Archive for April, 2009

Open Source GIS – gdal2tiles

April 24, 2009

I’ve been starting to try to wrap my head around Open Source GIS tools lately, thinking about how we can use them for our projects.  In this process, I’ve done a decent amount of research, lots of downloading and installing, troubleshooting installs, and figuring out how all of these puzzle pieces fit together.  I come from a liberal arts education background and have always loved GIS because of its combination of science and art (heavy on the art).  So, naturally, the past couple of weeks have been a whirlwind of understanding, black boxes of mystery have slowly opened up and revealed themselves.  Within one of these boxes was the gdal2tiles tool from the OSGeo4W install.  It quickly and easily takes large georeferenced images (jpg, png, tif, etc) and chops them up into manageable tile sizes at standard on-line mapping zoom levels.  So instead of drawing and re-drawing a 50mb image of the Bay Area every time you pan to a new location , this allows you to draw small, seamless tiles, pieces of the whole image as you pan around.  My test here is a 10-meter hillshade of the SF Bay Area at seven different zoom levels.  Lots to build off of, lots of ideas going now, steamrolling ahead into the OS Geo world.

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