Use the Extract Line Features command to create linestrings from overhead utility lines or curb and gutter features displayed in a point cloud. Intuitive, interactive 3D controls make it easy to define scan point search parameters. And, if TBC encounters a problem during the extraction process due to line feature irregularities or sparse scan points, you are provided a menu of clear options for determining how best to proceed. Before saving the linestrings, you can use the post-extraction QA/QC tools to verify and make changes to any of them as as necessary (for example, ignore or mark the line, or apply smoothing options).

Following are the basic steps for this workflow. For more detailed instructions, see Extract Line Features from a Point Cloud.

Steps:

Commands:

1.

Optionally, in the 3D View or Plan View, use the View Filter Manager or the Keep In/Keep Out commands to select to display the scan points from which you want to extract line features. Otherwise, all scan points will be displayed.

ViewFilterManager

Keep In

Keep Out

2.

Display the Extract Line Features command pane and select the type of object for which you want to extract line features.

Then see the appropriate next step below.

Extract Line Feature

3.

To extract overhead utility lines:

Optionally, specify properties for the resulting linestrings.

1. Select the overhead line(s) you want to extract.
2. Select the starting and ending points for the overhead lines you want to extract (for example, where they intersect a pole).
3. The extraction of any selected overhead line will end at the opposing vertical planes defined by these two points.
4. Optionally, change the search-box length and/or width to ensure that your extracted line will be based on the appropriate available scan points.
5. Click the Extract button.
6. If the extraction process stops before completion, either make changes to the search box length/width, specify that the extraction line continue on its current trajectory path, or manually select the next scan point to use for the continuation of the extraction line. Then click the Extract button to continue. Repeat as necessary.
7. When extraction is complete, optionally use the Post QA/QC tab to select extracted lines you want to remove or mark and/or to smooth lines.
8. Click the Add (Extract tab) or Add All (Post QA/QC tab) button to save the extracted linestring.

Extract Line Feature > Overhead lines option

4.

To extract curb and gutter lines:

Note: The curb and gutter extraction process results in the creation of four linestrings, each based on the nodes that define the cross-section profile view of the feature:
- Edge of pavement
- Gutter
- Top of curve
- Back of curb

1. Optionally, specify properties for the resulting linestrings.
2. Select a point on either side of the curb and gutter feature whose lines you want to extract, resulting in a perpendicular line that is used to define a vertical cutting view plane
3. Use the Cutting Plane View to select the location of each of the nodes that will be used to extract the four curb and gutter linestrings, resulting in a curb and gutter profile template.
4. Enter or select a search interval that specifies the length of each segment to be searched and extracted at a time.
5. Enter or select a "minimum confidence" value. The higher the minimum confidence value, the more precise the extraction, but the higher the likelihood of the auto extraction process stopping, requiring your input to help it continue. The lower the value, the less precise the extraction, but the lower the likelihood of the auto extraction process stopping.
6. Click the Extract button.
7. If the extraction process stops before completion, do any of the following:
   - Change the search interval.
   - Change the confidence level.
   - Edit the template nodes.
   - Apply an "auto template"
   - Select the next node point
   - Select scan points.
   Then click the Extract button to continue. Repeat as necessary.
8. When extraction is complete, optionally use the Post QA/QC tab to select extracted lines you want to remove or mark and/or to smooth lines.
9. Click the Add (Extract tab) or Add All (Post QA/QC tab) button to save the extracted linestring.

Extract Line Feature > Curb and gutter option

5.

To extract lane line markings:

Select either of the following options:

• Semi-automated enables you to manually select the lane lines to be automatically extracted from a point cloud.
• Automatic (Mobile Mapping) enables you to automatically extract linestrings from pavement lane lines in images captured with a Trimble Mobile Mapping system that includes a 360-degree camera and laser scanner.

If you selected Semi-automated:

1. Optionally, click the Line Settings drop-down group box and enter properties for the extracted linestrings.
2. Select the type of lane line marking you want to extract: solid single, solid double, or dashed.
3. Select a point on the lane line marking. If dashed, select points in two adjacent dashes.
4. Optionally, use the Advanced Settings to:
   - Change the point cloud intensity.
   - Change the search interval.
   - Select to create line node points.
5. Click the Extract button.
6. If extraction completes in one direction, click Switch Direction and Extract to begin extraction in the opposite direction.
7. If the extraction process stops before completion, use the Advanced Settings and Manual Selection controls to do any of the following:
   - Change the search interval.
   - Manually select the next node point
   Then click the Extract button to continue. Repeat as necessary.

Extract Line Feature > Lane Line Markings option

If you selected Automatic (Mobile Mapping):

1. If your project does not already include a pre-classified Ground point cloud region, create one now (see Extract Classified Point Cloud Regions for instructions).
2. Optionally, click the Line Settings drop-down group box and enter properties for the extracted linestrings.
3. In the Data Extraction group box, select the mobile mapping run to use and optionally select to extract from a shorter section of the entire run.
4. In the Settings drop-down list, select any or all of extraction options:
   - No Refinement does not refine the extracted linestring and has a faster processing time.
   - Refine automatically applies rectification to the Mobile Mapping images and centers the extracted linestring on the lane line for a more refined, precise linestring.
   - Refine & Classify automatically identifies the line type feature attribute for each extracted linestring (for example, solid, double solid, or dashed) and display it in the point's Properties pane.
   - Create line node points automatically creates a point at each node in the extracted linestrings.
5. Click the Extract button. different options are available, depending on which Refinement Setting you selected. The options include:
   - Extract
   - Refine
   - Refine & Classify
   - Extract & Refine
   - Extract, Refine, & Classify
6. After extraction is complete, optionally expand the Filtering drop-down box and make changes as necessary:
   - Use the Limit extraction by trajectory slider control (or enter a distance value) to narrow or widen the area on either side of the selected run trajectory from which lane lines will be extracted.
   - Use the Remove short lane lines slider control (or enter a distance value) to specify the minimum length a lane line must be to be included in the extraction.
7. Do either of the following:
   - If you are certain you do not have to make changes on the Post QA/QC tab, click the Create Lines button to save the extracted linestrings in the project.
   - If you want to view or make changes on the Post QA/QC tab, select it, use the arrows to select an extracted linestring and click the appropriate option. If you did not already click the Create Lines button on the Extract tab, click the Add All button on the Post QA/QC tab to complete the extraction process by saving the extracted linestrings in the project.
8. Optionally, edit any of the newly created linestrings as necessary. See Edit a Linestring's Horizontal Segments for instructions.

Edit Linestring