|Version 171 (modified by pracine, 2 years ago)|
PostGIS Raster Home Page (formerly WKT Raster)
Welcome to the PostGIS Raster project home page!
PostGIS Raster is an ongoing project aiming at developing raster support in PostGIS. It is a new project very different from the previous PGRaster project and also very different from Oracle Spatial GeoRaster.
The goal of PostGIS Raster is to implement the RASTER type as much as possible like the GEOMETRY type is implemented in PostGIS and to offer a single set of overlay SQL functions (like ST_Intersects) operating seamlessly on vector and raster coverages.
- Linux - You will have to compile PostGIS Raster following the instructions in the Development Info section below.
- Windows Binaries - If you are running PostGIS on Windows, you can find fairly recent binaries of PostGIS Raster in the Windows Experimental Builds section along with binaries of the most recent PostGIS. These are for PostgreSQL 8.3, 8.4, upcoming 9.0. Note that development on the standalone wktraster project deployable on PostGIS 1.3-1.5 has stopped and all future versions and bug fixes of raster support will be packaged in the PostGIS 2.0 builds.
- Mac OSX Binaries - If you are running PostGIS on Mac OSX leopard or Snow Leopard, you can find fairly recent binaries of PostGIS and PostGIS Raster at KyngChaos PostgreSQL GIS packages include PostgreSQL 8.4, PostGIS 1.5, PostGIS Raster, and pgRouting.
- GDAL WKT Raster driver - A GDAL WKT Raster driver was developed following a Google Summer of Code 2009 grant obtained by Jorge Arevalo.
- Documentation - PostGIS Raster Documentation is under development.
- Function Reference - You will find every raster function documented as a chapter of the svn PostGIS documentation. Find also some more useful functions in this page?.
- Tutorials - This tutorial will show you how to load a huge raster coverage and intersect it with a vector coverage. Jorge has a whole series on PostGIS Raster and comparing activities you do in Oracle GeoRaster vs. how you would do them with PostGIS Raster. Check out Jorge's PostGIS Raster Tutorial Series.
- Book - PostGIS in Action has a full chapter dedicated to PostGIS Raster.
- Introducing PostGIS WKT Raster: Seamless Raster/Vector Operations in a Spatial Database - FOSS4G 2010, Barcelona, Spain, September 2010. PDF
- PostGIS WKT Raster. An Open Source alternative to Oracle GeoRaster - FOSS4G 2010, Barcelona, Spain, September 2010. PDF
- Introduction to WKT Raster - Geomatique 2009, Montréal, October 2009. PDF
- Original Project Presentation - rationale, examples and preliminary specifications: PPT, PDF (v1.0)
- With PostGIS 2.0: Spring 2011.
- Look at the planning page for a detailed schedule and to know how to contribute.
- Specifications - To know more about or contribute your ideas about the design of PostGIS Raster consult the working specification page. Accepted specifications are aggregates into the final specification page.
- Source Code, API and Bug report
- PostGIS Raster source code is available from the OSGeo Subversion repository
svn checkout https://svn.osgeo.org/postgis/spike/wktraster wktraster
- You can also download the latest development snapshot from: http://www.postgis.org/download/
- Compilation instructions are availables in the Documentation.
- API reference is available on PostGIS Raster Doxygen pages.
- See report with All tickets reported to PostGIS Raster
- PostGIS Raster source code is available from the OSGeo Subversion repository
Displaying PostGIS rasters
There are some options to display rasters stored in PostGIS.
- OpenJump - OpenJump will not display raster directly but a vectorization of the raster. Use a query like the following in the "Layer->Execute Query" dialog:
SELECT ST_AsBinary((ST_DumpAsPolygons(rast)).geom), (ST_DumpAsPolygons(rast)).val FROM rastertable
- QGIS - There is now a plugin for QGIS displaying PostGIS rasters. See the original thread, Mapeando o Brasil and the QGIS plugin page. For more info on the status of the plugin, contact Maurício de Paulo (mauricio.dev@…).
- gvSIG - There is also a plugin for gvSIG, the popular spanish open source GIS. See the presentation, the documentation and the project page. The plugin should be integrated into gvSIG 1.11. For more info on the status of the plugin, contact Nacho Brodin (ibrodin@…) at Prodevelop.
- MapServer - Some test were done to display PostGIS rasters with MapServer... and it works! See this post. More details in chapter 13 of PostGIS in Action.
For more details and examples of application using PostGIS Raster:
- PostGIS Raster has been designed following a thorough analysis of the numerous discussions about raster integration in PostGIS over the recent years. You can find most of the post to the PostGIS-users group related to raster integration in this page.
- Write to Pierre Racine
Overview of Planned PostGIS Raster Features
...is as simple as PostGIS...
- one table = one raster coverage (like a vector coverage)
- one row = one tile or one raster object (like a vector coverage where one row = one geometry)
- only one new type: RASTER (like the PostGIS GEOMETRY type)
- each raster tile has a pixel size, a width and a height, a variable number of band, a pixel type per band and a nodata value per band. Everything essential to do base raster GIS operations.
...is an extension of PostGIS to be installed separately
- merge with PostGIS might occur in the future...
...has an import/export mechanism similar to shp2pgsql
- raster2pgsql and pgsql2raster utilities allowing import/export of a single raster or a batch of raster into a tiled coverage.
...allows easy conversion from/to geometry/raster...
- ST_DumpToPolygons(raster) -> geometry set
- ST_AsRaster(geometry, pixelsize) -> raster
...implements base GIS raster operations available in most GIS...
- ST_Resample(raster, pixelsize, method) -> raster
- ST_Clip(raster|geometry,geometry) -> same type as first argument
- ST_Reclass(raster|geometry,string) -> same type as first argument
- ST_MapAlgebra(raster|geometry, raster), mathematical expression, "raster"|"geometry") -> raster/geometry
...introduces raster/geometry seamless geometry constructors...
- so you don't have to bother whether the layers are in raster or vector form when using analysis functions.
- ST_Intersection(raster|geometry, raster|geometry, "raster"|"geometry") -> raster/geometry
- ST_Union(raster|geometry, raster|geometry, "raster"|"geometry") -> raster/geometry
- ST_Accum(raster set|geometry set, "raster"|"geometry") -> raster/geometry
- ST_Transform(raster|geometry, SRID) -> same type as input
...and seamless geometry operators...
- ST_Intersects(raster|geometry, raster|geometry) -> boolean
- ST_Contains(raster|geometry A, raster|geometry B) -> boolean
...allows raster storage INSIDE the database (as WKB)...
- for efficient overlay analysis operations between vector and raster layers...
...or OUTSIDE the database (as JPEG or TIFF)...
- so desktop and web applications can quickly access and load raster tiles and nevertheless benefits from the powerful PostGIS GiST spatial index. Every PostGIS Raster SQL functions working with in-db raster tiles work seamlessly with out-db raster tiles.
...introduces the concept of raster objects...
- geographic features are stored as variable size raster tiles instead of polygons.
- allows vector to raster conversion without lost of information.
...is much more simple than PGRaster and Oracle GeoRaster! PostGIS Raster supports...
- only one type (instead of two in Oracle Spatial: SDO_GEORASTER & SDO_RASTER). In PostGIS Raster there are no differences between rasters and tiles: a tile is a raster and a raster is a tile. i.e. one row = one tile = one raster; one table = one raster coverage.
- no metadata (like PostGIS)
- no masks (you can create a mask as a band)
- no multiple dimensions (only two: x, y). Not to be confused with bands; PostGIS Raster DO supports multiband raster...
- no pyramids (reduced resolution coverages can be stored as a separate layer)
What do people think about PostGIS Raster?
Paul Ramsey (founder of PostGIS):
This proposal is better than any I have seen, addresses solving problems that if solved will provide actual new functionality and benefit to users, and clearly you've thought this through over some time
The functions PostGIS WKT Raster proposes look pretty cool actually and my vision of the benefits of storing raster in the database are covered in it
- WKTRasterIntro-Geomatique2009.pdf (1.1 MB) - added by pracine 3 years ago.
- FOSS4G2010_Pierre.pdf (0.9 MB) - added by pracine 3 years ago.
- FOSS4G2010_Jorge.pdf (4.2 MB) - added by pracine 3 years ago.
(4.8 MB) - added by jorgearevalo
2 years ago.
Video of PostGIS Raster gvSIG plugin.
- PierreRacine_FOSS4G-2011.pdf (2.3 MB) - added by pracine 20 months ago.