filters.reprojection¶
The reprojection filter converts the X, Y and/or Z dimensions to a new spatial reference system. The old coordinates are replaced by the new ones, if you want to preserve the old coordinates for future processing, use a filters.ferry to create a new dimension and stuff them there.
Note
X, Y, and Z dimensions in PDAL are carried as doubles, with their scale information applied. Set the output scale (scale_x, scale_y, or scale_z) on your writer to descale the data on the way out.
Many LIDAR formats store coordinate information in 32-bit address spaces, and use scaling and offsetting to ensure that accuracy is not lost while fitting the information into a limited address space. When changing projections, the coordinate values will change, which may change the optimal scale and offset for storing the data.
Example¶
{
"pipeline":[
{
"filename":"input.las",
"type":"readers.las",
"spatialreference":"EPSG:26916"
},
{
"type":"filters.range",
"limits":"Z[0:100],Classification[2:2]"
},
{
"type":"filters.reprojection",
"in_srs":"EPSG:26916",
"out_srs":"EPSG:4326"
},
{
"type":"writers.las",
"scale_x":"0.0000001",
"scale_y":"0.0000001",
"scale_z":"0.01",
"offset_x":"auto",
"offset_y":"auto",
"offset_z":"auto",
"filename":"example-geog.las"
}
]
}
Options¶
- in_srs
- Spatial reference system of the input data. Express as an EPSG string (eg “EPSG:4326” for WGS86 geographic) or a well-known text string. [Required if input reader does not supply SRS information]
- out_srs
- Spatial reference system of the output data. Express as an EPSG string (eg “EPSG:4326” for WGS86 geographic) or a well-known text string. [Required]