[postgis-users] [Qgis-user] Trying to get the wktraster plugin to work

Maurício de Paulo mauricio.dev at gmail.com
Thu Dec 2 15:05:21 PST 2010 

Well, version 0.2.2, now with a schema-friendly loader and I turned off the
mode combobox.
Unfortunately, on gdal 1.7 I couldn't get the mode to work. Was anyone
successful?
Best regards,
Mauricio de Paulo


2010/12/2 Maurício de Paulo <mauricio.dev at gmail.com>

> Ok, now that i got my hands on my ubuntugis packages... Well some odd
> stuff.
> Hum... the "mode=" was added on the new driver? On 1.7 I couldn't make it
> work with it.
> I fixed andreas' sugestions and found a new bug. When I read from the table
> I should read both schema and tablename from that. And at the moment the
> plugin is not doing it. This could solve the "schema" problem. I'm going to
> fix this and release a new version.
> I don't really know if I'm going to let the mode turned on. Only if I can
> get it to work with ubuntugis' gdal version.
> Mauricio de Paulo
>
>
>>
>> On Thu, Dec 2, 2010 at 9:00 AM, Jorge Arévalo <
>> jorge.arevalo at deimos-space.com> wrote:
>>
>>> On Thu, Dec 2, 2010 at 9:29 AM, Andreas Neumann <a.neumann at carto.net>
>>> wrote:
>>> > Hi Jorge and Mauricio,
>>> >
>>> > Thank you for both of your help/feedback.
>>> >
>>> > As far as I can tell, there are two problems with the QGIS wktraster
>>> > plugin. It is currently not generating the correct connection string.
>>> > Mauricio - could you please check?
>>> >
>>> > 1. schema name is not picked up correctly from the table
>>> >
>>> > 2. reading mode is not correctly specified. My data set is tiled (read
>>> in
>>> > with the "k" parameter). I select "Read tiled raster in a table" and
>>> the
>>> > plugin selects mode "1" - but it should select mode "2", according to
>>> > Jorge and http://trac.osgeo.org/gdal/wiki/frmts_wtkraster.html.
>>> >
>>> > It seems like Mauricios plugin uses a zero-based list for the mode,
>>> while
>>> > it should use a one-based list.
>>> >
>>> > The second problem is very easy to fix by changing the line
>>> >
>>> > mode=self.dlg.ui.comboBox_2.currentIndex()
>>> > to
>>> > mode=self.dlg.ui.comboBox_2.currentIndex()+1
>>> >
>>> > and then
>>> > if (mode!=2):
>>> > to
>>> > if (mode!=3):
>>> >
>>> > The first problem is little harder to fix.
>>> >
>>> > Anyway - once I fixed the issue, the raster loads fine, but it is very,
>>> > very, very slow - too slow for real work.
>>> >
>>> > I have to admit, I did not create pyramids. Would the wktraster plugin
>>> and
>>> > the underlying driver support the pyramids? My test raster file is
>>> > 3600x4000 pixels - so it isn't really large.
>>> >
>>> > Any experiences with the pyramids with wktraster?
>>> >
>>> > Thanks a lot so far!
>>> >
>>> > Andreas
>>> >
>>>
>>> Hi Andreas, Mauricio
>>>
>>> Yes, it's possible to create pyramids with the PostGIS Raster loader,
>>> using the "-l" and "-V" options as follows:
>>>
>>> - "-l N", where N is the overview level. This option force GDAL to
>>> build overviews of the original raster, and store them as new raster
>>> tables with the name "o_<LEVEL>_<RASTER_TABLE>". <RASTER_TABLE> is the
>>> name you provide with the "-t" option. You should execute the loader
>>> one time for each pyramid level desired (-l 2, -l 4, -l 8, and so on).
>>>
>>> - "-V" forces the creation of the RASTER_OVERVIEWS table. This table
>>> stores the names of all the overviews of all the raster tables (the
>>> overviews are different tables, remember it). You should only provide
>>> this option the first time you execute the loader script. But provide
>>> it at least one time, because the GDAL driver needs this table to know
>>> if each raster table has overviews or not.
>>>
>>> Further information on raster loader here:
>>> http://trac.osgeo.org/postgis/wiki/WKTRaster/SpecificationFinal01
>>>
>>> You probably may want to test the plugin with raster overviews. I'm
>>> going to test it ASAP. Anyway, the driver performance is an important
>>> TODO task.
>>>
>>>
>>> --
>>> Jorge Arévalo
>>> Internet & Mobilty Division, DEIMOS
>>> jorge.arevalo at deimos-space.com
>>> http://mobility.grupodeimos.com/
>>> http://gis4free.wordpress.com
>>>
>>> > On Wed, December 1, 2010 10:25 pm, Jorge Arévalo wrote:
>>> >> 2010/12/1 Maurício de Paulo <mauricio.dev at gmail.com>:
>>> >>> Thanks jorge!
>>> >>> Then I figure it's a bug in the plugin. I wrote the wrong modes. I'm
>>> >>> fixing
>>> >>> and updating.
>>> >>> Hum... I'm going to wait for your responde on the parsing part. If
>>> not,
>>> >>> should I parse it on the plugin?
>>> >>> Best regards,
>>> >>> Mauricio de Paulo
>>> >>>
>>> >>
>>> >> Hi Mauricio,
>>> >>
>>> >> Just check it. If you don't provide schema name, 'public' is
>>> >> automatically selected. So, if you specify 'dtm.dtmav' as table name,
>>> >> and don't provide a 'schema' option, the driver tries to connect with
>>> >> 'public.dtm.dtmav', what is wrong.
>>> >>
>>> >> I suppose I could allow the "table=schema.table_name" syntax, but I'd
>>> >> like to keep the 'schema=' keyword to keep the schema browsing
>>> >> capability.
>>> >>
>>> >> So, it's not a plugin error. I don't think you need to change it. By
>>> >> now, just use the 'schema' keyword to specify a schema name. About the
>>> >> mode, remember that:
>>> >>
>>> >> - 'mode=1' means each row is a different raster. Report all rows as
>>> >> subdatasets
>>> >> - 'mode=2' means all rows are tiles of a bigger raster. The driver
>>> >> will 'construct' a whole raster coverage based on all tiles' extent
>>> >>
>>> >> The default mode is 'mode=1'. If you stored a tiled raster (providing
>>> >> -k option to gdal2wkraster/raster2pgsql script) and you want the
>>> >> entire raster again, provide 'mode=2' in connection string. Otherwise,
>>> >> each row will be treated as a single raster file.
>>> >>
>>> >> About PostgreSQL 9.0, I didn't test it yet, but AFAIK, it should work
>>> >> in the same way that works with PostgreSQL 8.4, for example.
>>> >>
>>> >> I'm really interested in this work. Thanks for testing the driver :-)
>>> >>
>>> >>> 2010/12/1 Jorge Arévalo <jorge.arevalo at deimos-space.com>
>>> >>>>
>>> >>>> Hello,
>>> >>>>
>>> >>>> On Wed, Dec 1, 2010 at 7:19 PM, Maurício de Paulo
>>> >>>> <mauricio.dev at gmail.com> wrote:
>>> >>>> > Hi Andreas,
>>> >>>> > As you were able to load the raster metadata i'm assuming you
>>> >>>> installed
>>> >>>> > the
>>> >>>> > wktraster sql on the database.
>>> >>>> > I've never tested myself on postgresql 9.0.
>>> >>>> > Do you have a postgresql 8.4 instance to test too? Just to be sure
>>> if
>>> >>>> > it's a
>>> >>>> > gdal incompatibility with 9.0.
>>> >>>> > Thanks for the information, I'm repassing to Jorge (GDAL's
>>> >>>> developper).
>>> >>>> > Best regards,
>>> >>>> > Mauricio de Paulo
>>> >>>> >
>>> >>>> >> Hi,
>>> >>>> >>
>>> >>>> >> I am trying to get the wktraster plugin to work.
>>> >>>> >>
>>> >>>> >> The initial connection to the db is fine. It lists all my raster
>>> >>>> >> datasets
>>> >>>> >> I have in the db.
>>> >>>> >>
>>> >>>> >> After selecting a raster (and adding the schema-name in front of
>>> the
>>> >>>> >> table-name) I hit ok and after entering the password again, I get
>>> >>>> the
>>> >>>> >> following error message:
>>> >>>> >>
>>> >>>> >> Could not load PG: dbname=uster host=localhost user=an
>>> password=xxx
>>> >>>> >> port=5432 table=dtm.dtmav mode=1
>>> >>>> >>
>>> >>>> >> In the console that started QGIS I get a warning:
>>> >>>> >>
>>> >>>> >> Warning: This version of PostgreSQL is not supported and may not
>>> >>>> work.
>>> >>>> >> ERROR 1: Error browsing database for PostGIS Raster properties
>>> >>>> >>
>>> >>>> >> Here is my Postgres/Postgis version string:
>>> >>>> >>
>>> >>>> >> "PostgreSQL 9.0.1 on x86_64-unknown-linux-gnu, compiled by GCC
>>> gcc
>>> >>>> >> (Ubuntu
>>> >>>> >> 4.4.3-4ubuntu5) 4.4.3, 64-bit"
>>> >>>> >>
>>> >>>> >> "POSTGIS="1.5.2" GEOS="3.2.0-CAPI-1.6.0" PROJ="Rel. 4.7.1, 23
>>> >>>> September
>>> >>>> >> 2009" LIBXML="2.7.6" USE_STATS"
>>> >>>> >>
>>> >>>> >> Do you have any idea what may be wrong here? Is PostgreSQL 9.0
>>> not
>>> >>>> >> supported? It works fine with my other QGIS projects ...
>>> >>>> >>
>>> >>>> >> Thanks,
>>> >>>> >> Andreas
>>> >>>> >>
>>> >>>> >> --
>>> >>>> >> Andreas Neumann
>>> >>>> >> http://www.carto.net/neumann/
>>> >>>> >> http://www.svgopen.org/
>>> >>>> >>
>>> >>>> >
>>> >>>> >
>>> >>>> > --
>>> >>>> > Mauricio de Paulo
>>> >>>> > Engenheiro Cartografo
>>> >>>> >
>>> >>>> >
>>> >>>>
>>> >>>> I assume you're using the new version of GDAL driver, commited on
>>> >>>> release 20912 (http://trac.osgeo.org/gdal/changeset/20912). The
>>> right
>>> >>>> syntax for the connection string should be
>>> >>>>
>>> >>>> PG:"dbname=uster host=localhost user=an password=xxx port=5432
>>> >>>> schema=dtm table=dtmav mode=1"
>>> >>>>
>>> >>>> instead of
>>> >>>>
>>> >>>> PG: dbname=uster host=localhost user=an password=xxx port=5432
>>> >>>> table=dtm.dtmav mode=1
>>> >>>>
>>> >>>> With this string, you'll read the rows of the table dtmav, schema
>>> dtm,
>>> >>>> as different raster files. So, the driver will report these rows as
>>> >>>> subdatasets. If you use mode=2, all the rows are considered as tiles
>>> >>>> of a bigger raster coverage.
>>> >>>>
>>> >>>> Anyway, let me check if the driver parses the
>>> >>>> "table=<schema>.<table_name>" syntax. I can't remember it.
>>> >>>>
>>> >>>> --
>>> >>>> Jorge Arévalo
>>> >>>> Internet & Mobilty Division, DEIMOS
>>> >>>> jorge.arevalo at deimos-space.com
>>> >>>> http://mobility.grupodeimos.com/
>>> >>>> http://gis4free.wordpress.com
>>> >>>
>>> >>>
>>> >>>
>>> >>> --
>>> >>> Mauricio de Paulo
>>> >>> Engenheiro Cartografo
>>> >>>
>>> >>>
>>> >>
>>> >>
>>> >>
>>> >> --
>>> >> Jorge Arévalo
>>> >> Internet & Mobilty Division, DEIMOS
>>> >> jorge.arevalo at deimos-space.com
>>> >> http://mobility.grupodeimos.com/
>>> >> http://gis4free.wordpress.com
>>> >>
>>> >
>>> >
>>> > --
>>> > Andreas Neumann
>>> > http://www.carto.net/neumann/
>>> > http://www.svgopen.org/
>>> >
>>> >
>>>
>>
>>
>>
>> --
>> Mauricio de Paulo
>> Engenheiro Cartografo
>>
>>
>
>
> --
> Mauricio de Paulo
> Engenheiro Cartografo
>
>


-- 
Mauricio de Paulo
Engenheiro Cartografo
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