Changes between Version 38 and Version 39 of WKTRaster/SpecificationWorking03

Timestamp:

03/14/11 11:36:31 (14 years ago)

Author:

pracine

Comment:

—

WKTRaster/SpecificationWorking03

@@ -213 +213 @@
  * a value: Replace any nodata value with this value and compute.
 
-Any remaining parameters to ST_MapAlgebraNgb could be passed to the summarizing functions for its own need.
+Any remaining parameters to ST_MapAlgebraNgb could be passed to the summarizing functions for its own need (e.g. "round" to specify that only the pixel forming a circle should be used in the computing).
 
 A number of predefined summarizing function could be delivered: ST_Average, ST_Majority, ST_Slope, ST_Aspect, 
@@ -221 +221 @@
 A more sophisticated version would pass a georeferenced raster instead of just a value matrix so that summarizing function could use this geoereference (e.g. to determine a value from the whole coverage (with ST_Value) when the neighbours are out of the bound of the raster). Passing a raster would allow existing raster functions (like the summarizing function which are to come) and remove the need to pass the dimension since they would correspond to the ST_Width & ST_Height functions. Only the optional "what to do with nodata values" could be needed and some additional parameters.
 
-There is three difficulties must be solved to impement this function:
+Three difficulties must be solved to implement this function:
 
  * The matrix values assigment must be optimized when passing from one pixel to the other.