Exclude 3D information based on color¶
The color filter can be used to explicitly include or exclude points with a certain color. Several use cases for the color filter are:
- Excluding parts of a bin
- Detection of thin parts on a flat surface
The color filter is a light dependent solution. This requires very stable light conditions (same illumination, no changing shadows) for reproducible results.
Example of detecting thin parts on a flat surface¶
This is an example case where we want to detect thin parts at the bottom of a bin. Since these parts are very thin, their 3D shape does not stand out from the bin bottom, as their thickness is smaller than the noise levels of the cloud. It is therefore impossible to define the ROI box dimensions such that only points from the parts are included, without any points from the bin.
1. Define your ROI¶
When building the ROI box without the color filter, we can see 2 problems:
- We still see some parts of the bottom in the Points view
- The point cloud of our parts is not very good.
When dealing with parts that are not as thin as these, we can increase the Z-min of the ROI to remove the bottom, or lower the Z-min to make the parts more visible.
2. Lower the Z-min of the ROI¶
We lower the Z-min of the ROI to include the whole bottom of the bin, this makes our point cloud unusable for detections.