Summary
Reassigns the classification codes and flags of LAS files.
Usage
All LAS files referenced by the LAS dataset will be evaluated by this tool, but only the files that contain the provided class codes will be modified.
Consider using this tool to update the classification of data points in LAS files generated prior to the introduction of standardized class codes in the LAS 1.1 specifications.
The LAS format supports the classification of each point based on the specifications defined by the American Society for Photogrammetry and Remote Sensing (ASPRS). The ArcGIS platform applies the classification scheme specified for LAS file version 1.4:
Classification Value Classification Type 0
Never Classified
1
Unassigned
2
Ground
3
Low Vegetation
4
Medium Vegetation
5
High Vegetation
6
Building
7
Low Noise
8
Model Key / Reserved
9
Water
10
Rail
11
Road Surface
12
Overlap / Reserved
13
Wire – Guard
14
Wire – Conductor
15
Transmission Tower
16
Wire – Connector
17
Bridge Deck
18
High Noise
19 – 63
Reserved for ASPRS Definition (LAS 1.1 to 1.3 support up to class code 31)
32 – 255
User Definable (Only supported in LAS 1.0 and certain versions of 1.4)
Syntax
ChangeLasClassCodes(in_las_dataset, class_codes, {compute_stats}, {extent}, boundary, {process_entire_files})| Parameter | Explanation | Data Type |
in_las_dataset | The LAS dataset to process. | LAS Dataset Layer |
class_codes [[current_class, new_class],...] | Specify each pair of current and new class code values as a space-delimited string or a list of integers. For example, a current class code of 5 can be changed to 2 by specifying "5 2" or [5, 2]. Multiple class codes can be entered as a semicolon-delimited string ("5 2; 8 3; 1 4"), a list of strings (for example, [[5, 2], [8, 3], [1, 4]]). | Value Table |
compute_stats (Optional) | Specifies whether statistics should be computed for the LAS files referenced by the LAS dataset. Computing statistics provides a spatial index for each LAS file, which improves analysis and display performance. Statistics also enhance the filtering and symbology experience by limiting the display of LAS attributes, like classification codes and return information, to values that are present in the LAS file.
| Boolean |
extent (Optional) | Specifies the extent of the data that will be evaluated by this tool. | Extent |
boundary | A polygon feature that defines the area of interest to be processed by this tool. | Feature Layer |
process_entire_files (Optional) | Specifies how the processing extent is applied.
| Boolean |
Derived Output
| Name | Explanation | Data Type |
| derived_las_dataset | The updated LAS dataset. | LAS Dataset Layer |
Code sample
The following sample demonstrates the use of this tool in the Python window.
arcpy.env.workspace = 'C:/data'
arcpy.ChangeLasClassCodes_3d('test.lasd', [[5, 2], [3, 1], [4, 6]],
'COMPUTE_STATS')The following sample demonstrates the use of this tool in a stand-alone Python script.
'''****************************************************************************
Name: Update LAS 1.0 Classification to ASPRS 1.1 Specs
Description: Updates classification of version 1.0 LAS files to conform to
the standardized class codes introduced in the 1.1 specifications.
The code is designed for use as a script tool.
****************************************************************************'''
# Import system modules
import arcpy
# Set Local Variables
inLas = arcpy.GetParameterAsText(0)
recursion = arcpy.GetParameterAsText(1)
lasd = arcpy.GetParameterAsText(2)
reclassList = arcpy.GetParameterAsText(3) #List of values '<oldCode> <newCode>'
calcStats = arcpy.GetParameter(4)
# Execute CreateLasDataset
arcpy.management.CreateLasDataset(inLas, lasd, recursion)
# Execute ChangeLasClassCodes
arcpy.ddd.ChangeLasClassCodes(lasd, reclassList, calcStats)Environments
Licensing information
- Basic: Requires 3D Analyst
- Standard: Requires 3D Analyst
- Advanced: Requires 3D Analyst