PostGIS Raster : Extending PostgreSQL for The Support of ... - CoDE

Chapter 5
User Guide
Sometimes storing data using raster is the only choice such as imagery is only available in raster
format. Moreover, users can get many other advantages resulting from the nature of raster data,
which is a matrix of cell values. For example, this simple data structure offers the ability to represent
continuous surfaces as a grid of cell values and so enables easy spatial and statistical surface analysis.
The ability to uniform storage as points, lines and polygons, which are all vector features, could also
be stored using raster data.
The following section introduces instructions about how to execute some basic operations such as
importing, exporting raster data, conversion and intersection between raster and vector data, along
with other abilities that PostGIS Raster could offer to users.
5.1 Store and Manage Rasters
5.1.1 Import Rasters
User can import rasters from existing raster images stored in file system using raster2pgsql
Python loader:
(1) raster2pgsql.py -r "c:/temp/mytiffolder/*.tif" -t mytable -s 4326 -o table_name.sql
(2) psql -d postgisdb -f table_name.sql -U -W
The first command (1) generates a sql file that loads file_name.tif with SRID 4326 into a
new table called mytable. The second command (2) runs the SQL script for loading the data into
postgisdb.
Or users can create their own rasters from SQL command:
CREATE TABLE dummy_rast(rid integer, rast raster);
INSERT INTO dummy_rast(rid, rast)
VALUES
-- Raster: 5 x 5 pixels, 3 bands, PT_8BUI pixel type, NODATA = 0
(1,(’01000003009A9999999999A93F9A9999999999A9BF000000E02B274A4
1000000007719564100000000000000000000000000000000FFFFF
FFF050005000400FDFEFDFEFEFDFEFEFDF9FAFEFEFCF9FBFDFEFEF
DFCFAFEFEFE04004E627AADD16076B4F9FE6370A9F5FE59637AB0E
54F58617087040046566487A1506CA2E3FA5A6CAFFBFE4D566DA4C
B3E454C5665’)::raster);
5.1.2 Get and Set The Raster Properties
• Upper left corner coordinates and transformation parameters
–Get the upper left corner coordinates of all rasters in the table:
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