Noise Filter

The purpose of Noise Filter is to clean up a noisy point cloud.

Removal

The Signal-to-Noise-Ratio (SNR) filter removes points where the SNR of the projected pattern signal is below the specified limit (see Detectable Light Intensity in a Camera Capture). Points with low SNR values will be noisier (e.g. due to ambient light), and the SNR filter can, therefore, be used to preserve only the points that are deemed acceptable.

In some inspection cases, it may be desired to only preserve points with high confidence. In bin-picking scenarios, however, noisier points are typically regarded as better than no points at all. This is because, ultimately, the matching algorithm will decide whether or not the match it found is satisfactory or not.

Parameter	Value	Condition
Enabled	no	If you want to keep all points regardless of their SNR values (rarely)
	yes	If you want to control the quality of the point cloud by filtering out the points with low SNR values (usually)
Threshold	1	If you want to maximize the surface coverage but still filter out some points with low confidence, e.g., for Parcel Picking
	2-6	If you want to keep only decent quality points, for most applications, e.g., Manufacturing (Bin Picking) and E-commerce (Piece Picking). Use lower threshold values (2-3) to get points in the following scenes: dark parts, strong ambient light, and large distance.
	7+	If you want to keep only points with high confidence, e.g., Quality Inspection

Hint

SNR threshold value of 3 yields a good tradeoff between discarded points and noise.

Note

Noise Removal (SNR) filter adds close to no additional processing time.

For more information about the SNR value see SNR Value.

Repair

This filter repairs the regions of missing data due to noisy points.

Value	Condition
Enabled::no	If you require all points in your point cloud to be of high confidence.
Enabled::yes	If you want to maximize the surface coverage.

Note

Noise Repair adds additional processing time. Enabling Noise Repair and Noise Suppression adds the same processing time as enabling only one of them.

Suppression

This filter reduces noise and outliers in the point cloud.

Value	Condition
Enabled::no	If you need to distinguish very fine details and thus need to avoid any smoothing effects.
Enabled::yes	If you want to reduce noise and outliers in the point cloud or reduce ripple effects caused by interreflections.

Note

Noise Suppression adds additional processing time. Enabling Noise Suppression and Noise Repair adds the same processing time as enabling only one of them.

Version History

SDK	Changes
2.10.0	Suppression and Repair filters are added.
2.0.0	SNR filter API is added, replacing the old Contrast filter.