Use ST_RPCRectify to rectify raster data - ApsaraDB RDS

Rectifies a raster object using rational polynomial coefficients (RPC) and returns the rectified raster.

Syntax

raster ST_RPCRectify(raster rast,
                     raster dem DEFAULT NULL,
                     cstring rectifyOption DEFAULT '{}',
                     cstring storageOption DEFAULT '{}',
                     cstring parallelOption DEFAULT '{}')

Parameters

Parameter	Type	Default	Description
`rast`	raster	—	The raster object to rectify. Must contain RPC information.
`dem`	raster	NULL	A digital elevation model (DEM) to reference during rectification.
`rectifyOption`	cstring (JSON)	`'{}'`	Rectification options.
`storageOption`	cstring (JSON)	`'{}'`	Storage options for the output raster.
`parallelOption`	cstring (JSON)	`'{}'`	Parallel processing options.

Note The input raster object must contain RPC information.

rectifyOption parameters

Parameter	Type	Default	Description
`resample`	string	`Near`	The resampling method. Valid values: `Near`, `Average`, `Cubic`, `Bilinear`.
`outSrid`	integer	Same as source	The spatial reference ID (SRID) of the output raster.
`nodataValue`	float8 or float8[]	NULL	The nodata value for the output raster. Specify a single value to apply it to all bands, or an array (for example, `[0, 0, 0]`) with one element per band. If not set, the value defaults to the source raster's nodata value, or `0` if the source has none.
`RPC_DEM_MISSING_VALUE`	float8	`0`	The height value to use when the `dem` parameter has a nodata value or the pixel falls outside the valid DEM extent.

storageOption parameters

Parameter	Type	Default	Description
`chunking`	boolean	Same as source	Specifies whether to store the output raster as chunks.
`chunkdim`	string	Same as source	The chunk dimensions. Takes effect only when `chunking` is `true`.
`chunktable`	string	`''`	The name of the chunk table. Set to `''` to create a temporary chunk table with a random name in the current session. Temporary tables are deleted when the session ends. Specify a name to persist the output raster beyond the session. If the parallel method does not support anonymous chunk tables, create the chunk table in advance.
`compression`	string	Same as source	The compression format. Valid values: `NONE`, `JPEG`, `ZLIB`, `PNG`, `LZO`, `LZ4`, `JP2K`.
`quality`	integer	Same as source	The compression quality. Applies only to JPEG compression.
`interleaving`	string	Same as source	The band interleaving method. Valid values: `bip` (band interleaved by pixel, BIP), `bil` (band interleaved by line, BIL), `bsq` (band sequential, BSQ).
`endian`	string	Same as source	The byte order of the output raster. Valid values: `NDR` (little endian), `XDR` (big endian).

Examples

CREATE TABLE IF NOT EXISTS raster_table(id integer, rast raster);

-- Load the RPC raster.
INSERT INTO raster_table VALUES(1, ST_ImportFrom('t_chunk', '<RAST_DATA_DIR>/rpc.tif', '{}'));

-- Load the DEM raster.
INSERT INTO raster_table VALUES(2, ST_ImportFrom('t_chunk', '<RAST_DATA_DIR>/rpc_dem.tif', '{}'));

CREATE TABLE raster_result(id integer, rast raster);

-- Rectify without a DEM, using nearest neighbor (NNS) resampling.
INSERT INTO raster_result(id, rast)
SELECT 10, ST_RPCRectify(
    rast,
    NULL,
    '{"resample": "Near"}',
    '{"chunking": true, "chunkdim": "(256,256,1)", "interleaving": "bsq", "chunktable": "t_chunk"}'
)
FROM raster_table
WHERE id = 1;

-- Rectify with a DEM and output in EPSG:32635, using 8 parallel workers.
INSERT INTO raster_result(id, rast)
SELECT 11, ST_RPCRectify(
    rast,
    (SELECT rast FROM raster_table WHERE id = 2),
    '{"resample": "Near", "outSrid": 32635}',
    '{"chunking": true, "chunkdim": "(256,256,1)", "interleaving": "bsq", "chunktable": "t_chunk"}',
    '{"parallel": 8}'
)
FROM raster_table
WHERE id = 1;