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I got some great advice on how to transform a geoPDF to a geoTIF on this post, which used the available downloads from this site. I would like to take it a little further and not only convert, but remove the border of historical USGS maps in order to be able to tile them in QGIS. Being a basic GIS user, I get lost in the "coding" involved to implement these practices.

How can I convert and crop historical USGS maps so they can be tiled in QGIS?

Thank you in advance for the insight.

So I am attempting to do this again, it has been awhile. I made it through the steps and I get a cropped quad that has back areas along the edges. I don't believe this happened when I did this in the past. enter image description here

  • There is no question here. please re-phrase into a question. – Brad Nesom Oct 21 '13 at 14:41
  • The black borders are really no color, the tiles should be transparent there. You get those artefacts if you reproject a rectangle into another projection. You can try -dstalpha or -dstnodata in gdalwarp to make the borders white. Better ask another question about it if the problem remains. – AndreJ Feb 28 '14 at 12:34
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Here are the steps how I managed to clip your Geopdf from the last question:

  • Read the imprinted border coordinates clockwise from the map and put them into a text file like this:
Nr;WKT
1;POLYGON((-74.25 41.75, -74.0 41.75, -74.0 41.5, -74.25 41.5, -74.25 41.75))
  • Load the text file as text delimited file, with ; as delimiter and NAD27 EPSG:4267 as CRS. The polygon should match with the map canvas, leaving out the border.

  • Save the polygon into the same CRS as the tif file. This is a poly projection, and you find it in the user defined CRS list. Add the shapefile to the canvas.

`+proj=poly +lat_0=41.5 +lon_0=-74.125 +x_0=0 +y_0=0 +ellps=clrk66 +nadgrids=@conus,@alaska,@ntv2_0.gsb,@ntv1_can.dat +units=m +no_defs`
  • Clip the tif on the polygon file with Raster -> Extraction -> Clipper

The command line should look something like

`gdalwarp -q -cutline D:/Karten/shp/Länder/USA/Newburg-border.shp -crop_to_cutline -of GTiff D:/Karten/gdal/gdalwarp/Newburg.tif D:/Karten/shp/Länder/USA/Newburg-clip`

This is what I got: enter image description here

  • I did what you said and it worked like a charm. I am attempting to do the same thing from the Schunemunk geo.PDF using the following code, but I get an error. – LandArch Oct 28 '13 at 13:09
  • : Nr;WKT 1;POLYGON((-74.25 41.5, -74.0 41.5, -74.0 41.5, -74.0 41.25, -74.25 41.25)) – LandArch Oct 28 '13 at 13:12
  • In your data, the second and third point are identical. For a polygon, the first and last should be identical. – AndreJ Oct 28 '13 at 13:18
  • I guess it helps if you close the polyline, thanks. – LandArch Oct 28 '13 at 15:12
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use arcgis (raster calculator) http://www.brocku.ca/maplibrary/procedures/merge_grid/mergeGRID.htm

We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.

  • 2
    Advertising Arcgis methods when the question asks for QGIS has only limited use. – AndreJ Feb 3 '15 at 10:19
  • and is likely to be downvoted. – PolyGeo Feb 3 '15 at 10:23

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