Changes between Version 62 and Version 63 of WKTRaster/SpecificationWorking03
- Timestamp:
- 04/15/11 08:35:13 (14 years ago)
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WKTRaster/SpecificationWorking03
v62 v63 44 44 Bborie: A complete implementation of ST_Band should include the following: 45 45 46 ST_Band(rast raster, nbands int[]) -> raster46 1. ST_Band(rast raster, nbands int[]) -> raster 47 47 48 48 nbands is an array of 1-based band indices of the bands to copy into the output raster … … 59 59 }}} 60 60 61 ST_Band(rast raster, nband int) -> raster61 2. ST_Band(rast raster, nband int) -> raster 62 62 63 63 nband is a single integer of the 1-based band index of the band to copy into the output raster … … 69 69 }}} 70 70 71 ST_Band(rast raster, nbands text) -> raster71 3. ST_Band(rast raster, nbands text) -> raster 72 72 73 73 nbands is a comma separated string of 1-based band indices indicating the bands to copy into the output raster … … 79 79 }}} 80 80 81 ST_Band(rast raster, nbands text, delimiter char) -> raster81 4. ST_Band(rast raster, nbands text, delimiter char) -> raster 82 82 83 83 nbands is a user-specified delimiter separated string of 1-based band indices indicating the bands to copy into the output raster … … 89 89 }}} 90 90 91 ST_Band(rast raster) -> raster91 5. ST_Band(rast raster) -> raster 92 92 93 93 the band to extract is automatically assumed to be one. … … 105 105 As part of the process to provide complete implementations of ST_AsJPEG and ST_AsPNG, a method is required to reclassify larger numbers unable to be contained in 8BUI (JPEG and PNG) and 16BUI (PNG). For this reclassification function, we need to get the min and max values of a band, thus ST_MinMax. 106 106 107 ST_MinMax(rast raster, nband int) -> record107 1. ST_MinMax(rast raster, nband int) -> record 108 108 109 109 returns one record of two columns (min, max) … … 113 113 }}} 114 114 115 ST_MinMax(rast raster) -> record115 2. ST_MinMax(rast raster) -> record 116 116 117 117 assumes that the band index = 1 … … 211 211 The TIFF format is probably the most robust available for converting rasters to GDAL rasters. Not only does it support all PostGIS Raster pixel types, it also provides plenty of creation options and possibly no issues with the number of bands. The only limitation found is that there can only be one NODATA value for all bands. 212 212 213 ''If the compression parameter/option is specified to JPEG, all bands must be of pixel type 8BUI. If the compression parameter/option is specified to one of the CCITT options, all bands must be of pixel type 1BB.'' 214 213 215 The next three functions are the most basic of the ST_AsTIFF functions. 214 216 … … 344 346 Bborie: this is a generic interface to outputting a supported and installed GDAL raster: 345 347 346 ST_AsGDALRaster(rast raster, format text, options text[], srs text) -> bytea348 1. ST_AsGDALRaster(rast raster, format text, options text[], srs text) -> bytea 347 349 348 350 This is the most generic and GDAL-specific method to convert a raster to a GDAL raster. All other version of ST_AsGDALRaster and other format specific functions (ST_AsJPEG, ST_AsTIFF and ST_AsPNG) are all wrappers around this function. Reference information for the format and options arguments of a particular format are specified at: http://gdal.org/formats_list.html. The arguments specified are: … … 361 363 362 364 363 ST_AsGDALRaster(rast raster, format text, options text[]) -> bytea365 2. ST_AsGDALRaster(rast raster, format text, options text[]) -> bytea 364 366 365 367 This one removes the user-specified srs argument. The output GDAL raster's spatial reference will be set to the same as the input raster, if possible. … … 371 373 }}} 372 374 373 ST_AsGDALRaster(rast raster, format text) -> bytea375 3. ST_AsGDALRaster(rast raster, format text) -> bytea 374 376 375 377 The simplest implementation of this function. Since the options argument has been removed, the output GDAL raster will be created with default options. Like the prior function, the spatial reference of the GDAL raster will be set to the same as the input raster.