<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=us-ascii" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.18812"></HEAD>
<BODY>
<DIV><SPAN class=009512717-13122011><FONT size=2 face=Arial>I am trying to
convert the historic USGS topo maps (GeoPDFs) into GeoTIFFs<SPAN
class=543185718-13122011><FONT color=#0000ff><FONT color=#000000> with
GDAL 1.8</FONT> </FONT></SPAN>. A very straightforward thing to do
is</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2 face=Arial>gdal_translate
in.pdf out.tiff</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2 face=Arial>This works fine but
the TIFF looks as if the PDF was exported at 150dpi, which is a pretty crappy
resolution. Using something else (like PDFCreator and printing to a TIFF),
the USGS GeoPDFs can be exported at higher resolutions, but then of course you
lose the georeferencing. So I have GDAL which keeps the georeferencing but
only seems to like 150dpi, and then a zillion other solutions which allow 300
dpi or 600 dpi, but have no georeferencing.</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2 face=Arial>I did try gdalwarp
-tr 5 5 for example (which would roughly be equivalent to one of these maps at
300dpi), but it is clear that it is still rendering the PDF at 150dpi and then
generating a 5-meter TIFF - looks no different really than the default output
with gdal_translate.</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV><SPAN class=009512717-13122011>
<DIV><SPAN class=009512717-13122011><FONT size=2 face=Arial>Is there some
argument that would specify the dpi at which the GeoPDF were rendered before
conversion to GeoTIFF? I don't see anything like that in the docs or the
list archives.</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><FONT size=2 face=Arial>BTW if you haven't checked out the historic topos
they are great, going back to the 1880s for Maine. What fun!</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV></SPAN><SPAN class=009512717-13122011><FONT size=2 face=Arial>My ultimate
goal is to have a seamless mosaic WMS of the old topos for
Maine.</FONT></SPAN></DIV>
<DIV><SPAN class=009512717-13122011><FONT size=2
face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left>*****************<BR><FONT size=-1><SPAN
style="FONT-FAMILY: Arial">Michael Smith</SPAN><BR><SPAN
style="FONT-FAMILY: Arial">State GIS Manager, Maine Office of GIS, Maine
OIT</SPAN><BR><SPAN style="FONT-FAMILY: Arial">Board Member, Maine
GeoLibrary</SPAN><BR><SPAN style="FONT-FAMILY: Arial">Board Member, Maine GIS
Users Group</SPAN><BR><SPAN style="FONT-FAMILY: Arial">State Rep, National
States Geographic Information Council<BR><BR></SPAN></FONT><IMG border=0
alt=icons src="icons_tiny.jpg" width=299 height=68 useMap=#iconsmap> <MAP
name=iconsmap><AREA href="http://www.maine.gov/megis" shape=rect alt=MEGIS
coords=0,0,82,67 BORDER="0"><AREA href="http://www.maine.gov/geolib"
shape=rect alt=GeoLibrary coords=83,0,132,67 BORDER="0"><AREA
href="http://www.megug.org" shape=rect alt=MEGUG coords=133,0,206,67
BORDER="0"><AREA href="http://www.nsgic.org" shape=rect alt=NSGIC
coords=207,0,298,67 BORDER="0"></MAP><BR><BR><FONT size=-2><SPAN
style="FONT-FAMILY: Arial">State House Station 174</SPAN><BR><SPAN
style="FONT-FAMILY: Arial">264 Civic Center Drive</SPAN><BR><SPAN
style="FONT-FAMILY: Arial">Augusta, ME 04333-0174</SPAN><BR><SPAN
style="FONT-FAMILY: Arial">(207) 215-5530</SPAN><BR><BR><SPAN
style="FONT-FAMILY: Arial">69</SPAN> <SUP style="FONT-FAMILY: Arial">o</SUP>
<SPAN style="FONT-FAMILY: Arial">47' 49.5"W 44</SPAN> <SUP
style="FONT-FAMILY: Arial">o</SUP> <SPAN style="FONT-FAMILY: Arial">20'
54.5"N</SPAN> </FONT><BR><BR></DIV>
<DIV> </DIV></BODY></HTML>