Changes between Version 124 and Version 125 of WKTRaster/SpecificationWorking03

Timestamp:

06/16/11 11:34:16 (2 years ago)

Author:

pracine

Comment:

--

WKTRaster/SpecificationWorking03

@@ -311 +311 @@
 '''ST_Resample(raster, method, originx, originy, pixelsizex, pixelsizey) -> raster'''
 
- '''Variant'''
-
-  1) ST_Resample(raster, method, raster) -> raster
-
- Recompute a raster in order to change its pixel size and/or the position of its upper left corner.
-
- The second parameter is the resampling method performed when computing new pixel values:
-  1) 'NEAREST NEIGHBOR'[[BR]]
-  2) 'LINEAR'[[BR]]
-  3) 'BICUBIC'
-
- The 3rd or 3rd-6th parameters define the pixel size of the resampling operation. For the 3rd parameter variant, the pixel size is taken from the pixel size of the raster parameter. For the 3rd-6th parameter variant, the pixel origin and dimensions are explicitly defined.
+ * Implemented as a wrapper around GDAL like done for ST_DumpAsPolygons()
+ * Resampling methods are the same as the one priovided by GDAL
+
+ '''Variants'''
+
+ * The '''first series of variants''' only change the pixelsize of the raster.
+
+ 1) ST_Resample(raster, pixelsize) - modify pixelsize only and resample using the default method
+
+ 2) ST_Resample(raster, method, pixelsize) - modify pixelsize and resample using the specified method
+
+ 3) ST_Resample(raster, pixelsizex, pixelsizey) - modify pixelsize with different values for x and y using the default method
+
+ 4) ST_Resample(raster, method, pixelsizex, pixelsizey) - modify pixelsize with different values for x and y using the specified method
+
+ * The '''second series of variants''' realign the raster and change the pixelsize
+
+ 5) ST_Resample(raster, x, y, pixelsize) - realign and modify pixelsize using the default method
+
+ 6) ST_Resample(raster, method, x, y, pixelsize) - realign and modify pixelsize using the specified method
+
+ 7) ST_Resample(raster, x, y, pixelsizex, pixelsizey) - realign and modify pixelsize with different values for x and y using the default method
+
+ 8) ST_Resample(raster, method, x, y, pixelsizex, pixelsizey) - realign and modify pixelsize with different values for x and y using the specified method
+
+ 9) ST_Resample(raster, x, y, pixelsizex, pixelsizey, skewx, skewy) - realign and modify pixelsize and skew with different values for x and y using the default method
+
+ 10) ST_Resample(raster, method, x, y, pixelsizex, pixelsizey, skewx, skewy) - realign and modify pixelsize and skew with different values for x and y using the specified method
+
+ * The '''third series of variants''' align and resample the raster to match the alignment, pixelsize and skew of an existing raster.
+ 
+ 11) ST_Resample(destraster, sourceraster)
+
+ '''Questions'''
+
+ * Should there be a band parameter?
+ * How does GDAL allow resampling?
+ * Which methods GDAL supports? ArcGIS supports NEAREST | BILINEAR | CUBIC | MAJORITY
+ * Does GDAL support change in skew?
 
 '''ST_SelectByValue(raster|geometry, 'expression') -> same type as first argument'''[[BR]]