remind me again, are we talking about saving space, or making it easier to implement something . . . :c) I personally prefer nice simple internal pyramided tiles with indexing, about 10% extra space, and very good performance. Someone earlier in this thread spoke about some of these technologies being somewhat obsolete what with the new network and bandwidth speeds available for publishing. bobb Lucena, Ivan ivan.luc...@pmldnet.com wrote: But you can't compress data types other than byte in JPG. Can you do that in JP2K? ---Original Message--- From: Landon Blake lbl...@ksninc.com Subject: RE: [OSGeo-Discuss] Open FileFormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 12:42 Paul, I was wondering the same thing. It seems a little like choosing to drive a Honda Accord, or a Ferrari. The Ferrari is a lot faster and comes with a better looking trophy wife (or husband), but the Honda is a lot easier to fix. (Try finding an affordable Ferrari mechanic in Stockton, California.) To tie this back into our original discussion, it seems like the government should be choosing to drive a Honda Accord when it can, instead of the Ferrari. I guess you'd really have to crunch the numbers and see if the savings in bandwidth/disk space costs were really worth the compression savings that result from a proprietary compression scheme (wavelet black magic). The problem with this is a lot of the benefits that come from the Honda Accord (open image format + open compression algorithm) aren't easily calculated in dollars and cents. Still, this speaks to an important truth I have discovered in open source development: Simple is better, even when it isn't necessarily faster and smaller. I'd rather have code that I can understand, or a file format that a programmer in 20 years will understand, than a Ferrari you can't drive unless you have a PHD and did a thesis on wavelet compression. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Paul Ramsey Sent: Friday, August 21, 2009 10:36 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] So hung up on wavelets, we are. Internally tiled TIFF with JPEG compression and similarly formatted internal overviews can achieve 10:1 compression rates without noticeable image quality reductions, and as an added bonus can be decompressed a heck of a lot faster than wavelet-based formats. The wavelet stuff is k00l, in that there is no need for an overview pyramid (it's implicit in the compression math) and much higher compression rates can be achieved. But operationally, you can go a long way with the more primitive (open image format + open compression algorithm) approach. P. ___ Discuss mailing list Discuss@lists.osgeo.org [LINK: http://lists.osgeo.org/mailman/listinfo/discuss] http://lists.osgeo.org/mailman/listinfo/discuss Warning: Information provided via electronic media is not guaranteed against defects including translation and transmission errors. If the reader is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this information in error, please notify the sender immediately. ___ Discuss mailing list Discuss@lists.osgeo.org [LINK: http://lists.osgeo.org/mailman/listinfo/discuss] http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org [LINK: http://lists.osgeo.org/mailman/listinfo/discuss] http://lists.osgeo.org/mailman/listinfo/discuss ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org
RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Someone earlier in this thread spoke about some of these technologies being somewhat obsolete what with the new network and bandwidth speeds available for publishing. I think the comment was that by hiding the data behind a server, you can reduce the users' exposure to a myriad of file formats, some possibly proprietary. It's a good point. You still need to store the data on the servers, though, so the technologies themselves are by no means obsolete -- it's just a question of who has to deal with them. -mpg From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Bob Basques Sent: Friday, August 21, 2009 12:28 PM To: OSGeo Discussions; Ivan Lucena Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] All, Can someone remind me again, are we talking about saving space, or making it easier to implement something . . . :c) I personally prefer nice simple internal pyramided tiles with indexing, about 10% extra space, and very good performance. Someone earlier in this thread spoke about some of these technologies being somewhat obsolete what with the new network and bandwidth speeds available for publishing. bobb Lucena, Ivan ivan.luc...@pmldnet.com wrote: But you can't compress data types other than byte in JPG. Can you do that in JP2K? ---Original Message--- From: Landon Blake lbl...@ksninc.com Subject: RE: [OSGeo-Discuss] Open FileFormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 12:42 Paul, I was wondering the same thing. It seems a little like choosing to drive a Honda Accord, or a Ferrari. The Ferrari is a lot faster and comes with a better looking trophy wife (or husband), but the Honda is a lot easier to fix. (Try finding an affordable Ferrari mechanic in Stockton, California.) To tie this back into our original discussion, it seems like the government should be choosing to drive a Honda Accord when it can, instead of the Ferrari. I guess you'd really have to crunch the numbers and see if the savings in bandwidth/disk space costs were really worth the compression savings that result from a proprietary compression scheme (wavelet black magic). The problem with this is a lot of the benefits that come from the Honda Accord (open image format + open compression algorithm) aren't easily calculated in dollars and cents. Still, this speaks to an important truth I have discovered in open source development: Simple is better, even when it isn't necessarily faster and smaller. I'd rather have code that I can understand, or a file format that a programmer in 20 years will understand, than a Ferrari you can't drive unless you have a PHD and did a thesis on wavelet compression. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Paul Ramsey Sent: Friday, August 21, 2009 10:36 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] So hung up on wavelets, we are. Internally tiled TIFF with JPEG compression and similarly formatted internal overviews can achieve 10:1 compression rates without noticeable image quality reductions, and as an added bonus can be decompressed a heck of a lot faster than wavelet-based formats. The wavelet stuff is k00l, in that there is no need for an overview pyramid (it's implicit in the compression math) and much higher compression rates can be achieved. But operationally, you can go a long way with the more primitive (open image format + open compression algorithm) approach. P. ___ Discuss mailing list disc...@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss Warning: Information provided via electronic media is not guaranteed against defects including translation and transmission errors. If the reader is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this information in error, please notify the sender immediately. ___ Discuss mailing list disc...@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss ___ 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] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Ivan, Ignoring the danger that this thread will devolve into a discussion about different raster formats, I will ask you for some specifics. What are the limitations of Geotiff/JPEG compared with the proprietary alternatives? Maybe we need to cook up a Guide To Raster Data File Formats for Storage and Distribution of Public Data. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Lucena, Ivan Sent: Friday, August 21, 2009 11:54 AM To: Bob Basques; OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Bob, Sorry to mess with discussion but if someone is suggesting the use of Geotiff with JPEG compressed as a Open File Format (copied and pasted from the thread title) I would like to remember myself and the audience obout the data type limitations. There's more in raster data than meet the eye, and that usually doesn't come in unsigned integer 8 bits. :) Regards, Ivan ---Original Message--- From: Bob Basques bob.basq...@ci.stpaul.mn.us Subject: RE: [OSGeo-Discuss] OpenFile FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 13:27 All, Can someone remind me again, are we talking about saving space, or making it easier to implement something . . . :c) I personally prefer nice simple internal pyramided tiles with indexing, about 10% extra space, and very good performance. Someone earlier in this thread spoke about some of these technologies being somewhat obsolete what with the new network and bandwidth speeds available for publishing. bobb Lucena, Ivan ivan.luc...@pmldnet.com wrote: But you can't compress data types other than byte in JPG. Can you do that in JP2K? ---Original Message--- From: Landon Blake lbl...@ksninc.com Subject: RE: [OSGeo-Discuss] Open FileFormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 12:42 Paul, I was wondering the same thing. It seems a little like choosing to drive a Honda Accord, or a Ferrari. The Ferrari is a lot faster and comes with a better looking trophy wife (or husband), but the Honda is a lot easier to fix. (Try finding an affordable Ferrari mechanic in Stockton, California.) To tie this back into our original discussion, it seems like the government should be choosing to drive a Honda Accord when it can, instead of the Ferrari. I guess you'd really have to crunch the numbers and see if the savings in bandwidth/disk space costs were really worth the compression savings that result from a proprietary compression scheme (wavelet black magic). The problem with this is a lot of the benefits that come from the Honda Accord (open image format + open compression algorithm) aren't easily calculated in dollars and cents. Still, this speaks to an important truth I have discovered in open source development: Simple is better, even when it isn't necessarily faster and smaller. I'd rather have code that I can understand, or a file format that a programmer in 20 years will understand, than a Ferrari you can't drive unless you have a PHD and did a thesis on wavelet compression. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Paul Ramsey Sent: Friday, August 21, 2009 10:36 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] So hung up on wavelets, we are. Internally tiled TIFF with JPEG compression and similarly formatted internal overviews can achieve 10:1 compression rates without noticeable image quality reductions, and as an added bonus can be decompressed a heck of a lot faster than wavelet-based formats. The wavelet stuff is k00l, in that there is no need for an overview pyramid (it's implicit in the compression math) and much higher compression rates can be achieved. But operationally, you can go a long way with the more primitive (open image format + open compression algorithm) approach. P. ___ Discuss mailing list Discuss@lists.osgeo.org [LINK: http://lists.osgeo.org/mailman/listinfo/discuss] http://lists.osgeo.org/mailman/listinfo/discuss Warning: Information provided via electronic media is not guaranteed against defects including translation and transmission errors. If the reader is not the intended recipient, you are hereby notified
RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED]
Yes, JP2 supports signed and unsigned types of up to ~24 bits. And lots of channels (bands). And alpha masking. And arbitrary metadata blobs (geospatial and otherwise). -mpg -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Lucena, Ivan Sent: Friday, August 21, 2009 12:22 PM To: OSGeo Discussions; OSGeo Discussions Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] But you can't compress data types other than byte in JPG. Can you do that in JP2K? ---Original Message--- From: Landon Blake lbl...@ksninc.com Subject: RE: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] Sent: Aug 21 '09 12:42 Paul, I was wondering the same thing. It seems a little like choosing to drive a Honda Accord, or a Ferrari. The Ferrari is a lot faster and comes with a better looking trophy wife (or husband), but the Honda is a lot easier to fix. (Try finding an affordable Ferrari mechanic in Stockton, California.) To tie this back into our original discussion, it seems like the government should be choosing to drive a Honda Accord when it can, instead of the Ferrari. I guess you'd really have to crunch the numbers and see if the savings in bandwidth/disk space costs were really worth the compression savings that result from a proprietary compression scheme (wavelet black magic). The problem with this is a lot of the benefits that come from the Honda Accord (open image format + open compression algorithm) aren't easily calculated in dollars and cents. Still, this speaks to an important truth I have discovered in open source development: Simple is better, even when it isn't necessarily faster and smaller. I'd rather have code that I can understand, or a file format that a programmer in 20 years will understand, than a Ferrari you can't drive unless you have a PHD and did a thesis on wavelet compression. :] Landon Office Phone Number: (209) 946-0268 Cell Phone Number: (209) 992-0658 -Original Message- From: discuss-boun...@lists.osgeo.org [mailto:discuss-boun...@lists.osgeo.org] On Behalf Of Paul Ramsey Sent: Friday, August 21, 2009 10:36 AM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File FormatsandProprietaryAlgorithms[SEC=UNCLASSIFIED] So hung up on wavelets, we are. Internally tiled TIFF with JPEG compression and similarly formatted internal overviews can achieve 10:1 compression rates without noticeable image quality reductions, and as an added bonus can be decompressed a heck of a lot faster than wavelet-based formats. The wavelet stuff is k00l, in that there is no need for an overview pyramid (it's implicit in the compression math) and much higher compression rates can be achieved. But operationally, you can go a long way with the more primitive (open image format + open compression algorithm) approach. P. ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss Warning: Information provided via electronic media is not guaranteed against defects including translation and transmission errors. If the reader is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this information in error, please notify the sender immediately. ___ 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 ___ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss