On Thu, May 14, 1998 at 06:07:06PM +0000, R. Walker wrote: > > Do you have any idea how big a file a scanned two-foot by three-foot > > chart would require at 300 dpi? A quick calculation shows that to be > > 77,760,000 pixels! > > Which is why USGS has their topos distributed on CDROM, not the > web. Maybe a day will come when the internet can push a 77 meg > file for individual use, but we are a ways away from that. As I've already pointed out, such files compress quite nicely -- and using standard, publicly-available compression filters. There's no need to push 77 Mbyte files around. The web *is* the appropriate means by which to distribute these, especially since web technology can be used to produce custom topos which include/exclude specific kinds of features -- expanding and shrinking the size of the resulting data files based on user preferences. Here, play with this as an example: http://pubweb.parc.xerox.com/map/color=1/db=usa/features=alltypes/ht=0.68/lat=40.38/lon=-105.59/wd=1.36?227,169 It's Rocky Mountain National Park as seen by such a prototype-grade implementation of just such an interface. ---Rsk Rich Kulawiec rsk_at_gsp.org *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Thu May 14 1998 - 16:37:59 PDT
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