= '''PostGIS WKT Raster Beta 0.2.4 Working Specifications''' = {{{ #!div style='background-color: #F4F4F4; padding: 5px; border: 1px solid gray; float: right; margin-left: 5px; width: 260px; font-size: small;' > '''Quick Links''' * [wiki:WKTRaster WKT Raster Home Page] * [wiki:WKTRaster/PlanningAndFunding Planning & Funding] * [wiki:WKTRaster/SpecificationWorking01 Beta 0.1.6 Working Specifications] * [wiki:WKTRaster/Documentation01 Beta 0.1.6 Documentation] * [wiki:WKTRaster/SpecificationWorking03 Working Specifications for Future Versions] }}} ---- == '''Objective B02x - Being able to intersect vector and raster to produce raster.''' == '''ST_Intersects(raster, raster)'''[[BR]] '''ST_AsRaster(geometry, pixelsize) -> raster'''[[BR]] '''ST_Intersection(geometry, val, raster, band) -> raster''' The first series of variant return a raster having the same extent as the provided raster. Variant 1: ST_Intersection(geometry, val, raster, band) -> raster Variant 2: ST_Intersection(raster, band, geometry, val) -> raster Variant 3: ST_Intersection(geometry, val, raster) -> raster Variant 4: ST_Intersection(raster, geometry, val) -> raster The second series of variant return a raster having the minimal extent. Variant 5: ST_Intersection(geometry, val, raster, band, 'TRIM') -> raster Variant 6: ST_Intersection(raster, band, geometry, val, 'TRIM') -> raster Variant 7: ST_Intersection(geometry, val, raster, 'TRIM') -> raster Variant 8: ST_Intersection(raster, geometry, val, 'TRIM') -> raster Return a two bands raster the first band containing only the pixels from the provided raster intersecting with the geometry and the second band containing the same area filled with the provided value. Non intersecting pixels are filled with nodata values. Variant 1 return a raster having the same extent as the provided raster. Variant 3, 4, 7 and 8 defaults the band number to 1. Variant 5 to 8 "trim" or "crop" the raster to the withvalue extent (removing extra nodata value pixels surrounding the extent of the resulting withvalue extent). Implementation details Rasterize the geometry as a new raster (ST_AsRaster(geometry, pixeltype, val, nodataval, raster)) and then copy only pixels for which both raster bands have a value. Should be implemented as a wrapper around ST_MapAlgebra after rasterizing the geometry to a raster having the same alignment as the raster. ---- == '''Objective B02x - Being able to use "group by" to accumulate tiles to form a new raster.''' == '''ST_Union(raster|geometry, raster|geometry, ‘raster’|’geometry’) -> raster/geometry'''[[BR]] '''ST_Accum(raster set|geometry set, ‘raster’|’geometry’) -> raster/geometry''' ---- == '''Objective B02x - Being able to set and get the skew of a raster in terms of rotation.''' == '''ST_SetRotation(raster, angle)''' Set the rotation of the raster. This method actually derive values for pixelsizex, pixelsizey, skewx and skewy based on the provided rotation angle. '''Open Question:''' PR: The angle should be provided in radian or in degree? '''ST_Rotation(raster) -> float64''' Return the georeference's rotation angle in (degree or radiant?) derived from the pixel size and the skew. PR: I think getting the rotation get no sence since the result of pixelsizes and skew is not necessarily a rotation. It make sence to set it though.