[notes] Converting MRSID to GeoTIFF using GDAL in Mac OS 10.6 (Snow Leopard)

Just found out how to convert MrSID files (from NZ geology) to other formats using GDAL.

  • Followed instructions here: http://www.photo-mark.com/notes/2008/nov/12/converting-mrsid-gis-files/
  • Needed most recent version of GDAL with frameworks (1.8 Complete): http://www.kyngchaos.com/software/frameworks
  • Had to change command to “/Library/Frameworks/GDAL.framework/Versions/Current/Programs/gdal_translate -of PNG /Users/Matt/Desktop/whangarei/inputmap.sid /Users/Matt/Desktop/whangarei/outputmap.png”
  • That makes an image file, but I think I’ll convert to geotiff for GIS:
    • /Library/Frameworks/GDAL.framework/Versions/Current/Programs/gdal_translate /Users/Matt/Desktop/whangarei/inputmap.sid /Users/Matt/Desktop/whangarei/outputmap.tif
  • Map source: http://www.gns.cri.nz/Home/Our-Science/Energy-Resources/Geological-Mapping/Geological-Maps/1-250-000-QMAP/Map-downloads
  • Map coordinate system: New Zealand Map Grid (Geodetic Datum 1949)
  • gdal_translate man: http://www.gdal.org/gdal_translate.html

Comment on “How Bicycling Connects Us to a Healthier Community and Stronger Economy”

I submitted this comment this morning, but it hasn’t been approved yet. Hopefully it will be.

In response to How Bicycling Connects Us to a Healthier Community and Stronger Economy by Tyler Pell, I had these thoughts on how to improve these arguments:

“I think these are good points, but in the interest of helping to win over people who are stuck in a car monoculture, I’d suggest two things.

First, you should point out exactly why “keeping cars off the road” is good for community. It removes congestion, reduces noise, allows people to stop and chat while they are commuting, all of which strengthen the ties between people who live in the community.

Second, you should move all the environmental issues to a separate section. There are more than enough reasons for people to ride bicycles without shoving “the environment” or “climate change” down people’s throats. Note that I agree completely that it’s good for the environment to commute by bicycle, but I know it’s a sensitive subject with some people; if you give these people other reasons that they can personally get behind as human beings or consumers, you have a better chance at getting them into cycling.

Thanks for all the citations, this is a good resource overall.


I think my suggestions are meaningful because when you’re trying to debate someone, it works best to start from a common ground and work toward the point your trying to make, all the while explaining why your points make sense. “The environment” is a nonstarter for some people. “Community” is a great thing to aim for, and I think Pell did a good job expressing that. Economics is a good place to start for some people, as long as you don’t get into too much theory.

Even though I frame this as a debate, remember that anyone you’re trying to convince to commute by bicycle is a future comrade-in-arms. Even if they don’t agree to do it themselves now, they may consider it in the future after your conversation, and they may be just a bit more understanding, which is good for community as well.