PostGIS
Name
ST_AsTIFF — Return the raster selected bands as a single TIFF image (byte array). If no band is specified or any of specified bands does not exist in the raster, then will try to use all bands.
Synopsis
bytea +`*`+ST_AsTIFF*(`raster `rast, text[] options='',
integer srid=sameassource`)`;
bytea +`*`+ST_AsTIFF*(`raster `rast, text compression='',
integer srid=sameassource`)`;
bytea +`*`+ST_AsTIFF*(`raster `rast, integer[] nbands,
text compression='', integer srid=sameassource`)`;
bytea +`*`+ST_AsTIFF*(`raster `rast, integer[] nbands,
text[] options, integer srid=sameassource`)`;
Description
Returns the selected bands of the raster as a single Tagged Image File Format (TIFF). If no band is specified, will try to use all bands. This is a wrapper around ST_AsGDALRaster. Use ST_AsGDALRaster if you need to export as less common raster types. There are many variants of the function with many options. If no spatial reference SRS text is present, the spatial reference of the raster is used. These are itemized below:
-
nbandsis an array of bands to export (note that max is 3 for PNG) and the order of the bands is RGB. e.g ARRAY[3,2,1] means map band 3 to Red, band 2 to green and band 1 to blue -
compressionCompression expression — JPEG90 (or some other percent), LZW, JPEG, DEFLATE9. -
optionstext Array of GDAL create options as defined for GTiff (look at create_options for GTiff of ST_GDALDrivers). or refer to GDAL Raster format options for more details. -
sridsrid of spatial_ref_sys of the raster. This is used to populate the georeference information
Availability: 2.0.0 - requires GDAL >= 1.6.0.
Examples: Use jpeg compression 90%
SELECT ST_AsTIFF(rast, 'JPEG90') As rasttiff
FROM dummy_rast WHERE rid=2;