RAS2LAZ

Description

RAS2LAZ first converts, and then exports, a raster digital elevation model (DEM) and optionally, imagery to a point cloud in LASzip Compressed Lidar Data (LAZ) format (.laz) .

Parameters

ras2laz(filedem, dbec, dbimage, filo, foptions)

Name	Type	Caption	Length	Value range
FILEDEM *	str	Geocoded DEM file to export	1 -
DBEC *	List[int]	Input DSM channel	1 - 1
DBIMAGE	List[int]	Optional image (color) bands to include	0 - 3
FILO *	str	Name of output file to create	1 -
FOPTIONS	str	Output file options	0 - 64

* Required parameter

Parameter descriptions

FILEDEM

The path and name of the file containg the DEM and, optionally, imagery, to export.

DBEC

The input channel that contains the digital surface model (DSM) or DEM to export.

DBIMAGE

The image (color) bands to include in the output file.

Each exported DEM point will be colored with its corresponding imagery bands. If you specify a single band the result will be black and white. If you specify three bands they are considered red, blue, and green (RGB).

16U imagery values are written as is. 8U data by default is scaled to 16bit. The scaling can be turned off using the FOPTIONS parameter.

FILO

The name of the output file (.laz) to create as a point cloud.

The file name you specify must not exist in the folder. The projection of the output file will be that of the input file.

FOPTIONS

Specifies the file creation options that are to be applied when creating the output file. These are specific to the file format; the default of no options is allowed. FOPTIONS can be used to specify the colorization method when using an 8 bit raster. The default is that 8 bit raster values are multiplied by 256 before passing the resulting 16 bit color value to the laszip library. Using the NOSCALE option means that the 8 bit raster values are not multiplied by 256.

Details

RAS2LAZ exports a raster DEM to a point-cloud file in LAZ format (.laz). With the LAZ format, each point can be colored using its corresponding imagery according to the color bands you specify.

Imagery data is exported as is.

If you want to apply any enhancements to the imagery, you must must do so directly before running RAS2LAZ. For example, you can apply a lookup table (LUT) in CATALYST Professional Focus.

When exporting to LAZ, 8-bit imagery by default is converted automatically to 16-bit by multiplying by 256. This behavior can be overridden by specifying FOPTIONS="NOSCALE".

When displayed in a point-cloud viewer, the imagery may have a dull, dark, or washed-out appearance.

Elevation values that are NoData (per the NO_DATA_VALUE metadata tag) are not included in the geocoded DEM file to export.

The LAZ format uses file compresssion.

Example

You have a file (dsm.pix) containing a DEM in band 1 and corregistered RGB imagery in bands 2, 3, and 4 and want to export it to a point-cloud file in LAZ format.

from pci.ras2laz import ras2laz

filedem  = r"dsm.pix"
dbec     = [1]
dbimage  = [2,3,4]
filo     = r"pointcloud.laz"

ras2laz(filedem, dbimage, dbec, filo)