Map projections and gdalwarp

I recently was working with some maps, trying to create some pretty pictures for my thesis using some of the maps by Ron Blakey. However I was too lazy to plot points on the maps by hand and I wanted to georeference the maps. I found a hand tool with QGIS that was easy enough to use, but wasn’t as precise (or as quick) as another command-line tool I found called gdal_translate. GDAL (Geospatial Data Abstraction Library) and the associated OGR comprise a number of tools and libraries that are very useful for both raster and vector geographic image manipulation. Using gdal_translate was easiest with a straight up lat/long projection, as I could just give the geographic coordinates for each of the corners and it would spit out a GeoTIFF. Thus, I was able to quickly take some of the rectangular maps and georeference and have something that I could use in QGIS. While I was playing around gdal_translate, I found another tool called gdalwarp, which has been giving me a bit more of a headache. Theoretically, gdalwarp should let me transform some of these rectangular maps into different, possibly ‘prettier’ looking maps. So far though, all I’ve managed is to make some seriously un-pretty images. I’ll post an update in a little while giving some quick instructions once I figure out how to make it all work.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s