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rosReadRGB

Extract RGB color values from ROS or ROS 2 point cloud message structure

Since R2021a

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Syntax

rgb = rosReadRGB(pcloud)
rgb = rosReadRGB(pcloud,"PreserveStructureOnRead",true)
fielddata = rosReadRGB(pcloud,"Datatype","double")

Description

rgb = rosReadRGB(pcloud) extracts the [r g b] values from all points in the ROS or ROS 2 'sensor_msgs/PointCloud2' message structure, pcloud, and returns them as an n-by-3 matrix of n 3-D point coordinates.

rgb = rosReadRGB(pcloud,"PreserveStructureOnRead",true) preserves the organizational structure of the point cloud returned in the rgb output. For more information, see Preserving Point Cloud Structure.

fielddata = rosReadRGB(pcloud,"Datatype","double") reads the [r g b] data in double precision during code generation. If you use this syntax for MATLAB® execution, the function always reads the data in the precision specified by the corresponding field in the input message structure, pcloud.

Input Arguments

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Point cloud, specified as a message structure for ROS or ROS 2 'sensor_msgs/PointCloud2' message.

Output Arguments

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List of RGB values from point cloud, returned as a matrix. By default, this is a n-by-3 matrix.

If the PreserveStructureOnRead name-value pair argument is set to true, the points are returned as an h-by-w-by-3 matrix.

Tips

Point cloud data can be organized in either 1-D lists or in 2-D image styles. 2-D image styles usually come from depth sensors or stereo cameras. The input PointCloud2 object contains a PreserveStructureOnRead property that is either true or false (default). Suppose you set the property to true.

pcloud.PreserveStructureOnRead = true;

Now calling any read functions (rosReadXYZ, rosReadRGB, or rosReadField) preserves the organizational structure of the point cloud. When you preserve the structure, the output matrices are of size m-by-n-by-d, where m is the height, n is the width, and d is the number of return values for each point. Otherwise, all points are returned as a x-by-d list. This structure can be preserved only if the point cloud is organized.

Extended Capabilities

Version History

Introduced in R2021a

See Also

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