SDO_GEOR.warp

Format

SDO_GEOR.warp(
     inGeoRaster      IN SDO_GEORASTER, 
     pyramidLevel     IN NUMBER DEFAULT 0, 
     outSRS           IN NUMBER, 
     cropArea         IN SDO_GEOMETRY DEFAULT NULL, 
     dimensionSize    IN SDO_NUMBER_ARRAY DEFAULT NULL, 
     layerNumbers     IN VARCHAR2 DEFAULT NULL, 
     elevationParam   IN VARCHAR2 DEFAULT NULL, 
     resampleParam    IN VARCHAR2 DEFAULT NULL, 
     storageParam     IN VARCHAR2 DEFAULT NULL, 
     outGeoRaster     IN OUT SDO_GEORASTER, 
     bgValues         IN SDO_NUMBER_ARRAY DEFAULT NULL,
     parallelParam    IN VARCHAR2 DEFAULT NULL);

or

SDO_GEOR.warp(
     inGeoRaster      IN SDO_GEORASTER, 
     pyramidLevel     IN NUMBER DEFAULT 0, 
     outSRS           IN NUMBER, 
     cropArea         IN SDO_GEOMETRY DEFAULT NULL, 
     dimensionSize    IN SDO_NUMBER_ARRAY DEFAULT NULL, 
     layerNumbers     IN VARCHAR2 DEFAULT NULL, 
     elevationParam   IN VARCHAR2 DEFAULT NULL, 
     resampleParam    IN VARCHAR2 DEFAULT NULL, 
     storageParam     IN VARCHAR2 DEFAULT NULL, 
     rasterBlob       IN OUT NOCOPY BLOB, 
     outArea          OUT SDO_GEOMETRY, 
     outWindow        OUT SDO_NUMBER_ARRAY, 
     bgValues         IN SDO_NUMBER_ARRAY DEFAULT NULL,
     parallelParam    IN VARCHAR2 DEFAULT NULL);

Description

Perform geometric transformation on the input GeoRaster object to produce an output GeoRaster object with the specified output spatial reference system.

Parameters

inGeoRaster

GeoRaster object on which to perform the operation. It must be georeferenced (see Georeferencing GeoRaster Objects and Advanced Georeferencing).

pyramidLevel

Pyramid level of the source GeoRaster object for the operation.

For BLOB output, this parameter is required.
For SDO_GEORASTER output, if this parameter is null, all pyramid levels from the input GeoRaster object are processed.
If the number 0 or greater is specified, only that pyramid level is used for the rectification, producing a result in scale based on that pyramid level image.

outSRS

Coordinate system (spatial reference system) for the output GeoRaster object. Must be either null or a value from the SRID column of the MDSYS.CS_SRS table. If it is null, the output GeoRaster object will have the same SRID as the input GeoRaster object.

cropArea

Defines the shape of the area to be covered by the output image. Areas outside this polygon will be filled with the background value. If this parameter is not specified, no cropping is performed.

dimensionSize

Dimension size array of the GeoRaster object. Defines the extent of the image in cell space.

layerNumbers

String specifying one or more numbers of layers from inGeoRaster to be transferred to outGeoRaster. Use commas to delimit numbers or ranges, and use a hyphen to indicate a range. Example: ’1,3-5,7’ for layers 1, 3, 4, 5, and 7. If this parameter is null (the default), all the layers will be processed.

elevationParam

A string containing one or more of the elevation parameters average (average surface height), scale (scale value applied to all DEM values), and offset (offset applied to all DEM values), where the new value is (value + offset) * scale. This parameter must be a quoted string that contains one or more keyword=value pairs (for example, 'average=800 scale=3.2808399 offset=10'). If this parameter is null, 0 is assumed for average and offset, and 1 is used for scale. Any scale and offset values are ignored if DEM is not specified.

The use of the elevationParam parameter requires that the input GeoRaster object have a 3D model SRID.

When the input GeoRaster object has a 3D model SRID, the average elevation is important for defining the extents of the output image. If that information is available, it should be specified even if DEM is also specified. If the average elevation is not specified, the procedure will calculate an approximate value for the average elevation.

Note:

For any numbers in string (VARCHAR2) parameters to GeoRaster subprograms, the period (.) must be used for any decimal points regardless of the locale.

resampleParam

A comma-separated quoted string of keyword=value pairs for specifying resampling parameters. See the Usage Notes for more information.

storaageParam

A string specifying storage parameters, as explained in Storage Parameters.

outGeoRaster

GeoRaster object to hold the result of the operation. Must be either a valid existing GeoRaster object or an empty GeoRaster object. (Empty GeoRaster objects are explained in Blank and Empty GeoRaster Objects.) Cannot be the same GeoRaster object as inGeoRaster

rasterBlob

BLOB to hold the output reflecting the rectification. It must exist or have been initialized before the operation.

outArea

An SDO_GEOMETRY object containing the MBR (minimum bounding rectangle) in the model coordinate system of the resulting object.

outWindow

An SDO_NUMBER_ARRAY object identifying the coordinates of the upper-left and lower-right corners of the output window in the cell space.

bgValues

Background values for filling partially empty raster blocks. It is only useful when the source GeoRaster object has empty raster blocks and the current operation leads to partially empty raster blocks (see Empty Raster Blocks). The number of elements in the SDO_NUMBER_ARRAY object must be either one (same filling value used for all bands) or the band dimension size (a different filling value for each band, respectively). For example, SDO_NUMBER_ARRAY(1,5,10) fills the first band with 1, the second band with 5, and the third band with 10. The default bgValues are zero (0).

The filling values must be valid cell values as specified by the target cell depth background values for filling sparse data.

parallelParam

Specifies the degree of parallelism for the operation. If specified, must be in the form parallel=n, where n is greater than 1. The database optimizer uses the degree of parallelism specified by this parameter. If not specified, then by default there is no parallel processing. (For more information, see Parallel Processing in GeoRaster.)

If parallelism is specified, the procedure performs an internal commit operation. If an error occurs (even if it is raised by the Oracle parallel server), you must delete the resulting output GeoRaster object explicitly in order to roll back the operation.

Usage Notes

This procedure has two formats:

One format generates a GeoRaster object for persistent storage in the database.
The other format generates a BLOB for temporary storage or immediate use, such as to display data on the screen.

This procedure uses a non-parametric rectification method that takes the georeferencing polynomials from the input GeoRaster object to transform the original image space into the georeferencing polynomials given by the outSRS parameter. Therefore, the input GeoRaster object must be georeferenced (see the SDO_GEOR.georeference subprogram).

For more information, see Image Warping.

Examples

In the following example, the output (generated) GeoRaster object will have the same spatial reference system (coordinate system) as outSRS. The input GeoRaster object is a fully georeferenced image.

DECLARE
  srs sdo_geor_srs;
  gr2 sdo_georaster;
  gr3 sdo_georaster;
  gr4 sdo_georaster;
BEGIN
  select georaster into gr2 from georaster_table where georid = 2;
  srs := sdo_geor.getSRS(gr2);
  select georaster into gr3 from georaster_table where georid = 3;

  insert into georaster_table values(4, 'Warped',
         sdo_geor.init('warp_rdt',4)) returning raster into gr4;

  sdo_geor.warp( inGeoRaster      => gr3,
                 pyramidLevel     => null,
                 outSRS           => srs,
                 cropArea         => null,
                 dimensionSize    => sdo_number_array(518,518),
                 layerNumbers     => ‘4,5,3’,
                 elevationParam   => `average=300`,
                 resampleParam    => ‘resampling=AVERAGE4’,
                 storageParam     => ‘pyramid=true’,
                 outGeoRaster     => gr4,
                 bgValues         => sdo_number_array(0,0,0),
                 parallelParam    => ‘parellel=4’ );

  update georaster_table set georaster = gr4 where georid = 4;
  commit;
END;