Point Cloud Preprocessing
Before object recognition, you need to preprocess the data by adjusting the parameters to make the original point cloud clearer, thus improving the recognition accuracy and efficiency.
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Except for the “Set recognition region,” the parameters in the “Point cloud preprocessing” process are valid for all target objects in the “3D Target Object Recognition” tool. In other words, once the parameters are adjusted, the preprocessing results of all target objects will change accordingly. If you want to use different point cloud preprocessing methods for different target objects, you can add multiple “3D Target Object Recognition” Steps to the project to set different point cloud preprocessing parameters for different objects to achieve different point cloud preprocessing results. |
Set Recognition Region (3D ROI)
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Click Set and set a 3D ROI in the ROI setting window.
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After the setting, click Save and apply.
Then, you can click Run Step to view the preprocessing results in the visualization area on the left.
Adjust Parameters
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By default, only the Edge extraction effect parameter will be displayed. If you need to adjust more parameters, you can enable View more parameters. Among the following parameters, Edge extraction effect and Noise removal level are valid for both edge and surface point clouds, while other parameters are only valid for surface point clouds. |
- Edge extraction effect
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Description: Use this parameter to determine the edge extraction effect.
Value list: Fine, Standard, Rough, Extra rough, Custom
Instruction: Set this parameter according to the actual requirement. In general, select Standard. When Custom is selected, you need to set the normal variation threshold in degrees (°) for determining edge points. A point is considered an edge point if the normal variations of its neighboring points are above this threshold. By normal variation means a comprehensive value considering the normal variation of the neighboring points.
- Noise removal level
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Description: Use this parameter to determine the noise removal level.
Value list: None, Weak, Strong
Instruction: Set the parameter according to the actual requirement.
Point filter
- Min polar angle
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Description: Use this parameter to determine the lower limit of the angular difference in degrees (°) in the process of point filtering. When the polar angle is lower than this value, the point will be filtered out.
Default value: 0°
- Max polar angle
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Description: Use this parameter to determine the upper limit of the angular difference in degrees (°) in the process of point filtering. When the max polar angle is above this value, the point will be filtered out.
Default value: 70°
Remove noise by clustering
- Cluster radius
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Default value: 3.000 mm
Description: Use this parameter to determine the radius in millimeters (mm) for clustering.
Instruction: When this parameter is large, points that are far apart will be grouped into the same cluster; when this value is small, points that are close together will be grouped into different clusters.
- Min point count per cluster
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Description: This parameter is for filtering the results after clustering. Only the classes with the number of points greater than the minimum point count can be output. When this parameter is large, the number of output classes will decrease; when the parameter is small, the number of output classes will increase.
Default value: 100
- Max point count per cluster
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Description: This parameter is for filtering the results after clustering. Only the classes with the number of points lower than the maximum point count can be output. When this parameter is large, the number of output classes will increase; when the parameter is small, the number of output classes will decrease.
Default value: 3000000
Point cloud display settings
You can set the display mode of point clouds according to the actual requirement to one of the following: Display all point clouds, Display surface point cloud only, Display edge point cloud only.
View preprocessing result
After setting the above parameters, click Run Step or Run project to view the preprocessing result.
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To view other results after preprocessing, you can switch relevant options at the top of the tool interface. |
After point cloud preprocessing, click Next to enter the “Target object selection and recognition” process.