filters.ferry

The ferry filter is used to stash intermediate variables as part of processing data. For example, a common scenario is to keep both the original value and the reprojected X and Y variables in a scenario that uses the filters.reprojection filter. In the normal case, the X and Y data would be overwritten with the new longitude and latitude values as part of the reprojection. The ferry filter will allow you to keep this around for later use.

Example

In this scenario, we are doing what is described above – stashing the pre-projection X and Y values into the StatePlaneX and StatePlaneY dimensions. Future processing, can then operate on these data.

{
  "pipeline":[
    "uncompressed.las",
    {
      "type":"readers.las",
      "spatialreference":"EPSG:2993",
      "filename":"../las/1.2-with-color.las"
    },
    {
      "type":"filters.ferry",
      "dimensions":"X = StatePlaneX, Y=StatePlaneY"
    },
    {
      "type":"filters.reprojection",
      "out_srs":"EPSG:4326+4326"
    },
    {
      "type":"writers.las",
      "scale_x":"0.0000001",
      "scale_y":"0.0000001",
      "filename":"colorized.las"
    }
  ]
}

Options

dimensions
A list of dimensions whose values should be copied to the specified dimensions. The format of the option is <from>=<to>, <from>=<to>,... Spaces are ignored. ‘from’ dimensions must exist and have been created by a reader or filter. ‘to’ dimensions will be created if necessary.