Changes between Version 39 and Version 40 of PostGIS_Raster_SoC_Idea_2012/Distance_Analysis_Tools/document

Timestamp:

Aug 20, 2012, 10:39:04 AM (12 years ago)

Author:

qliu

Comment:

—

PostGIS_Raster_SoC_Idea_2012/Distance_Analysis_Tools/document

@@ -21 +21 @@
 == Creating an Euclidean Distance Raster in PostGIS Raster ==
 [[BR]][[BR]]
+
+=== ST_EuclideanDistance ===
+
+'''Name'''
+ST_EuclideanDistance - One raster, One band version:
+ Create a new one band raster generated from a point coverage and aligned with the provided reference raster or with raster specifications. The pixel values in the new raster represent the Euclidean distance from each pixel to the source points.
+
+'''Synopsis'''
+[[BR]]
+ST_EuclideanDistance(refrast raster,pixeltype text,sourceschema text,sourcetable text,sourcegeomcolumn text,double precision = -1);
+[[BR]]
+ST_EuclideanDistance(width integer,height integer,rastulx float8,rastuly float8,rastscalex float8,rastscaley float8,rastskewx float8,rastskewy float8,rastsrid integer,rastndv float8,pixeltype text,sourceschema text,sourcetable text,sourcegeomcolumn text,double precision = -1);
+[[BR]]
+
+'''Description'''
+[[BR]]
+ Create a new one band raster generated from a point coverage as source points. Pixel values in the output raster represent the Euclidean distance from each pixel to the source points. A reference raster will be provided, otherwise the raster specifications are provided. The new raster will have the same georeference, width and height as the reference raster or the raster specifications.
+ Source points are passed in by the database schema, table name and the geometry column name of the point coverage.
+ It is assumed that both the input reference raster and the output new raster has only 1 band.
+ If pixeltype is passed in, then the new raster will have a bond of that pixel type. If pixeltype is passed NULL, then the new raster band will have the same pixel type as the reference raster band. 
+ In the reference raster variant, it will use the same nodatavalue as the reference raster. In the raster specifications variant where no reference raster is provided, both nodatavalue and pixeltype have to be passed in with a NOT NULL value. 
+
+
 === Objectives ===