Changes between Version 57 and Version 58 of WKTRaster/SpecificationWorking01

Timestamp:

Dec 16, 2009, 10:27:37 AM (14 years ago)

Author:

pracine

Comment:

—

WKTRaster/SpecificationWorking01

@@ -191 +191 @@
 '''Function definition for WKT Raster 0.1.6'''
 
-'''ST_GetBBox(raster) -> polygon geometry''' - Replaced with ST_Envelope() since there is no equivalent function in PostGIS.
-
 '''ST_Envelope(raster) -> polygon geometry''' Returns the minimum bounding box for the supplied raster, as a geometry. If the raser is rotated, the envelope is a non-rotated box enclosing the rotated raster.
 
-'''ST_Shape(raster) -> polygon geometry'''- Replaced with ST_ConvexHull(raster).
-
 '''ST_ConvexHull(raster) -> polygon geometry''' Returns the minimum convex geometry that encloses every pixel from the raster. 
 
- By default the resulting polygon take the NODATA values into account and enclose only pixels having a value different than the NODATA value. The ST_ConvexHull(raster, 'WITHNODATA') variant do not take the NODATA value into account and generally return a square or rectangle polygon that can be rotated or not. If the raster is not rotated ST_ConvexHull(geometry, 'WITHNODATA') is equivalent to ST_Envelope(raster).
+ By default the resulting polygon TAKES the NODATA values into account. The resulting polygon enclose only pixels actually having a value (different than the NODATA value). The ST_ConvexHull(raster, 'WITHNODATA') variant DO NOT TAKE the NODATA value into account. It generally returns a square or rectangle polygon that can be rotated or not depending on the rotation of the raster. If the raster is not rotated ST_ConvexHull(geometry, 'WITHNODATA') is (almost) equivalent to ST_Envelope(raster).
+
+'''ST_Shape(raster) -> polygon geometry'''- Returns .
 
 '''ST_AsPolygon(raster) -> polygon geometry set''' Returns a 
+
+ST_GetBBox(raster) is replaced with ST_Envelope() since there is no equivalent function in PostGIS.
+
 
 '''ST_Intersects(raster|geometry, raster|geometry)'''[[BR]][[BR]]