Change LAS Class Codes (3D Analyst)

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.

  • ArcGIS uses the LAS classification scheme defined by the American Society for Photogrammetry and Remote Sensing (ASPRS). Learn more about lidar point classification

    Classification value Meaning

    0

    Created, Never classified

    1

    Unassigned

    2

    Ground

    3

    Low Vegetation

    4

    Medium Vegetation

    5

    High Vegetation

    6

    Building

    7

    Low Point

    8

    Model Key-Point

    9

    Water

    10

    Rail

    11

    Road Surface

    12

    Reserved

    13

    Wire - Guard (Shield)

    14

    Wire - Conductor (Phase)

    15

    Transmission Tower

    16

    Wire-Structure Connector (Insulator)

    17

    Bridge Deck

    18

    High Noise

    19

    Reserved

    20

    Ignored Ground

    21

    Snow

    22

    Temporal Exclusion

    23–63

    Reserved

    64–255

    User Definable

    Note:
    • The most current LAS 1.4 classification system has these codes (code 8: Model Key/Reserved and code 12: Overlap/Reserved) reserved, and points with these characteristics should use the corresponding class flags instead.
    • LAS 1.1–1.3 only support classes 0–31.

Parameters

LabelExplanationData Type
Input LAS Dataset

The LAS dataset that will be processed.

LAS Dataset Layer
Class Codes

Specifies the list of existing class codes to be modified and the change that will be made to its respective classification code value and classification flags.

Value Table
Compute statistics
(Optional)

Specifies whether statistics will 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, such as classification codes and return information, to values that are present in the .las file.

  • Checked—Statistics will be computed. This is the default.
  • Unchecked—Statistics will not be computed.
Boolean
Processing Extent
(Optional)

The extent of the data that will be evaluated.

  • Current Display Extent Current Display Extent—The extent will be based on the active map or scene. This option is only available when there is an active map.
  • Draw Extent Draw Extent—The extent will be based on a rectangle drawn on the map or scene. This option will create a feature class in the project geodatabase and add a layer to the map. The feature class will have the same coordinate system as the map.
    Note:

    This option is not available in the Environments dialog box. It is only available from a tool parameter with an extent data type or from the Environments tab on a tool dialog box.

    Note:

    When the Enable and disable editing from the Edit tab editing option is checked, you must enable editing on the Edit ribbon tab to draw the extent.

  • Extent of a Layer Layer—The extent will be based on an active map layer. Use the drop-down list to choose an available layer or use the Extent of data in all layers option to get the combined extent of all active map layers, excluding the basemap. This option is only available when there is an active map with layers.

    Each map layer has the following options:

    • All Features Select All—The extent of all features in the layer.
    • Selected Features Area from Selected Features—The extent of the selected features in the layer.
    • Visible Features Extent Indicator—The extent of visible features in the layer.
      Note:

      The extents from the Selected Features Area from Selected Features and Visible Features Extent Indicator options are only available for feature layers.

  • Browse Browse—The extent will be based on an existing dataset.
  • Intersection of Inputs Intersect—The extent will be based on the minimum or intersecting extent of all inputs. If no inputs overlap, a null extent with all zeros will result.
  • Union of Inputs Union—The extent will be based on the maximum or combined extent of all inputs.
  • Clipboard Paste—The extent can be copied to and from the clipboard.
    • Copy Extent Copy—Copies the extent coordinates and coordinate system to the clipboard.
    • Paste Extent Paste—Pastes the extent coordinates and, optionally, the coordinate system from the clipboard. If the clipboard values do not include a coordinate system, the extent will use the map’s coordinate system.
    Note:

    The extent coordinates are copied to and pasted from the clipboard using the same formatting and order as the ArcPy Extent object: x-min, y-min, x-max, y-max, and the spatial reference.

  • Reset Extent Reset—The extent will be reset to the default value.
  • Manually entered coordinates—The coordinates must be numeric values and in the active map's coordinate system.
    Caution:

    The map may use different display units than the entered coordinates. The use of a cardinal direction (N, S, E, W) is not supported. Use a negative value sign for south and west coordinates.

Extent
Processing Boundary

A polygon feature that will define the area of interest to be processed.

Feature Layer
Process entire LAS files that intersect extent
(Optional)

Specifies how the area of interest will be used in determining how .las files will be processed. The area of interest is defined by the Processing Extent parameter value, the Processing Boundary parameter value, or a combination of both.

  • Unchecked—Only LAS points that intersect the area of interest will be processed. This is the default.
  • Checked—If any portion of a .las file intersects the area of interest, all the points in that file, including those outside the area of interest, will be processed.
Boolean
Update pyramid
(Optional)

Specifies whether the LAS dataset pyramid will be updated after the class codes are modified.

  • Checked—The LAS dataset pyramid will be updated. This is the default.
  • Unchecked—The LAS dataset pyramid will not be updated.
Boolean

Derived Output

LabelExplanationData Type
Output LAS Dataset

The updated LAS dataset.

LAS Dataset Layer

arcpy.ddd.ChangeLasClassCodes(in_las_dataset, class_codes, {compute_stats}, {extent}, boundary, {process_entire_files}, {update_pyramid})
NameExplanationData Type
in_las_dataset

The LAS dataset that will be processed.

LAS Dataset Layer
class_codes
[[current_class, new_class],...]

Specifies the list of existing class codes to be modified and the change that will be made to its respective classification code value and classification flags.

The existing class code, the new class code, and the new class flag can be represented as a space-delimited string or a list of lists containing the values to be reclassified. For example, a current class code of 5 can be changed to 25 by specifying "5 2" or [[5, 2]]. Likewise, a change to the synthetic class flag can be made by adding the keyword for the desired modification ("5 2 SET" or [[5, 2, "SET"]]). Multiple changes can be specified as a semicolon-delimited string (for example, "5 2; 8 3; 1 4") or as a list of lists (for example, [[5, 2], [8, 3], [1, 4]]).

Value Table
compute_stats
(Optional)

Specifies whether statistics will 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, such as classification codes and return information, to values that are present in the .las file.

  • COMPUTE_STATSStatistics will be computed. This is the default.
  • NO_COMPUTE_STATSStatistics will not be computed.
Boolean
extent
(Optional)

The extent of the data that will be evaluated.

  • MAXOF—The maximum extent of all inputs will be used.
  • MINOF—The minimum area common to all inputs will be used.
  • DISPLAY—The extent is equal to the visible display.
  • Layer name—The extent of the specified layer will be used.
  • Extent object—The extent of the specified object will be used.
  • Space delimited string of coordinates—The extent of the specified string will be used. Coordinates are expressed in the order of x-min, y-min, x-max, y-max.
Extent
boundary

A polygon feature that will define the area of interest to be processed.

Feature Layer
process_entire_files
(Optional)

Specifies how the processing extent will be applied.

  • PROCESS_EXTENTOnly LAS points that intersect the area of interest will be processed. This is the default.
  • PROCESS_ENTIRE_FILESIf any portion of a .las file intersects the area of interest, all the points in that file, including those outside the area of interest, will be processed.
Boolean
update_pyramid
(Optional)

Specifies whether the LAS dataset pyramid will be updated after the class codes are modified.

  • UPDATE_PYRAMIDThe LAS dataset pyramid will be updated. This is the default.
  • NO_UPDATE_PYRAMIDThe LAS dataset pyramid will not be updated.
Boolean

Derived Output

NameExplanationData Type
derived_las_dataset

The updated LAS dataset.

LAS Dataset Layer

Code sample

ChangeLasClassCodes example 1 (Python window)

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

arcpy.env.workspace = 'C:/data'
arcpy.ddd.ChangeLasClassCodes('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

# 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)

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