Profile Filter

The Profile Filter tool provides processing filters that you can apply to a uniform profile (not point cloud profiles), letting you process scan data to get more repeatable measurements. You can enable up to seven of the filters at once, in any order. Filters in the tool are chained together. Any Profile tool can use the resulting filtered profile as input.

(The following screenshot is from a G2 sensor.)

Profile with no filtering (top) and with averaging filter (bottom)

For a list of the filters, see Filters.

The Filter tool provides no measurements or decisions. It only outputs processed profile data.

A limited set of filters is also available on the Scan page. These filters let you process scan data without needing to add tools. This can be useful if you are using a sensor mostly as an acquisition device.

For information on adding, managing, and removing tools, as well as detailed descriptions of settings common to most tools, see Tool Configuration.

Inputs

You configure the tool's inputs in the expandable Inputs section.

To use a measurement as an anchor, it must be enabled and properly configured in the tool providing the anchor. For more information on anchoring, see Measurement Anchoring.

Inputs
Name Description
Enable Batching

When Enable Batching is checked, the tool takes an array as input and processes each profile in the array individually. There is no limit to the size of the array, other than the processing limitations of the sensor.

For more information on arrays, batching, and aggregating, see Arrays, Batching, and Aggregation.

Profile Input

The data the tool applies measurements to or processes.

Anchor X or Anchor Z

The X or Z measurement of another tool that this tool uses as a positional anchor. Positional anchors are optional.

Parameters

You configure the tool's parameters in the expandable Parameters section.

Parameters
Parameter Description

Use Region

When enabled, displays Region parameters (see below). When disabled, the tool uses all data.

Number of Regions

Region {n}

Lets you set the number of regions, and for each region, the position and dimension.

For more information on regions, see Regions.

Filter Type

The type of filter. For more information on the available filters, see Filters.

Units

The units the filter uses for the window or windows: points or distance (mm). Not available with all filters. This parameter is only displayed after enabling Filter in X or Filter in Y.

Filter in X

Filter in Y

When enabled, filters along X and Y, respectively, and displays X Window Size or Y Window Size parameters you use to set the window size, using the unit set in Units. (The gap filling and Gaussian filters only let you filter along the X axis.)

The filter window sizes are specified in millimeters (and additionally, in the tools, in data points). To calculate the number of data points that a window covers when the units are millimeters, use the following calculation:

  • User-specified window size divided by the X spacing interval (that is, the number of millimeters per point) on the Spacing tab in the Sensor panel. (For more information on spacing intervals, see Uniform Spacing.)
  • With the exception of the gap filling filter, round the result of the division to the nearest integer value. With the gap filling filter, filling is performed within the provided window size.

For example, if you set the size of the filter's window to a value between 1.5 mm and 2.49 mm (inclusively), and the X spacing interval is set to 1 mm, the filter covers 2 data points. A filter window size from 2.5 mm to 3.49 mm results in a filter covering 3 data points.

Sigma

The Gaussian curve’s sigma value. (Only displayed with the Gaussian filter and when Filter in X is enabled.)

Percentile Type

Displayed when Filter Type is Percentile. (Be sure to set the High Percentile and Low Percentile as required.) One of the following:

Point Count: Removes points based on the count of valid points in the profile.

Point Height Range: Removes points based on the height range of valid points in the profile.

High Percentile

Low Percentile

The range for used when you set Filter Type to Percentile. You must also set Percentile Type.

The following filters are available in the Profile Filter tool.

Filters
Name Description

Gap Filling

Fills in missing data using information from the nearest neighbor data points, for example, when data is missing due to occlusions. Gap filling also fills gaps where no data is detected, which can be due to low surface reflectivity, for example dark or specular surface areas, or to actual gaps in the surface. The values in Filter in X and Filter in Y represent the maximum gaps the sensor will fill. Wider gaps are not filled.

Gap filling works by filling in missing data points using either the lowest values from the nearest neighbors or linear interpolation between neighboring values (depending on the Z difference between neighboring values), in the specified window. The sensor can fill gaps along both the X axis and the Y axis.

In Profile mode, gap filling is limited to the X axis.

Median

Substitutes the value of a data point with the median calculated within the window or windows set in X Window Size or Y Window Size around the data point. If the number of valid (non-null) data points in the window is even, the median value is simply the value in the center of the sorted list of values. If the number of valid points is odd, the average of the two values in the center is used instead.

Missing data points will not be filled with the median value calculated from data points in the neighborhood.

With an odd window size, the output is at the center of the window. With an even window size, the output is 0.5 pixels to the right of the center (that is, using window / 2-1 values from the left, and window / 2 from the right.

Averaging

Substitutes a data point value with the mean value of that data point and its nearest neighbors within the window or windows set in X Window Size or Y Window SizeX smoothing works by calculating a moving average across samples along the X axis. Y smoothing works by calculating a moving average along the X axis.

If both X and Y smoothing are enabled, the data is smoothed along X axis first, then along the Y axis.

Missing data points will not be filled with the mean value calculated from data points in the neighborhood.

Decimation

Decimation reduces the number of data points along the X or Y axis by choosing data points at the end of a specified window around the data point. For example, by setting X Window Size to 0.2, only points every 0.2 millimeters will be used. The filter generates points starting from the leftmost edge of the scan data, stepping in equal steps away from that side.

Gaussian

A Gaussian filter applied over the specified kernel using the provided sigma. Enable Filter in X and set the Sigma parameter.

Percentile

Filters points based on Percentile Type, as well as High Percentile and Low Percentile.

The filters described here that are available in the Filter panel topic use the same algorithms.

Outputs

The tool provides the following output.

Data
Type Description
Uniform Profile

The filtered uniform profile.