Changes between Version 26 and Version 27 of WKTRaster/SpecificationWorking02


Ignore:
Timestamp:
09/03/10 14:26:58 (14 years ago)
Author:
pracine
Comment:

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  • WKTRaster/SpecificationWorking02

    v26 v27  
    7575 '''Variants'''
    7676
    77   1) ST_Clip(raster, ulx, uly, lrx, lry) -> raster
     77  1) ST_Clip(raster, ulx float8, uly float8, width int, height int) -> raster
    7878
    7979  2) ST_Clip(raster, geometry) -> raster
     
    8383
    8484
    85  Variant 1) takes the upper left and lower left corner of the desired zone. Variant 2) determine the extent of this zone from the extent of a geometry. Variant 3) determine the extent of this zone from the extent of a geometry and set all pixel outside the geometry to no data values.
     85 Variant 1 takes the upper left corner, the width and the height of the desired zone. Variant 2 determine the extent of this zone from the extent of a geometry. Variant 3 determine the extent of this zone from the extent of a geometry and set all pixel outside the geometry to no data values.
    8686
    8787 If the geometry is totally included into one pixel (a point for example), only this pixel is kept in the returned raster.
     
    9292 
    9393 newrast := ST_AddBand(ST_MakeEmptyRaster(x2 - x1, y2 - y1, ST_Raster2WorldCoordX(rast, x1, y2), ST_Raster2WorldCoordY(rast, x1, y2), ST_PixelSizeX(rast), ST_PixelSizeY(rast),ST_SkewX(rast),ST_SkewY(rast), ST_SRID(rast)), ‘1BB’, 1, 0)
    94  newrast := ST_MultiBandMapAlgebra(rast, newrast, ‘r1’, ‘INTERSECTION’)
     94 newrast := ST_MultiBandMapAlgebra(rast, newrast, ‘rast1’, ‘INTERSECTION’)
    9595
    9696 Could also be implemented as ST_Intersection -> ST_Band(ST_Intersection(geometry, raster, band, “TRIM”), 1) Would require some kind of TRIM and would be slower.