filters.smrf¶
Filter ground returns using the Simple Morphological Filter (SMRF) approach outlined in [Pingel2013].
Example #1¶
The sample pipeline below uses filters.smrf
to segment ground and non-ground
returns, using default options, and writing only the ground returns to the
output file.
{
"pipeline":[
"input.las",
{
"type":"filters.smrf"
},
{
"type":"filters.range",
"limits":"Classification[2:2]"
},
"output.laz"
]
}
Example #2¶
A more complete example, specifying some options. These match the optimized parameters for Sample 1 given in Table 3 of [Pingel2013].
{
"pipeline":[
"input.las",
{
"type":"filters.smrf",
"scalar":1.2,
"slope":0.2,
"threshold":0.45,
"window":16.0
},
{
"type":"filters.range",
"limits":"Classification[2:2]"
}
"output.laz"
]
}
Options¶
- cell
- Cell size. [Default: 1.0]
- cut
- Cut net size (
cut=0
skips the net cutting step). [Default: 0.0] - dir
- Optional output directory for debugging intermediate rasters.
- ignore
- A range of values of a dimension to ignore.
- returns
- Return types to include in output. Valid values are “first”, “last”, “intermediate” and “only”. [Default: “last, only”]
- scalar
- Elevation scalar. [Default: 1.25]
- slope
- Slope (rise over run). [Default: 0.15]
- threshold
- Elevation threshold. [Default: 0.5]
- window
- Max window size. [Default: 18.0]