Header

mutable struct LasHeader

A LAS Header containing metadata regarding information in a LAS file See full specification here

• las_version::VersionNumber: The LAS spec version this header was written in

• file_source_id::UInt16: Numeric identifier for the source that made this file. Set to 0 if the ID is unassigned

• global_encoding::UInt16: A bit field used to indicate global properties. See the spec for more info

• guid_1::UInt32: First member of the Project GUID

• guid_2::UInt16: Second member of the Project GUID

• guid_3::UInt16: Third member of the Project GUID

• guid_4::NTuple{8, UInt8}: Fourth member of the Project GUID

• system_id::NTuple{32, UInt8}: A unique identifier indicating how the data was created

• software_id::NTuple{32, UInt8}: Identifier for the software that created the LAS file

• creation_dayofyear::UInt16: The Greenwich Mean Time (GMT) day of the year (as an unsigned short) on which the file was created

• creation_year::UInt16: Four digit number for the year the file was created

• header_size::UInt16: Size (in bytes) of the public header block in the LAS file. This varies depending on which LAS version was used to write it. For LAS v1.4 it's 375 bytes

• data_offset::UInt32: Offset to the point data (in bytes) from the start of the file to the first field of the first point record

• n_vlr::UInt32: Number of Variable Length Records (VLR's) in the LAS file. These come after the header and before the point records

• data_format_id::UInt8: Point data record format stored in the LAS file. LAS v1.4 supports formats 0-10

• data_record_length::UInt16: Size in bytes of a point data record

• legacy_record_count::UInt32: For maintaining legacy compatibility, the number of point records in the file (must not exceed typemax(UInt32)). Only populated for point records 0-5

• legacy_point_return_count::NTuple{5, UInt32}: For maintaining legacy compatibility, the number of points per return (max of 5 returns, counts must not exceed typemax(UInt32)). Only populated for point records 0-5

• spatial_info::SpatialInfo: Spatial information describing the bounding range of the points, their offsets and any scaling factor applied to them

• waveform_record_start::UInt64: Offset in bytes from the start of the file to the first byte of the Waveform Data Package Reckord

• evlr_start::UInt64: Offset in bytes from the start of the file to the first byte of the first Extended Variable Length Record (EVLR)

• n_evlr::UInt32: Number of EVLR's in the LAS file

• record_count::UInt64: Number of point records saved in this file (can't exceed typemax(UInt64)). This is populated for LAS v1.4

• point_return_count::NTuple{15, UInt64}: Number of points per return saved in this file (15 returns total, counts can't exceed typemax(UInt64)). This is populated for LAS v1.4

las_version(h::LasHeader) -> VersionNumber

Get the LAS specification version from a header h

file_source_id(h::LasHeader) -> UInt16

Get the file source ID specification version from a header h

global_encoding(h::LasHeader) -> UInt16

Get the global properties bit vector from a header h

system_id(h::LasHeader) -> String

Get the system ID from a header h

software_id(h::LasHeader) -> String

Get the software ID from a header h

creation_day_of_year(h::LasHeader) -> UInt16

Get the creation day of the year from a header h

creation_year(h::LasHeader) -> UInt16

Get the creation year from a header h

header_size(h::LasHeader) -> Int64

Get the size of a header h in bytes

point_data_offset(h::LasHeader) -> Int64

Get the offset to the first point record in a LAS file specified by a header h

point_record_length(h::LasHeader) -> Int64

Get the number of bytes assigned to each point record in a LAS file specified by a header h

point_format(header::LasHeader) -> Any

Get the LAS point format from a header header

number_of_points(h::LasHeader) -> Int64

Get the number of points in a LAS file from a header h

get_number_of_points_by_return(
    header::LasHeader
) -> Union{NTuple{5, UInt32}, NTuple{15, UInt64}}

Get the number of points per return for a header header

number_of_vlrs(h::LasHeader) -> Int64

Get the number of Variable Length Records in a LAS file from a header h

number_of_evlrs(h::LasHeader) -> Int64

Get the number of Extended Variable Length Records in a LAS file from a header h

evlr_start(header::LasHeader) -> UInt64

Get the offset in bytes to the first EVLR in a LAS file from a header header

spatial_info(h::LasHeader) -> SpatialInfo

Get the spatial information for point positions in a LAS file from a header h. This includes the offsets/scale factors applied to points and bounding box information

num_return_channels(h::LasHeader) -> Int64

Get the number of return channels in a LAS file from a header h

If true, GPS Time is standard GPS Time (satellite GPS Time) minus 1e9. If false, GPS Time is GPS Week Time.

Note that not all software sets this encoding correctly.

Check if the projection information is in WKT format (true) or GeoTIFF (false)

is_internal_waveform(header::LasHeader) -> Bool

Returns whether a LAS file with header header has waveform data stored in the LAS file

is_external_waveform(header::LasHeader) -> Bool

Returns whether a LAS file with header header has waveform data in an external file

waveform_record_start(header::LasHeader) -> UInt64

Get the offset in bytes to the first waveform record for a LAS file with header header

set_las_version!(h::LasHeader, v::VersionNumber)

Set the LAS specification version in a header h to version v

set_point_format!(h::LasHeader, _::Type{TPoint<:LasPoint})

Set the point format in a header h to a new value, TPoint

set_spatial_info!(
    header::LasHeader,
    info::SpatialInfo
) -> SpatialInfo

Set the spatial information associated to points in a LAS file with a header header

set_point_data_offset!(
    header::LasHeader,
    offset::Integer
) -> UInt32

Set offset to the first point record in a LAS file with a header header

set_point_record_length!(
    header::LasHeader,
    length::Integer
) -> UInt16

Set the number of bytes associated to each point record in a LAS file with a header header

set_point_record_count!(
    header::LasHeader,
    num_points::Integer
)

Set the number of points in a LAS file with a header header

set_num_vlr!(header::LasHeader, n::Integer) -> UInt64

Set the number of Variable Length Records in a LAS file with a header header

set_num_evlr!(header::LasHeader, n::Integer) -> UInt64

Set the number of Extended Variable Length Records in a LAS file with a header header

set_gps_week_time_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the header header is in GPS week time

set_gps_standard_time_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the header header is in GPS standard time

set_waveform_internal_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the header header has internal waveform records

set_waveform_external_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the header header has external waveform records

set_synthetic_return_numbers_bit!(
    header::LasHeader
) -> UInt16

Sets the bit flag indicating that the header header has synthetically-generated return numbers

unset_synthetic_return_numbers_bit!(
    header::LasHeader
) -> UInt16

Sets the bit flag indicating that the header header does not have synthetically-generated return numbers

set_wkt_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the LAS file with header header has its coordinate reference system set as a WKT

unset_wkt_bit!(header::LasHeader) -> UInt16

Sets the bit flag indicating that the LAS file with header header doesn't have its coordinate reference system set as a WKT

set_number_of_points_by_return!(
    header::LasHeader,
    points_per_return::NTuple{N, Integer}
)

Set the number of points per return for a header header to the values points_per_return