ST_PixelAsPoint — 返回像素左上角的点几何形状。
geometry ST_PixelAsPoint(raster rast, integer columnx, integer rowy);
geometry ST_PixelAsPoint(
)
返回像素左上角的点几何形状。
可用性：2.1.0
SELECT ST_PixelAsPoint(rast, 1, 1) FROM dummy_rast WHERE rid = 1;
POINT(0.5 0.5)
ST_DumpAsPolygons, ST_PixelAsPolygon, ST_PixelAsPolygons, ST_PixelAsPoints, ST_PixelAsCentroid, ST_PixelAsCentroids