Summary
Classifies building rooftop points in aerial lidar data.
Usage
The lidar data must have ground points that are assigned a class code value of 2. If ground points are assigned a different value, use the Change LAS Class Codes tool to reassign the ground points to 2. If ground points have not been classified, consider using the Classify LAS Ground tool.
Lidar points with class code values of 0 and 1 will be evaluated to determine if they fit the spatial criteria that is used for identifying LAS points that represent buildings. Existing building classified points with a class code value of 6 will also be used to determine if adjacent points contribute to the same structure.
If commission errors, or points that do not belong to buildings, are found after processing lidar data with this tool, consider increasing the value specified for the Minimum Area parameter to eliminate the inclusion of such points. If buildings appear to have been missed by the tool, consider using a smaller value to obtain better results.
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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
ClassifyLasBuilding_3d (in_las_dataset, {min_height}, min_area, {compute_stats}, {extent}, boundary, {process_entire_files})| Parameter | Explanation | Data Type |
in_las_dataset | The LAS dataset to be classified. | LAS Dataset Layer |
min_height (Optional) | The height from the ground that defines the lowest point from which rooftop points will be identified. | Linear unit |
min_area | The smallest area of coverage that will establish the initial classification of building points. Once an initial detection has been made, the data will be processed to identify adjacent features that may be smaller than the area specified for this parameter. | Areal Unit |
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.
| Boolean |
extent (Optional) | Specify the extent of the data that will be evaluated by this tool. | Extent |
boundary | A polygon feature that defines the area of interest that will be processed by this tool. | Feature Layer |
process_entire_files (Optional) | Specify how the processing extent is applied.
| Boolean |
Code sample
ClassifyLasBuilding example 1 (Python window)
The following sample demonstrates the use of this tool in the Python window.
arcpy.env.workspace = 'C:/data'
arcpy.ClassifyLasBuilding_3d('Highland.lasd', minHeight='9 feet',
minArea='30 Square Feet', compute_stats=True)
ClassifyLasBuilding example 2 (stand-alone script)
The following sample demonstrates the use of this tool in a stand-alone Python script.
Missing source code file
Environments
Licensing information
- ArcGIS Desktop Basic: Requires 3D Analyst
- ArcGIS Desktop Standard: Requires 3D Analyst
- ArcGIS Desktop Advanced: Requires 3D Analyst