Hi Larry,
GDAL development branch has now a geopackage driver for vectors
http://gdal.org/ogr/drv_geopackage.html
I prepared a little test geopackage and put hit here
http://latuviitta.org/documents/GDAL_geopackage_test.gpkg
The package contains some points, multipoints, lines, multilines, polygons and
multipolygons so it should suit well for testing how to get correct WKB out of
Geopackage BLOBs.
Fastest way for getting "a first-class utility to import and export data to
geopackages" for OpenJUMP would probably go through GDAL. It has now geopackage
driver and I know a GDAL developer who can do read/write driver for the native
OpenJUMP jml-xml format in a few days. Support for many other formats would
come for the same price http://gdal.org/ogr/ogr_formats.html, Unfortunately the
price was a little bit too high for my own needs and the contract is waiting
for a bigger need or other people to share the costs.
-Jukka Rahkonen-
________________________________
Larry Reeder wrote:
> Hey Jukka,
> I just got done scanning the OGC Geopackage specification. That thing is
> huge! It sounds like OGC is positioning it as the open standard replacement
> for shapefiles or geodatabases, which is something that is really needed.
> Ideally, OJ would have a first-class utility to import and export data to
> geopackages. I don't have the time to pull that off right now, but I'll
> follow your suggestions and look at adding some support for it to the DbQuery
> plugin.
-Larry
On Fri, Jan 3, 2014 at 4:08 PM, Rahkonen Jukka
<jukka.rahko...@mmmtike.fi<mailto:jukka.rahko...@mmmtike.fi>> wrote:
Hi,
GeoPackage is a queryable datastore just like any SQLite or Spatialite DB.
Attribute queries can be done through SQL like against any other database. Here
is a brand new sample for testing
https://drive.google.com/file/d/0BzouoZCWtrv8c0pDc2NaWUdQcFk/edit?usp=sharing
I renamed the db file 'world.gpkg' into 'world.sqlite', opened it with
spatialite-gui and tested with queries like
select * from geonames
where featureclass='P'
and population>1000;
Geometries are naturately not usable in spatialite-gui because the blobs are
not spatialite blobs.
The sample db contains only points and rasters. GDAL geopackage driver is close
to ready and when it is I can create sample databases with all kind of
geometries.
Links to follow:
https://groups.google.com/forum/#!topic/spatialite-users/Z4-qBOT4TFI
http://trac.osgeo.org/gdal/ticket/5335
-Jukka Rahkonen-
________________________________
Larry Reeder wrote:
> Hey Jukka,
> Although it uses SQLlite, it sounds like GeoPackage is a data storage
> mechanism like shapefiles, more than a general queryable data store. For
> that reason, it's probably a better fit in OJ as one of the options for
> "Open", "Open File...". That said, it would probably be fun to work on, and
> I'll put that on my todo list unless someone else wants to take it. But
> first I need to get that patch for the JTS WKBReader....
-lreeder
On Tue, Dec 3, 2013 at 1:56 AM, Rahkonen Jukka
<jukka.rahko...@mmmtike.fi<mailto:jukka.rahko...@mmmtike.fi><mailto:jukka.rahko...@mmmtike.fi<mailto:jukka.rahko...@mmmtike.fi>>>
wrote:
Hi,
I started a new thread because Larry Reeder wrote " Now that cold is here, I've
got more time to stay indoors and code. "
I have a feeling that if it will be cold enough then Larry can make the plugin
to read aldo blobs from GeoPackage databases.
GeoPackage is a new OGC Standard candidate. Info about that is in
https://github.com/opengis/geopackage
and the version 0.8 is available from
https://portal.opengeospatial.org/files/?artifact_id=54838
When it comes to DB Query plugin, the GeoPackage is a SQLite database where
geometries have been stored as BLOBs. These BLOBs contain standard WKB
presentation with some headers. The binary format is described here
http://opengis.github.io/geopackage/#gpb_format
Unfortunately I could not find any public GeoPackage database sample but such
can be downloaded after registration from Luciad
http://demo.luciad.com/GeoPackage/Download.html
Luciad has also started on open source project for a geopackage library
https://bitbucket.org/luciad/libgpkg/overview
There seems to be also some GeoTools code for GeoPackages but I am not sure if
it is up to date. The binary format was changed a bit perhaps in August.
http://docs.geotools.org/latest/javadocs/org/geotools/geopkg/GeoPackage.html
What DB Query tool should do is to read the BLOB, interpret the headers and
jump to correct byte offset for reading the WKB so that it can be passed on to
JTS. I tried to read some older version of the specification version in July,
2013 and came the this conclusion:
1) Check if BLOB begins with "GPB" bytes (47 50 42). If yes, then it is a
GeoPagkage BLOB.
2) Study the fourth byte and find the envelope type from "E" bits (1, 2, and 3).
3) Skip the four srs_id bytes and based on the envelope type, either 0, 32, 48,
or 64 bytes more.
4) Here starts the WKB
Thus the first byte of WKB is either byte number 9, 41, 57, or 73.
I am not sure if this was a perfect interpretation ever of if adjustments to
the spec has changed things but I believe that logically this is close to
correct.
-Jukka Rahkonen-
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance
affects their revenue. With AppDynamics, you get 100% visibility into your
Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349351&iu=/4140/ostg.clktrk
_______________________________________________
Jump-pilot-devel mailing list
Jump-pilot-devel@lists.sourceforge.net<mailto:Jump-pilot-devel@lists.sourceforge.net><mailto:Jump-pilot-devel@lists.sourceforge.net<mailto:Jump-pilot-devel@lists.sourceforge.net>>
https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
------------------------------------------------------------------------------
Rapidly troubleshoot problems before they affect your business. Most IT
organizations don't have a clear picture of how application performance
affects their revenue. With AppDynamics, you get 100% visibility into your
Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro!
http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk
_______________________________________________
Jump-pilot-devel mailing list
Jump-pilot-devel@lists.sourceforge.net<mailto:Jump-pilot-devel@lists.sourceforge.net>
https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
------------------------------------------------------------------------------
CenturyLink Cloud: The Leader in Enterprise Cloud Services.
Learn Why More Businesses Are Choosing CenturyLink Cloud For
Critical Workloads, Development Environments & Everything In Between.
Get a Quote or Start a Free Trial Today.
http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk
_______________________________________________
Jump-pilot-devel mailing list
Jump-pilot-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
