Re: [gdal-dev] extract vector/raster data from GeoPDF
Interesting. I downloaded it with Firefox, opened it in Acrobat 9, but it doesn't recognize it as a GeoPDF. Hmmm... Joaquim Luis wrote: Brent Fraser wrote: Since the TerraGo way has been superceded by the Adobe/ISO way (thank goodness!), it makes it easier to identify the reference system definition in GDAL, so there may be some hope for GDAL and GeoPDF. Still on this matter, the GeoPDF http://www.terragotech.com/blog/quada.pdf written in the Adobe way is not recognized as a GeoPDF by my Acrobat with the TerraGo Toolbar and it crashes Chrome when trying to download it!!! ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
User error. I had to turn on the Tools - Analysis - Geospatial Location Tool to get the scrolling Lat/Lon. Brent Fraser wrote: Interesting. I downloaded it with Firefox, opened it in Acrobat 9, but it doesn't recognize it as a GeoPDF. Hmmm... Joaquim Luis wrote: Brent Fraser wrote: Since the TerraGo way has been superceded by the Adobe/ISO way (thank goodness!), it makes it easier to identify the reference system definition in GDAL, so there may be some hope for GDAL and GeoPDF. Still on this matter, the GeoPDF http://www.terragotech.com/blog/quada.pdf written in the Adobe way is not recognized as a GeoPDF by my Acrobat with the TerraGo Toolbar and it crashes Chrome when trying to download it!!! ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Brent Fraser wrote: User error. I had to turn on the Tools - Analysis - Geospatial Location Tool to get the scrolling Lat/Lon. That's right, thanks Joaquim ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Joaquim, Doing the format conversion from .ps to pdf is one thing (and there are several ways to do it), but embedding the georeferencing in the PDF to make it a GeoPDF is the interesting bit. I haven't found any open source project capable of do that. Or even capable of writing the PDF elements (e.g. Frames) necessary for writing the GeoPDF information. But I remain hopeful... Brent Joaquim Luis wrote: Brent Fraser wrote: I see the example calculation of the transformation matrix, and a statement I created a GeoPDF by running the Postscript file through Ghostscript to create a Postscript file that looks like this But I don't see where the georeferencing is written into PDF to make it a GeoPDF. Is it a Ghostscript command line? Brent, One only has to convert it to pdf using ghostscript. I did it with GMT's ps2raster, like that ps2raster quad.ps -Tf -A Joaquim Luis Brent Klokan Petr Přidal wrote: Hi, There is a great blog post (and the linked worked example post with details): http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html It shows you how to create geopdf via GhostScript - so there is already a practical open-source example how to encode the georeference into the PDF/PS according the OGC standard - for use in Acrobat Reader. To add support for such tag in MapServer, which generates pdf dynamicaly via pdflib, should not be totally problematic. Decoding is not as hard either, there are nice libraries like poppler (http://poppler.freedesktop.org/), which allows you to parse vectors (and convert them to SVG for example) or rasterize the PDF files (into TIFF,...) via Cairo. The work is in assigning correct geographic coordinates to the coordinate system internally used in PDF files and especially write the bridge to the outside world (with GDAL/OGR). I am afraid that authors of the GeoPDF standard would not like this, as it seems that the idea of GeoPDF is see it in the Acrobat, print it, but that's all. At least I think so, because they discontinued their Geopdf2geotiff product and all the conversion tools are just one way - into GeoPDF. Please correct me... Anyway, in this moment you can quite easily use utility like pdfimages to extract full quality image tiles from any GeoPDF (like those from USGS) and merge it based on their location in PDF into one GDAL file via VRT (gdalbuildvrt) with a bit of hacking. This is what I did for my favorite USGS DRG of Grand Canyon ;-). Look at: http://klokan.mzk.cz/~klokan/geopdf/ - soon I will update the MapTiler.org overlay examples... Unfortunately all PDF parsing libraries I know are GPL, and that means we can't use them for the gdal driver - because of the license issues. But to create a GPL utility for converting GeoPDF to anything what GDAL/OGR supports should be OK. Poppler can be the best base of such GDAL-based utility for reading/rasterizing of the GeoPDF files. Now just find a sponsor and time to make it ;-). Best, Klokan Petr Pridal ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Brent,
I was also digging a bit on this matter. It's true that the blogger only opens
our appetite as there is no more details on how to do it generally. I mean, for
UTM maps it has become fairly obvious how one can do it. The relevant part in
the
PS file is
[ {ThisPage}
/LGIDict
/Description Title
/CTM [(35.28267) (0) (0) (35.28267) (205188.64) (3207094.8)]
/Projection
/Description (WGS 84 UTM 16N)
/ProjectionType (TC)
/Datum (WGE)
/CentralMeridian (-87.0)
/OriginLatitude (0.0)
/FalseEasting (50.0)
/FalseNorthing (0.0)
/ScaleFactor (0.999600)
/Type /Projection
/Type /LGIDict
/Version (2.1)
/PUT pdfmark
However, there is no more info on how to program in this TerraGo way
A next post shads a bit more lite on the matter.
http://geopdf.blogspot.com/2009/02/geopdf-and-geops-with-adobe-style.html
As you can see in the quada.ps file there is an alternative Adobe way,
which encodes the referencing as
% embed georegistation info
[ {ThisPage}
/VP [
/Type /Viewport
/BBox[0 0 dh dv]
/Name Title
/Measure
/Type /Measure
/Subtype /GEO
/Bounds[0 0 0 1 1 1 1 0]
/GPTS[29.0 -90.0 30.0 -90.0 30.0 -89.0 29.0 -89.0]
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136 0.957432
0.022122]
/GCS
/Type /PROJCS
/WKT
(PROJCS[WGS_1984_UTM_Zone_16N,GEOGCS[GCS_WGS_1984,DATUM[D_WGS_1984,SPHEROID[WGS_1984,6378137,298.257223563]],PRIMEM[Greenwich,0],UNIT[Degree,0.017453292519943295]],PROJECTION[Transverse_Mercator],PARAMETER[latitude_of_origin,0],PARAMETER[central_meridian,-87],PARAMETER[scale_factor,0.9996],PARAMETER[false_easting,50],PARAMETER[false_northing,0],UNIT[Meter,1]])
]
/PUT pdfmark
Now this is more familiar, except for the
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136 0.957432 0.022122]
part that, contrary to the promise has not been explained where it comes from.
I think I could implement the first encoding type in GMT's ps2raster (if I knew
all the specs)
Second type would be even easier ... if we had a way to translate the GMT
projection syntax into
WKT, which we don't.
Joaquim
Joaquim,
Doing the format conversion from .ps to pdf is one thing (and there
are several ways to do it), but embedding the georeferencing in the PDF
to make it a GeoPDF is the interesting bit. I haven't found any open
source project capable of do that. Or even capable of writing the PDF
elements (e.g. Frames) necessary for writing the GeoPDF information.
But I remain hopeful...
Brent
Joaquim Luis wrote:
Brent Fraser wrote:
I see the example calculation of the transformation matrix, and a
statement I created a GeoPDF by running the Postscript file through
Ghostscript to create a Postscript file that looks like this
But I don't see where the georeferencing is written into PDF to make
it a GeoPDF. Is it a Ghostscript command line?
Brent,
One only has to convert it to pdf using ghostscript.
I did it with GMT's ps2raster, like that
ps2raster quad.ps -Tf -A
Joaquim Luis
Brent
Klokan Petr Přidal wrote:
Hi,
There is a great blog post (and the linked worked example post
with details):
http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html
It shows you how to create geopdf via GhostScript - so there is
already a practical open-source example how to encode the georeference
into the PDF/PS according the OGC standard - for use in Acrobat
Reader. To add support for such tag in MapServer, which generates pdf
dynamicaly via pdflib, should not be totally problematic.
Decoding is not as hard either, there are nice libraries like poppler
(http://poppler.freedesktop.org/), which allows you to parse vectors
(and convert them to SVG for example) or rasterize the PDF files (into
TIFF,...) via Cairo.
The work is in assigning correct geographic coordinates to the
coordinate system internally used in PDF files and especially write
the bridge to the outside world (with GDAL/OGR).
I am afraid that authors of the GeoPDF standard would not like this,
as it seems that the idea of GeoPDF is see it in the Acrobat, print
it, but that's all. At least I think so, because they discontinued
their Geopdf2geotiff product and all the conversion tools are just one
way - into GeoPDF. Please correct me...
Anyway, in this moment you can quite easily use utility like
pdfimages to extract full quality image tiles from any GeoPDF (like
those from USGS) and merge it based on their location in PDF into one
GDAL file via VRT (gdalbuildvrt) with a bit of hacking. This is what I
did for my favorite USGS DRG of Grand Canyon ;-).
Look at: http://klokan.mzk.cz/~klokan/geopdf/ - soon I will update the
MapTiler.org overlay examples...
Unfortunately all PDF parsing libraries I know are GPL, and that means
we can't use them for the gdal driver - because of the license issues.
But to create a GPL utility for converting GeoPDF to anything what
GDAL/OGR supports should be
Re: [gdal-dev] extract vector/raster data from GeoPDF
A bit of googling determines that the 'Adobe way' structure, together with its
elements, is defined in the ISO PDF definition - ISO 32000-1 (2008).
Looking at this with a PostScript Developer hat, the /LPTS has to be associated
with scaling / transforming the GPTS coordinates to the page coordinate system.
There is a need to refer to the standard!
Best wishes,
Peter
Joaquim Luis wrote:
Brent,
I was also digging a bit on this matter. It's true that the blogger only
opens
our appetite as there is no more details on how to do it generally. I
mean, for
UTM maps it has become fairly obvious how one can do it. The relevant
part in the
PS file is
[ {ThisPage}
/LGIDict
/Description Title
/CTM [(35.28267) (0) (0) (35.28267) (205188.64) (3207094.8)]
/Projection
/Description (WGS 84 UTM 16N)
/ProjectionType (TC)
/Datum (WGE)
/CentralMeridian (-87.0)
/OriginLatitude (0.0)
/FalseEasting (50.0)
/FalseNorthing (0.0)
/ScaleFactor (0.999600)
/Type /Projection
/Type /LGIDict
/Version (2.1)
/PUT pdfmark
However, there is no more info on how to program in this TerraGo way
A next post shads a bit more lite on the matter.
http://geopdf.blogspot.com/2009/02/geopdf-and-geops-with-adobe-style.html
As you can see in the quada.ps file there is an alternative Adobe way,
which encodes the referencing as
% embed georegistation info
[ {ThisPage}
/VP [
/Type /Viewport
/BBox[0 0 dh dv]
/Name Title
/Measure
/Type /Measure
/Subtype /GEO
/Bounds[0 0 0 1 1 1 1 0]
/GPTS[29.0 -90.0 30.0 -90.0 30.0 -89.0 29.0 -89.0]
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136
0.957432 0.022122]
/GCS
/Type /PROJCS
/WKT
(PROJCS[WGS_1984_UTM_Zone_16N,GEOGCS[GCS_WGS_1984,DATUM[D_WGS_1984,SPHEROID[WGS_1984,6378137,298.257223563]],PRIMEM[Greenwich,0],UNIT[Degree,0.017453292519943295]],PROJECTION[Transverse_Mercator],PARAMETER[latitude_of_origin,0],PARAMETER[central_meridian,-87],PARAMETER[scale_factor,0.9996],PARAMETER[false_easting,50],PARAMETER[false_northing,0],UNIT[Meter,1]])
]
/PUT pdfmark
Now this is more familiar, except for the
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136 0.957432
0.022122]
part that, contrary to the promise has not been explained where it comes
from.
I think I could implement the first encoding type in GMT's ps2raster (if
I knew all the specs)
Second type would be even easier ... if we had a way to translate the
GMT projection syntax into
WKT, which we don't.
Joaquim
Joaquim,
Doing the format conversion from .ps to pdf is one thing (and there
are several ways to do it), but embedding the georeferencing in the
PDF to make it a GeoPDF is the interesting bit. I haven't found any
open source project capable of do that. Or even capable of writing
the PDF elements (e.g. Frames) necessary for writing the GeoPDF
information. But I remain hopeful...
Brent
Joaquim Luis wrote:
Brent Fraser wrote:
I see the example calculation of the transformation matrix, and a
statement I created a GeoPDF by running the Postscript file through
Ghostscript to create a Postscript file that looks like this
But I don't see where the georeferencing is written into PDF to make
it a GeoPDF. Is it a Ghostscript command line?
Brent,
One only has to convert it to pdf using ghostscript.
I did it with GMT's ps2raster, like that
ps2raster quad.ps -Tf -A
Joaquim Luis
Brent
Klokan Petr Přidal wrote:
Hi,
There is a great blog post (and the linked worked example post
with details):
http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html
It shows you how to create geopdf via GhostScript - so there is
already a practical open-source example how to encode the georeference
into the PDF/PS according the OGC standard - for use in Acrobat
Reader. To add support for such tag in MapServer, which generates pdf
dynamicaly via pdflib, should not be totally problematic.
Decoding is not as hard either, there are nice libraries like poppler
(http://poppler.freedesktop.org/), which allows you to parse vectors
(and convert them to SVG for example) or rasterize the PDF files (into
TIFF,...) via Cairo.
The work is in assigning correct geographic coordinates to the
coordinate system internally used in PDF files and especially write
the bridge to the outside world (with GDAL/OGR).
I am afraid that authors of the GeoPDF standard would not like this,
as it seems that the idea of GeoPDF is see it in the Acrobat, print
it, but that's all. At least I think so, because they discontinued
their Geopdf2geotiff product and all the conversion tools are just one
way - into GeoPDF. Please correct me...
Anyway, in this moment you can quite easily use utility like
pdfimages to extract full quality image tiles from any GeoPDF (like
those from USGS) and merge it based on their location in PDF into one
GDAL file via VRT (gdalbuildvrt) with a bit of
Re: [gdal-dev] extract vector/raster data from GeoPDF
Peter J Halls wrote: A bit of googling determines that the 'Adobe way' structure, together with its elements, is defined in the ISO PDF definition - ISO 32000-1 (2008). Looking at this with a PostScript Developer hat, the /LPTS has to be associated with scaling / transforming the GPTS coordinates to the page coordinate system. There is a need to refer to the standard! Yes, And the TerraGo way comes possibly from this document GeoPDF Encoding Best Practice Version 2.2 http://portal.opengeospatial.org/files/?artifact_id=2 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Joaquim,
Interesting! As Peter pointed out, the LPTS tag is the transformation matrix
to go from projected coords to page coords, and is created by forming the
UTM-page coordinates tranformation (from the information in the CTM tag below)
and inverting it (there's a brief mention near the end of
http://geopdf.blogspot.com/2009/02/georegistration-worked-example.html)
Since the TerraGo way has been superceded by the Adobe/ISO way (thank
goodness!), it makes it easier to identify the reference system definition in
GDAL, so there may be some hope for GDAL and GeoPDF.
Now I need to think about my requirements for reading and writing GeoPDFs.
Write a Postscript driver for GDAL? Figure out how to write the equivalent
info into a PDF using Mapserver/Cairo? Yikes!
Thanks,
Brent
Joaquim Luis wrote:
Brent,
I was also digging a bit on this matter. It's true that the blogger only
opens
our appetite as there is no more details on how to do it generally. I
mean, for
UTM maps it has become fairly obvious how one can do it. The relevant
part in the
PS file is
[ {ThisPage}
/LGIDict
/Description Title
/CTM [(35.28267) (0) (0) (35.28267) (205188.64) (3207094.8)]
/Projection
/Description (WGS 84 UTM 16N)
/ProjectionType (TC)
/Datum (WGE)
/CentralMeridian (-87.0)
/OriginLatitude (0.0)
/FalseEasting (50.0)
/FalseNorthing (0.0)
/ScaleFactor (0.999600)
/Type /Projection
/Type /LGIDict
/Version (2.1)
/PUT pdfmark
However, there is no more info on how to program in this TerraGo way
A next post shads a bit more lite on the matter.
http://geopdf.blogspot.com/2009/02/geopdf-and-geops-with-adobe-style.html
As you can see in the quada.ps file there is an alternative Adobe way,
which encodes the referencing as
% embed georegistation info
[ {ThisPage}
/VP [
/Type /Viewport
/BBox[0 0 dh dv]
/Name Title
/Measure
/Type /Measure
/Subtype /GEO
/Bounds[0 0 0 1 1 1 1 0]
/GPTS[29.0 -90.0 30.0 -90.0 30.0 -89.0 29.0 -89.0]
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136
0.957432 0.022122]
/GCS
/Type /PROJCS
/WKT
(PROJCS[WGS_1984_UTM_Zone_16N,GEOGCS[GCS_WGS_1984,DATUM[D_WGS_1984,SPHEROID[WGS_1984,6378137,298.257223563]],PRIMEM[Greenwich,0],UNIT[Degree,0.017453292519943295]],PROJECTION[Transverse_Mercator],PARAMETER[latitude_of_origin,0],PARAMETER[central_meridian,-87],PARAMETER[scale_factor,0.9996],PARAMETER[false_easting,50],PARAMETER[false_northing,0],UNIT[Meter,1]])
]
/PUT pdfmark
Now this is more familiar, except for the
/LPTS[0.024324 0.039461 0.051689 0.978774 0.975675 0.961136 0.957432
0.022122]
part that, contrary to the promise has not been explained where it comes
from.
I think I could implement the first encoding type in GMT's ps2raster (if
I knew all the specs)
Second type would be even easier ... if we had a way to translate the
GMT projection syntax into
WKT, which we don't.
Joaquim
Joaquim,
Doing the format conversion from .ps to pdf is one thing (and there
are several ways to do it), but embedding the georeferencing in the
PDF to make it a GeoPDF is the interesting bit. I haven't found any
open source project capable of do that. Or even capable of writing
the PDF elements (e.g. Frames) necessary for writing the GeoPDF
information. But I remain hopeful...
Brent
Joaquim Luis wrote:
Brent Fraser wrote:
I see the example calculation of the transformation matrix, and a
statement I created a GeoPDF by running the Postscript file through
Ghostscript to create a Postscript file that looks like this
But I don't see where the georeferencing is written into PDF to make
it a GeoPDF. Is it a Ghostscript command line?
Brent,
One only has to convert it to pdf using ghostscript.
I did it with GMT's ps2raster, like that
ps2raster quad.ps -Tf -A
Joaquim Luis
Brent
Klokan Petr Přidal wrote:
Hi,
There is a great blog post (and the linked worked example post
with details):
http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html
It shows you how to create geopdf via GhostScript - so there is
already a practical open-source example how to encode the georeference
into the PDF/PS according the OGC standard - for use in Acrobat
Reader. To add support for such tag in MapServer, which generates pdf
dynamicaly via pdflib, should not be totally problematic.
Decoding is not as hard either, there are nice libraries like poppler
(http://poppler.freedesktop.org/), which allows you to parse vectors
(and convert them to SVG for example) or rasterize the PDF files (into
TIFF,...) via Cairo.
The work is in assigning correct geographic coordinates to the
coordinate system internally used in PDF files and especially write
the bridge to the outside world (with GDAL/OGR).
I am afraid that authors of the GeoPDF standard would not like this,
as it seems that the idea of GeoPDF is see it in the Acrobat, print
Re: [gdal-dev] extract vector/raster data from GeoPDF
Brent Fraser wrote: Joaquim, Interesting! As Peter pointed out, the LPTS tag is the transformation matrix to go from projected coords to page coords, and is created by forming the UTM-page coordinates tranformation (from the information in the CTM tag below) and inverting it (there's a brief mention near the end of http://geopdf.blogspot.com/2009/02/georegistration-worked-example.html) Since the TerraGo way has been superceded by the Adobe/ISO way (thank goodness!), it makes it easier to identify the reference system definition in GDAL, so there may be some hope for GDAL and GeoPDF. Now I need to think about my requirements for reading and writing GeoPDFs. Write a Postscript driver for GDAL? Figure out how to write the equivalent info into a PDF using Mapserver/Cairo? Yikes! Brent, I am on this list more to keep learning (as the present case) than as a core GDAL user (but I use GDAL a lot in Mirone). In fact I am much more a GMT user where I also do some development. I mentioned it before here but probably it slipped away, the GMT program ps2raster can write world files and create GeoTIFFs (from system calls to GDAL) from postscript files created by GMT. I think that it wouldn't be very hard to extend ps2raster's ability to write GeoPDFs if, as I said before, there was a way to get a WKT from a -J... GMT syntax. Anyway, it wouldn't be a GDAL solution and a write-only one so I don't know what else to tell you. Joaquim ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Brent Fraser wrote: Since the TerraGo way has been superceded by the Adobe/ISO way (thank goodness!), it makes it easier to identify the reference system definition in GDAL, so there may be some hope for GDAL and GeoPDF. Still on this matter, the GeoPDF http://www.terragotech.com/blog/quada.pdf written in the Adobe way is not recognized as a GeoPDF by my Acrobat with the TerraGo Toolbar and it crashes Chrome when trying to download it!!! ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Hi, There is a great blog post (and the linked worked example post with details): http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html It shows you how to create geopdf via GhostScript - so there is already a practical open-source example how to encode the georeference into the PDF/PS according the OGC standard - for use in Acrobat Reader. To add support for such tag in MapServer, which generates pdf dynamicaly via pdflib, should not be totally problematic. Decoding is not as hard either, there are nice libraries like poppler (http://poppler.freedesktop.org/), which allows you to parse vectors (and convert them to SVG for example) or rasterize the PDF files (into TIFF,...) via Cairo. The work is in assigning correct geographic coordinates to the coordinate system internally used in PDF files and especially write the bridge to the outside world (with GDAL/OGR). I am afraid that authors of the GeoPDF standard would not like this, as it seems that the idea of GeoPDF is see it in the Acrobat, print it, but that's all. At least I think so, because they discontinued their Geopdf2geotiff product and all the conversion tools are just one way - into GeoPDF. Please correct me... Anyway, in this moment you can quite easily use utility like pdfimages to extract full quality image tiles from any GeoPDF (like those from USGS) and merge it based on their location in PDF into one GDAL file via VRT (gdalbuildvrt) with a bit of hacking. This is what I did for my favorite USGS DRG of Grand Canyon ;-). Look at: http://klokan.mzk.cz/~klokan/geopdf/ - soon I will update the MapTiler.org overlay examples... Unfortunately all PDF parsing libraries I know are GPL, and that means we can't use them for the gdal driver - because of the license issues. But to create a GPL utility for converting GeoPDF to anything what GDAL/OGR supports should be OK. Poppler can be the best base of such GDAL-based utility for reading/rasterizing of the GeoPDF files. Now just find a sponsor and time to make it ;-). Best, Klokan Petr Pridal -- http://blog.klokan.cz/ http://www.maptiler.org/ http://www.oldmapsonline.org/ ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Klokan Petr Přidal wrote: Unfortunately all PDF parsing libraries I know are GPL, and that means we can't use them for the gdal driver - because of the license issues. But to create a GPL utility for converting GeoPDF to anything what GDAL/OGR supports should be OK. Poppler can be the best base of such GDAL-based utility for reading/rasterizing of the GeoPDF files. Folks, I would note that it is fine to use external GPL libraries for optional GDAL/OGR format drivers. It just means we won't be copying the whole source into GDAL for convenient building like we do for stuff like libtiff and that some users of GDAL will not use that driver. I'd prefer a more compatible license for supporting libraries, but it is not all that important. Best regards, -- ---+-- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush| Geospatial Programmer for Rent ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
I see the example calculation of the transformation matrix, and a statement I created a GeoPDF by running the Postscript file through Ghostscript to create a Postscript file that looks like this But I don't see where the georeferencing is written into PDF to make it a GeoPDF. Is it a Ghostscript command line? Brent Klokan Petr Přidal wrote: Hi, There is a great blog post (and the linked worked example post with details): http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html It shows you how to create geopdf via GhostScript - so there is already a practical open-source example how to encode the georeference into the PDF/PS according the OGC standard - for use in Acrobat Reader. To add support for such tag in MapServer, which generates pdf dynamicaly via pdflib, should not be totally problematic. Decoding is not as hard either, there are nice libraries like poppler (http://poppler.freedesktop.org/), which allows you to parse vectors (and convert them to SVG for example) or rasterize the PDF files (into TIFF,...) via Cairo. The work is in assigning correct geographic coordinates to the coordinate system internally used in PDF files and especially write the bridge to the outside world (with GDAL/OGR). I am afraid that authors of the GeoPDF standard would not like this, as it seems that the idea of GeoPDF is see it in the Acrobat, print it, but that's all. At least I think so, because they discontinued their Geopdf2geotiff product and all the conversion tools are just one way - into GeoPDF. Please correct me... Anyway, in this moment you can quite easily use utility like pdfimages to extract full quality image tiles from any GeoPDF (like those from USGS) and merge it based on their location in PDF into one GDAL file via VRT (gdalbuildvrt) with a bit of hacking. This is what I did for my favorite USGS DRG of Grand Canyon ;-). Look at: http://klokan.mzk.cz/~klokan/geopdf/ - soon I will update the MapTiler.org overlay examples... Unfortunately all PDF parsing libraries I know are GPL, and that means we can't use them for the gdal driver - because of the license issues. But to create a GPL utility for converting GeoPDF to anything what GDAL/OGR supports should be OK. Poppler can be the best base of such GDAL-based utility for reading/rasterizing of the GeoPDF files. Now just find a sponsor and time to make it ;-). Best, Klokan Petr Pridal ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Brent Fraser wrote: I see the example calculation of the transformation matrix, and a statement I created a GeoPDF by running the Postscript file through Ghostscript to create a Postscript file that looks like this But I don't see where the georeferencing is written into PDF to make it a GeoPDF. Is it a Ghostscript command line? Brent, One only has to convert it to pdf using ghostscript. I did it with GMT's ps2raster, like that ps2raster quad.ps -Tf -A Joaquim Luis Brent Klokan Petr Přidal wrote: Hi, There is a great blog post (and the linked worked example post with details): http://geopdf.blogspot.com/2009/02/geopdf-map-for-worked-example.html It shows you how to create geopdf via GhostScript - so there is already a practical open-source example how to encode the georeference into the PDF/PS according the OGC standard - for use in Acrobat Reader. To add support for such tag in MapServer, which generates pdf dynamicaly via pdflib, should not be totally problematic. Decoding is not as hard either, there are nice libraries like poppler (http://poppler.freedesktop.org/), which allows you to parse vectors (and convert them to SVG for example) or rasterize the PDF files (into TIFF,...) via Cairo. The work is in assigning correct geographic coordinates to the coordinate system internally used in PDF files and especially write the bridge to the outside world (with GDAL/OGR). I am afraid that authors of the GeoPDF standard would not like this, as it seems that the idea of GeoPDF is see it in the Acrobat, print it, but that's all. At least I think so, because they discontinued their Geopdf2geotiff product and all the conversion tools are just one way - into GeoPDF. Please correct me... Anyway, in this moment you can quite easily use utility like pdfimages to extract full quality image tiles from any GeoPDF (like those from USGS) and merge it based on their location in PDF into one GDAL file via VRT (gdalbuildvrt) with a bit of hacking. This is what I did for my favorite USGS DRG of Grand Canyon ;-). Look at: http://klokan.mzk.cz/~klokan/geopdf/ - soon I will update the MapTiler.org overlay examples... Unfortunately all PDF parsing libraries I know are GPL, and that means we can't use them for the gdal driver - because of the license issues. But to create a GPL utility for converting GeoPDF to anything what GDAL/OGR supports should be OK. Poppler can be the best base of such GDAL-based utility for reading/rasterizing of the GeoPDF files. Now just find a sponsor and time to make it ;-). Best, Klokan Petr Pridal ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] extract vector/raster data from GeoPDF
Keith, No talk that I'm aware of. There was a little chatter on the Geowanking list: http://geowanking.org/pipermail/geowanking_geowanking.org/2009-February/017492.html And occasionally some interest about producing PDF from Mapserver (e.g. http://lists.osgeo.org/pipermail/mapserver-users/2009-July/062035.html). I'm hoping that as GeoPDF becomes popular some funding can be found to build a GDAL/OGR driver to read it. Best Regards, Brent Fraser keith lewis wrote: Hello people, Is there any talk about developing tools in GDAL/OGR to extract raster or vector data from a GeoPDF now the 2.2 version was submitted to the OGC?? The submitted specs are for the georeferencing aspect only. ArcGIS and TerraGo tools can create a GeoPDF. The USGS offers free Geopdf that contain geospatial data. I'm sure someone will eventually release a tool. Keith ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
