Requires an LP360 Geospatial Standard or higher, LP360 Drone, or LP360 Land Standard license.

The Colorize by Image tool on the Tools Tab of the ribbon can be used to colorize point cloud data (LAS) from a raster layer (typically an orthomosaic). It is the updated tool equivalent of the Color by Image PCT. This task will create a new output layer of LAS files, and the source files will remain unchanged.

Figure 1: Colorize LAS Layer by Raster dialog

Input

Available LAS Layers

The source LAS that will be colorized.

Input Raster Layer

The layer (typically an orthomosaic) that contains the images that will be used for colorization.

Note: The Raster Layer must be added prior to opening this tool.

Input Points Filter

This option allows the user to filter the desired points to be considered as input. By default, all points are selected.

Settings

Colorization Settings 

• LIDAR RGB - Checking this box will add RGB fields to the output LAS files. For a regular colored image result set Red to Red Channel, Green to Green Channel, and Blue to Blue Channel. Setting all channels to the same color band will result in a gray scale image.
• LIDAR NIR - Checking this box will add an NIR field to the output LAS files. Creating NIR LAS automatically adds RGB fields to the output LAS since the LAS format only supports RGB or RGB+NIR. The image channel selects which image band is used to populate the NIR LAS attribute.

Interpolation Method

Selects the algorithm that is used to sample the source image when creating the attribute (R, G, B, NIR) that will be used in the output LAS. The options are:

• Bicubic Interpolation: This method uses cubic polynomials to interpolate the pixel values. It is known for producing smoother images compared to simpler methods like bilinear interpolation.
• Bilinear Interpolation: This method uses linear interpolation first in one direction and then again in the other direction. It is faster than bicubic interpolation but may produce less smooth results.
• Lanczos4 Interpolation: This method uses a high-quality resampling filter that can produce sharp images. It is often used for resizing images.
• Nearest Neighbor Interpolation: This is the simplest method where the value of the nearest pixel is assigned to the output pixel. It is fast but can produce blocky images.

Output

LAS Output 

Location where LAS output files are placed.

Output Structure 

Settings allow the output files to be tiled or maintain the file structure of the original input LAS.

Note: When using the Tiled option, the Tile Size must be set. 

Execute

Options for executing the tool on the input LAS Layer(s).

How to Colorize by Image

1. Colorize by Image tool on the Tools Tab of the ribbon will open the Colorize LAS Layer by Raster dialog.
2. Configure the tool:
   • Select LAS Layer(s) to be colorized.
   • Input Raster Layer: Choose the orthophoto or the raster layer that contains the images to be used for colorization.
   • LiDAR RGB: Check this box to add RGB fields to the output LAS files.
     • • Red Image Channel: typically set to 1.
       • Green Image Channel: typically set to 2.
       • Blue Image Channel: typically set to 3.
   • Interpolation Method Recommended: Bilinear
   • LAS Output: Select a folder to save the new LAS files.
   • Output Structure: Choose whether to tile the output files or maintain the original input LAS file structure
3. Select the Execution Method. The colorization process is compute-intensive and may take some time depending on your computer and the size of the project.
4. Review the results by switching your point display to show your points by RGB .