Changes between Version 58 and Version 59 of WKTRaster/SpecificationWorking01

Timestamp:

12/16/09 10:45:20 (15 years ago)

Author:

pracine

Comment:

—

WKTRaster/SpecificationWorking01

@@ -188 +188 @@
 [http://postgis.refractions.net/documentation/manual-1.4/ST_ConvexHull.html ST_ConvexHull(geometry)]
 
-
-'''Function definition for WKT Raster 0.1.6'''
+'''Function definitions for WKT Raster 0.1.6'''
+
+'''ST_Box2D(raster) -> BOX2D'''  Returns a BOX2D representing the maximum extents of the geometry.
+
+ This function replaces ST_Raster_to_box2d() and should be used for the "raster AS box2d" cast. It should also be used when creating indexes in gdal2wktraster.py.
 
 '''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_ConvexHull(raster) -> polygon geometry''' Returns the minimum convex geometry that encloses every pixel from the raster. 
+ This function should replace the actual ST_raster_envelope() function which is wrongly named.
+
+'''ST_ConvexHull(raster) -> polygon geometry''' Returns the minimum convex geometry that encloses every significant pixel from the 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).
@@ -201 +206 @@
 '''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_GetBBox(raster) (not yet implemented but planned) is replaced with ST_Envelope() since there is no equivalent function in PostGIS.
+
+ST_Raster_to_box2d(raster) should be renamed ST_box2d(raster).