Change LAS Class Codes—Help | ArcGIS for Desktop

Available with 3D Analyst license.

Summary
Usage
Syntax
Code Sample
Environments
Licensing Information

Summary

Modifies the class code values of LAS files referenced by a LAS dataset.

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_3d (in_las_dataset, class_codes, {compute_stats})

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. The presence of statistics allows the LAS dataset layer's filtering and symbology options to only show LAS attribute values that exist in the LAS files. COMPUTE_STATS —Statistics will be computed. NO_COMPUTE_STATS —Statistics will not be computed. This is the default.	Boolean

Code Sample

ChangeLasClassCodes example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window.

import arcpy
from arcpy import env

arcpy.CheckOutExtension('3D')
env.workspace = 'C:/data'
arcpy.ChangeLasClassCodes_3d('test.lasd', [[5, 2], [3, 1], [4, 6]], 
                           'COMPUTE_STATS')

ChangeLasClassCodes example 2 (stand-alone script)

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
import exceptions, sys, traceback

# 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)

try:
    arcpy.CheckOutExtension('3D')
    # Execute CreateLasDataset
    arcpy.management.CreateLasDataset(inLas, lasd, recursion)
    # Execute ChangeLasClassCodes
    arcpy.ddd.ChangeLasClassCodes(lasd, reclassList, calcStats)
    # Report messages
    arcpy.GetMessages()
    
except arcpy.ExecuteError:
    print arcpy.GetMessages()
    
except:
    # Get the traceback object
    tb = sys.exc_info()[2]
    tbinfo = traceback.format_tb(tb)[0]
    # Concatenate error information into message string
    pymsg = 'PYTHON ERRORS:\nTraceback info:\n{0}\nError Info:\n{1}'\
          .format(tbinfo, str(sys.exc_info()[1]))
    msgs = 'ArcPy ERRORS:\n {0}\n'.format(arcpy.GetMessages(2))
    # Return python error messages for script tool or Python Window
    arcpy.AddError(pymsg)
    arcpy.AddError(msgs)

Environments

Current Workspace

Licensing Information

ArcGIS for Desktop Basic: Requires 3D Analyst
ArcGIS for Desktop Standard: Requires 3D Analyst
ArcGIS for Desktop Advanced: Requires 3D Analyst