Good post Christopher. I will think about what you have said. In the meantime, I won't be using any big images. :]
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 Christopher Schmidt Sent: Thursday, August 20, 2009 2:50 PM To: OSGeo Discussions Subject: Re: [OSGeo-Discuss] Open File Formats and Proprietary Algorithms On Thu, Aug 20, 2009 at 01:57:16PM -0700, Landon Blake wrote: > MPG: > > Thanks for the clarification. > > When you said "there is today no open source implementation of JP2 that > is suitable for geo work" do you mean that there is no open source > library that can read and write JP2? If so, who is using the format? There are: 1. Several non-open source implementations (most of which cost money) which work at geo-sized JP2 images. 2. Many use cases of JPEG2000 which involve imagery at sizes that are less than geo. (This is the much more common case, in my research.) > Do you know why there hasn't been a broader adoption of JP2? I'm not sure what your definition is of "broader adoption"; many of the datasources I worked with for OAM were provided in either JP2 or MrSID formats. I would almost always go with MrSID, because I could: * Work with it easily, and for free * It was typically significantly smaller. Perhaps you're asking why there hasn't been more open source software written to handle large, highly compressed JP2 images better -- to which I would point out that there isn't *any* format that has good open source support for large, highly compressed images. (gzipped TIFFs work to some extent, but don't compare to the benefits gained by JP2 or MrSID in many cases.) It's a hard problem, and -- given that the major players see the costs to 'pay to play' as being trivial (and they typically are, in the big scheme of things), not in a situation where it's likely that the people with ots of money ar ein a position to spend it on open source, rather than simply paying a smaller amount for existing non-opensource solutions. Despite the claims that 'disks are cheap and bandwidth is free', many providers *are* limited by bandwidth: MassGIS, for example, had to put in cash for a costly upgrade to their badnwidth solely due to the demand put on their servers by people downloading aerial imagery. Those funds could have gone to funding more open geodata, but instead were used to maek the data that already existed more readily available. These things *do* matter, and MrSID offers, by far, the best 'bang for the buck' for amount of data per byte of download. This applies even more at the consumer end; when you talk about consuming data, MrSID is even *more* user-friendly, because the users (who have limited bandwidth) are able to open it more easily. Additionally, many viewers which include MrSID support are able to display larger images -- due to the MrSID library -- than they would be by opening the entire image in RAM or something similar. Many of my friends have used MrSID for looking at thigns like Shakespear's Folios, because tools like IfranView include it by default, and the tool "Just Works" better than anything else. I believe that the important things in terms of delivering public content to users are: * License -- Are they allowed to do what they want with it? * Ease of use -- Is it *possible* For them to do what they want with it, including downloading it in the first place? * Openness -- Can they do what htey want with it with free/open tools? If the formwer two are true, then the latter -- openness -- can be handled by third parties. Imagine that you have two options: * Data provided online, for users to download, in MrSID * Data provided on CDs, for users to have shipped to them, in GeoTIFF (The latter will almost always have a non-trivial fee, because it involves person time, but ignore that for the time being.) If these are your options -- and this *is* the case for a non-zero number of imagery providers -- which one would you prefer to use? Best Regards, -- Christopher Schmidt Web Developer _______________________________________________ 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