[postgis-users] [Qgis-developer] Fwd: WKTRaster Plugin 0.1

[Maurício de Paulo]

Great. I've included a new combobox on the ui. I'm going to implement it and
release as version 0.3.
Any other sugestions on what a "Load postgis raster" plugin should do?
Best regards,
Mauricio de Paulo

2010/11/30 Jorge Arévalo <jorge.arevalo at deimos-space.com>

> 2010/11/30 Maurício de Paulo <mauricio.dev at gmail.com>:
> > Yes, the main issue we found was the performance of display. So something
> > inside the driver is slowing the reading process done by qgis.
> > I took a look at the MODE option. It can be set in the user interface on
> my
> > plugin. I think that a combobox storing "Read whole table" "Read one row"
> > and "Read entire database" should pass the right options. Is it the real
> > interpretation of this parameter? Any sugestions?
> > Best regards,
> > Mauricio de Paulo
> >
>
> Yes, Basically, one spatial query is executed for each data petition.
> That can (must) be improved. I know it.
>
> About the parameter, yes. There is, basically, 3 ways of using the driver:
>
> - Providing only a database name, and optionally, a schema name: The
> driver returns all the existent raster tables as subdatasets
> - Providing a database name, a table name and optionally, a column
> name: The driver returns all the rows of the raster table as a
> subdataset. This is, consider each row as a different raster. The same
> if you provide "mode=1" as parameter.
> - Providing a database name, a table name and "mode = 2": The driver
> consider that all the rows of the table are tiles of a bigger raster
> coverage, and constructs one raster object based in the whole extent
> of all the raster tiles. For now, just working with regularly blocked
> rasters.
>
> So, about your combobox, the option "read the entire database" (or
> "read one schema") should disable the selection of a table name (it is
> the first of the 3 points).
>
> Best regards,
>
> --
> Jorge Arévalo
> Internet & Mobilty Division, DEIMOS
> jorge.arevalo at deimos-space.com
> http://mobility.grupodeimos.com/
> http://gis4free.wordpress.com
>
>
> P.S.: My mails to QGIS list are rejected, but I think that could be
> interesting. I'll subscribe to the list.
>
> >
> > 2010/11/30 Jorge Arévalo <jorge.arevalo at deimos-space.com>
> >>
> >> 2010/11/30 Maurício de Paulo <mauricio.dev at gmail.com>:
> >> > I've been using GDAL 1.7 and postgis 1.5.1
> >> > Both postgis' windows and ubuntu versions are able to load the rasters
> >> > fine.
> >> > We've encountered some trouble with what we believe is the "regular
> >> > blocking" issue.
> >> > wktraster's QGIS plugin and MapServer source were tested on ubuntu
> 10.04
> >> > with ubuntugis binaries.
> >> > Perfomance looks like a huge issue at the moment. I didn't investigate
> >> > why.
> >> > I can probably take look back at this issue when I get back home to my
> >> > ubuntu box. I can't test on windows because there is no QGIS compiled
> >> > with
> >> > gdal 1.7 for windows prebuilt.
> >> > This new gdal driver version was included in which gdal release? Maybe
> >> > we
> >> > can recompile everything and test again.
> >> > Best regards,
> >> > Mauricio
> >> >
> >>
> >> Yes, the old version of the driver had some known (by me) problems:
> >>
> >> - Depends on the information stored in "raster_columns" table, in
> >> PostGIS installation, and it shouldn't.
> >> - Performance. I need to review this. It's a question of PostGIS
> queries.
> >>
> >> In October, I commited a new version with some improvements. It's in
> >> GDAL trunk since release 20912
> >> (http://trac.osgeo.org/gdal/changeset/20912). Anyway, I'd like to
> >> improve more things in this driver. The reading process is the big
> >> issue right now. The best way to read blocks of data.
> >>
> >> If you use it, the most important thing is now you need to specify an
> >> extra parameter: "mode". Further information here:
> >> http://trac.osgeo.org/gdal/wiki/frmts_wtkraster.html
> >>
> >> Best regards,
> >> --
> >> Jorge Arévalo
> >> Internet & Mobilty Division, DEIMOS
> >> jorge.arevalo at deimos-space.com
> >> http://mobility.grupodeimos.com/
> >> http://gis4free.wordpress.com
> >>
> >> > 2010/11/29 Jorge Arévalo <jorge.arevalo at deimos-space.com>
> >> >>
> >> >> Good news! Which version of GDAL/PostGIS are you using? I commited a
> >> >> new version of the GDAL driver on October, and included WKT Raster as
> >> >> official part of PostGIS on September 26th.
> >> >>
> >> >> On Mon, Nov 29, 2010 at 9:40 PM, Maurício de Paulo
> >> >> <mauricio.dev at gmail.com> wrote:
> >> >> > Ok, after a few minutes of implementation here it is. Now the
> plugin
> >> >> > lists
> >> >> > the tables from the database and shows some of it's metadata. Now I
> >> >> > think
> >> >> > it's fully functional. If anyone finds a bug , please tell me.
> >> >> > Best regards,
> >> >> >
> >> >> > On Mon, Nov 29, 2010 at 3:50 PM, Maurício de Paulo
> >> >> > <mauricio.dev at gmail.com>
> >> >> > wrote:
> >> >> >>
> >> >> >> Hi Jorge,
> >> >> >> Good news. The plugin wktraster is exactly a tool to connect qgis
> to
> >> >> >> postgis rasters through GDAL and visualize the data.
> >> >> >> Stefan asked about the processing. This is something the plugin
> >> >> >> doesn't
> >> >> >> do.
> >> >> >> I've tested with a friend both qgis (with the plugin) and
> mapserver
> >> >> >> loading postgis rasters. Both worked fine, and the only
> requirement
> >> >> >> is
> >> >> >> qgis
> >> >> >> compiled against gdal 1.7.
> >> >> >> I'm interested in updating the plugin this week to work as I've
> >> >> >> planned.
> >> >> >> It's going to speak for itself.
> >> >> >> Best Regards,
> >> >> >> Mauricio
> >> >> >> Ps.: Anyone willing to help and join this effort is always
> welcome.
> >> >> >>
> >> >> >> On Mon, Nov 29, 2010 at 3:45 PM, Jorge Arévalo
> >> >> >> <jorge.arevalo at deimos-space.com> wrote:
> >> >> >>>
> >> >> >>> Hi,
> >> >> >>>
> >> >> >>> If you want a GDAL version compiled with PostGIS Raster support
> on
> >> >> >>> Windows, you may take a look here:
> >> >> >>> http://vbkto.dyndns.org:1280/sdk/
> >> >> >>>
> >> >> >>> Visualizing PostGIS Raster data via GDAL driver is one of my TODO
> >> >> >>> tasks. I don't have too much free time now, but if you're
> >> >> >>> interested
> >> >> >>> on this topic, and you're going to test it, please let me know.
> >> >> >>> There
> >> >> >>> are more people interested on that, and I'm providing support to
> >> >> >>> some
> >> >> >>> of them (not as much support as I'd like, because the time...)
> >> >> >>>
> >> >> >>> Best regards,
> >> >> >>>
> >> >> >>> --
> >> >> >>> Jorge Arévalo
> >> >> >>> Internet & Mobilty Division, DEIMOS
> >> >> >>> jorge.arevalo at deimos-space.com
> >> >> >>> http://mobility.grupodeimos.com/
> >> >> >>> http://gis4free.wordpress.com
> >> >> >>>
> >> >> >>> 2010/11/29 Stefan Keller <sfkeller at gmail.com>:
> >> >> >>> > Ok (I'm cross posting to qgis-developer and postgis-users).
> >> >> >>> >
> >> >> >>> > I'm still not sure if I did express myself clearly:
> >> >> >>> > You say, that under Windows, there's no QGIS compiled against
> >> >> >>> > GDAL
> >> >> >>> > 1.7/1.8 with PostGIS Raster support?
> >> >> >>> >
> >> >> >>> > What I finally dream of, is using QGIS to display the results
> of
> >> >> >>> > a
> >> >> >>> > SQL
> >> >> >>> > query (either as raster or vector) against at least one raster
> >> >> >>> > layer.
> >> >> >>> > This query contains raster constructors (like ST_Intersection)
> >> >> >>> > and
> >> >> >>> > operations (like ST_Reclass; see
> >> >> >>> > http://trac.osgeo.org/postgis/wiki/WKTRaster).
> >> >> >>> >
> >> >> >>> > Any suggestions?
> >> >> >>> > -S.
> >> >> >>> >
> >> >> >>> >
> >> >> >>> > 2010/11/29 Maurício de Paulo <... at gmail.com>:
> >> >> >>> >> Hi Stefan,
> >> >> >>> >>
> >> >> >>> >> WKTRaster Plugin just repasses the right information to the
> GDAL
> >> >> >>> >> driver.
> >> >> >>> >> It's not a new qgis driver.
> >> >> >>> >> I'm planning on implementing the table listing using pyqt this
> >> >> >>> >> week. I
> >> >> >>> >> was a
> >> >> >>> >> little delayed by my master's application.
> >> >> >>> >>
> >> >> >>> >> The idea in the plugin is simply find the QGIS's conections
> >> >> >>> >> available,
> >> >> >>> >> list
> >> >> >>> >> the raster tables inside postgis and pass the right arguments
> to
> >> >> >>> >> the
> >> >> >>> >> gdal
> >> >> >>> >> driver.
> >> >> >>> >>
> >> >> >>> >> At the moment I haven't found any gdal 1.7 windows build with
> >> >> >>> >> QGIS.
> >> >> >>> >> GDAL 1.7
> >> >> >>> >> introduces wktraster. The driver conects to postgis raster and
> >> >> >>> >> read
> >> >> >>> >> it
> >> >> >>> >> as a
> >> >> >>> >> binary. It's still VERY unstable and gdal version 1.8 seems to
> >> >> >>> >> be
> >> >> >>> >> greatly
> >> >> >>> >> improved.
> >> >> >>> >> So what a windows user need to get the plugin to work is a
> >> >> >>> >> (still
> >> >> >>> >> not
> >> >> >>> >> found)
> >> >> >>> >> qgis compiled against gdal 1.7.
> >> >> >>> >> You can compile your's from source if needed.
> >> >> >>> >>
> >> >> >>> >> So, as far as qgis to wktraster, with the plugin qgis reads
> the
> >> >> >>> >> wktraster as
> >> >> >>> >> a regular raster. Just for show. If you did some kind of
> >> >> >>> >> processing
> >> >> >>> >> and
> >> >> >>> >> populated a new raster table, qgis is going to read that
> result
> >> >> >>> >> too.
> >> >> >>> >> The
> >> >> >>> >> plugin is not intended (at the moment at least) to raster
> >> >> >>> >> processing
> >> >> >>> >> inside
> >> >> >>> >> postgis. It just loads the table to the screen.
> >> >> >>> >>
> >> >> >>> >> In the future, with a more stable wktraster probably someone
> (or
> >> >> >>> >> me)
> >> >> >>> >> is
> >> >> >>> >> going to write a set of wktraster's tools as a plugin, but for
> >> >> >>> >> the
> >> >> >>> >> moment it
> >> >> >>> >> should be run as sql. I advise postgis manager's to the task.
> >> >> >>> >>
> >> >> >>> >> Best regards,
> >> >> >>> >>
> >> >> >>> >>
> >> >> >>> >> 2010/11/29 Stefan Keller <... at gmail.com>
> >> >> >>> >>>
> >> >> >>> >>> Hi,
> >> >> >>> >>>
> >> >> >>> >>> There are new versions around of "PostGIS Raster"
> >> >> >>> >>> (renamed from formerly known "PostGIS WKT Raster").
> >> >> >>> >>>
> >> >> >>> >>> What's the status of your "WKTRaster Plugin 0.1"?
> >> >> >>> >>> I assume it's rendering the raster values (e.g. from
> >> >> >>> >>> ST_AsBinary)
> >> >> >>> >>> -
> >> >> >>> >>> not the polygons/geomvals (from ST_DumpAsPolygons), right?
> >> >> >>> >>> Is there a chance to get it running on Windows too?
> >> >> >>> >>> Are there other plugins?
> >> >> >>> >>>
> >> >> >>> >>> Yours, S.
> >> >> >>> > _______________________________________________
> >> >> >>> > postgis-users mailing list
> >> >> >>> > postgis-users at postgis.refractions.net
> >> >> >>> > http://postgis.refractions.net/mailman/listinfo/postgis-users
> >> >> >>> >
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> --
> >> >> >> Mauricio de Paulo
> >> >> >> Engenheiro Cartografo
> >> >> >>
> >> >> >
> >> >> >
> >> >> >
> >> >> > --
> >> >> > 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
> >> >
> >> >
> >> >
> >> > --
> >> > Mauricio de Paulo
> >> > Engenheiro Cartografo
> >> >
> >> >
> >
> >
> >
> > --
> > Mauricio de Paulo
> > Engenheiro Cartografo
> >
> >
>



-- 
Mauricio de Paulo
Engenheiro Cartografo
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