Changes between Version 109 and Version 110 of WKTRaster/SpecificationWorking01


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Timestamp:
Feb 3, 2010, 8:01:31 AM (14 years ago)
Author:
pracine
Comment:

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  • WKTRaster/SpecificationWorking01

    v109 v110  
    278278[[Image(WKTRasterAsPolygon.gif)]]
    279279
    280 '''ST_AsWKTPolygon(raster, band) -> wktgeomval set''' - Returns a set of "geomval" value, one for each group of pixel sharing the same value for the provided band.
     280'''ST_AsWKTPolygon(raster, integer) -> wktgeomval set''' - Returns a set of "geomval" value, one for each group of pixel sharing the same value for the provided band.
    281281
    282282 This is a set-returning function (SRF). A "wktgeomval " value is a complex type composed of a the wkt representation of a geometry (one for each group of pixel sharing the same value) and the value associated with this geometry. These values are always returned as a value of type double precision. The shape of each polygon follow pixels edges.
     
    295295'''ST_Intersects(raster, integer, geometry) -> boolean''' - Returns TRUE if the geometry and the raster "spatially intersect" - (share any portion of space) and FALSE if they don't (they are Disjoint).
    296296
    297  Variant 1: ST_Intersects(geometry, raster, integer) -> boolean
     297 Variant 1: ST_Intersects(geometry, raster, integer) -> boolean -- the third parameter is the raster band number
    298298
    299299 Variant 2: ST_Intersects(geometry, raster) -> boolean -- default to band # 1
     
    327327 It might be faster to skip test 2) if this test is not signicantly faster than test 3).
    328328
    329 '''ST_Intersection(raster, integer, geometry) -> geometry''' - Returns a set of "geomval" value representing the shared portion of the geometry and the raster areas sharing a common meaningfull values.
     329'''ST_Intersection(raster, integer, geometry) -> geometry''' - Returns a set of "geomval" value representing the shared portion of the geometry and the raster band areas sharing a common meaningfull values. The integer parameter is the band number of the raster.
    330330
    331331 Variant 1:
    332332
    333333  ST_Intersection(raster, geometry) -> geometry -- default to band # 1[[BR]]
    334   ST_Intersection(geometry, raster, integer) -> geometry[[BR]]
     334  ST_Intersection(geometry, raster, integer) -> geometry -- the integer parameter is the band number of the raster[[BR]]
    335335  ST_Intersection(geometry, raster) -> geometry -- default to band # 1
    336336
    337337 Variant 2:
    338338
    339   ST_Intersection(raster, integer, geometry, 'raster') -> raster[[BR]]
     339  ST_Intersection(raster, integer, geometry, 'raster') -> raster -- the integer parameter is the band number of the raster[[BR]]
    340340  ST_Intersection(raster, geometry, 'raster') -> raster -- default to band # 1
    341341
    342342 Variant 3:
    343343
    344   ST_Intersection(geometry, raster, integer, 'raster') -> raster[[BR]]
     344  ST_Intersection(geometry, raster, integer, 'raster') -> raster -- the integer parameter is the band number of the raster[[BR]]
    345345  ST_Intersection(geometry, raster, 'raster') -> raster -- default to band # 1
    346346
    347347 Variant 4:
    348348
    349   ST_Intersection(raster, integer, raster, integer) -> raster[[BR]]
    350   ST_Intersection(raster, raster) -> raster -- default to band # 1
     349  ST_Intersection(raster, integer, raster, integer) -> raster -- the integer parameters are the band number of the rasters[[BR]]
     350  ST_Intersection(raster, raster, integer) -> raster -- default first raster to band # 1
     351  ST_Intersection(raster, integer, raster) -> raster -- default second raster to band # 1
     352  ST_Intersection(raster, raster) -> raster -- default both rasters to band # 1
    351353
    352354 Variant 5:
    353355
    354356  ST_Intersection(raster, integer, raster, integer, 'geometry') -> geometry[[BR]]
    355   ST_Intersection(raster, raster, 'geometry') -> geometry -- default to band # 1
     357  ST_Intersection(raster, raster, integer, 'geometry') -> geometry -- default first raster to band # 1
     358  ST_Intersection(raster, integer, raster, 'geometry') -> geometry -- default second raster to band # 1
     359  ST_Intersection(raster, raster, 'geometry') -> geometry -- default both raster to band # 1
    356360
    357361 This is a set-returning function (SRF). It returns a set of "geomval" representing the point set intersection of the geometry and the areas of the raster sharing a common meaningfull value (NODATA values ARE taken into account). The raster is first polygonised using ST_AsPolygon(raster) and ST_Intersection(geometry, geometry) is then performed between the provided geometry and all the geometries resulting from the polygonisation of the raster.
     
    384388== '''Objective 0.1.6f - Being able to return a JPEG, a TIFF or a PNG.''' ==
    385389 
    386 '''ST_bytea(raster, band) -> raster'''[[BR]]
     390'''ST_bytea(raster, integer) -> raster''' -- the integer parameters is the band number of the raster.[[BR]]
    387391What is does?
    388392
     
    406410----
    407411
    408 '''ST_Band(raster, band) -> raster'''[[BR]]
     412'''ST_Band(raster, integer) -> raster''' -- the integer parameters are the band number of the rasters.[[BR]]
    409413Return a single band from a multiband raster. If "band" is greater than the value returned by ST_GetNumBands(), the function returns the last band. This function should be used to select a band before converting it to JPEG, TIFF, PNG, SVG or KML with the corresponding function. e.g. '''ST_AsTIFF(ST_Band(raster, band))
    410414