I needed to convert GeoPDF files to GeoTIFF. I'm not command-line savvy. So I was hesitant to try this. When the gdal_translate command failed no matter what I tried, I nearly gave up. (I can just screen-shot the PDFs. Right!)
But I kept digging. I found that not all GDAL installs support PDF. I had to get a specific set of GDAL binaries for Windows. Here's how and why:
I'm doing volunteer/non-profit work to publish map services that show georeferenced map layers for historic maps of Caroline County, Maryland. I'm using MapTiler, Tileserver, QGIS, and ArcGIS Online for low-cost production and publishing. Recent products are:
- 1875 and 1897 county and towns via AGOL and
- 1897 county in OpenLayers.
Next task is to publish similar services and maps from the USGS Topo GeoPDFs. I need to convert the GeoPDFs to GeoTIFF in order to publish the tiles as a service. (Esri has done this already. But only for paying customers.)
I found a tutorial for using GDAL's gdaltranslate utility. After installing GDAL and cursing my way through the godawful Windows command line window, I kept getting GDAL errors. GDAL wasn't recognizing the PDF format.
Why not? I was following the tutorial steps exactly. I checked forums and found that GDAL has PDF support in some releases but not in others -- it was working for Ubuntu installs, but not for all Windows installs. The tutorial used the Ubuntu installer. I had used the OSGeo4W installer for GDAL. That one does not include PDF support. Gotta love opensource.
I found a pointer to GDAL binaries I needed at gisinternals.com. I downloaded the zipfile with the files that are right for my Windows system. Simply unzipped the file in a folder. Then ran the SDKShell.bat file. No need to install anything. That worked for me. Gotta love opensource.
The NOAA scanned t-sheets are a great resource for historical coastal maps. geotiffs/Google Earth overlays/reports:
ReplyDeletehttp://specialprojects.nos.noaa.gov/tools/shorelinesurvey.html
G-Raster does this conversion after you pay the $5 registration charge.
ReplyDeletehttp://moagu.com/?page_id=155
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DeleteWish I had known. Thanks for the tip.
Delete>> similar services and maps from the USGS Topo GeoPDFs...
ReplyDeleteThis link is for historical USGS topo maps only. For the current USGS map series, see http://nationalmap.gov/ustopo/ and http://www.usgs.gov/faq/categories/9797. For USGS info on GeoPDF to GeoTIFF, see http://www.usgs.gov/faq/categories/9797/3704
Thanks for pointing this out.
ReplyDelete