readers.gdal#
The GDAL reader reads GDAL readable raster data sources as point clouds.
Each pixel is given an X and Y coordinate (and corresponding PDAL dimensions) that are center pixel, and each band is represented by “band-1”, “band-2”, or “band-n”. Using the ‘header’ option allows naming the band data to standard PDAL dimensions.
Basic Example#
Simply writing every pixel of a JPEG to a text file is not very useful.
[
{
"type":"readers.gdal",
"filename":"./pdal/test/data/autzen/autzen.jpg"
},
{
"type":"writers.text",
"filename":"outputfile.txt"
}
]
LAS Example#
The following example assigns the bands from a JPG to the RGB values of an ASPRS LAS file using writers.las.
[
{
"type":"readers.gdal",
"filename":"./pdal/test/data/autzen/autzen.jpg",
"header": "Red, Green, Blue"
},
{
"type":"writers.las",
"filename":"outputfile.las"
}
]
Note
readers.gdal is quite sensitive to GDAL’s cache settings. See the
GDAL_CACHEMAX
value at https://gdal.org/user/configoptions.html for
more information.
Options#
- filename
GDALOpen ‘able raster file to read [Required]
- count
Maximum number of points to read. [Default: unlimited]
- override_srs
Spatial reference to apply to the data. Overrides any SRS in the input itself. Can be specified as a WKT, PROJ or EPSG string. Can’t use with ‘default_srs’. [Default: none]
- default_srs
Spatial reference to apply to the data if the input does not specify one. Can be specified as a WKT, PROJ or EPSG string. Can’t use with ‘override_srs’. [Default: none]
- header
A comma-separated list of dimension IDs to map bands to. The length of the list must match the number of bands in the raster.
- memorycopy
Use the GDAL MEM driver to copy the entire raster into memory before converting to points. This is useful if the raster driver has a lot of per-block overhead or you are willing to trade memory for performance.
- gdalopts
A list of key/value options to pass directly to the GDAL driver. The format is name=value,name=value,… The option may be specified any number of times.