| 222 | | 3) If the second test returns TRUE, it checks if the geometry returned by ST_Polygon(raster, integer) intersects with the geometry. This test is slower since it involve the computation of the raster shape and it might involve the geometry shape. This test takes NODATA values into account. i.e. A geometry intersecting only with a NODATA value area of a raster is NOT actually not intersecting with this raster. This behavior may be controled by limiting the test to certain conditions as stated below. |
| 223 | | |
| 224 | | Variant 4 proceeds in a very similar way except that convex hulls of both rasters are computed and compared in step 2) and both shape of raster are computed and compared in step 3). |
| | 222 | 3) If the second test returns TRUE, it searches for a with value pixel touching the geometry. As soon as one pixel with value is found the function returns TRUE. A geometry intersecting only with a NODATA value area of a raster is NOT actually intersecting with this raster. This behavior may be controled by limiting the test to certain conditions as stated below. |
