====== Preferences of Cable Detection =====

This page describes only the parameters and preferences of Cable Detector. \\
Full documentation about semi-automatic detectors, see [[204:technology:3d_mapping:measurements|]].
General concepts of Detectors Preferences, see [[204:desktop:preferences:detectors|]].

**Feature Extraction** and **Feature Extraction Pro**\\
{{orbit_desktop:entrance_icon_2.png?nolink&25 |}}  [[204:desktop:workspace:main_toolbar|Main Toolbar]] > Preferences > Detectors > Cable Detection

{{  :204:desktop:preferences:preferences_cable_1930.png?nolink  |}}

===== Algorithm =====
In process of detecting a cable is modeled as sequence of line segments which should meet certain criteria.\\

**Prox dist cluster** and **Min pts cluster**\\
Parameters define how points will be clustered together: iterational process - If inside 'Prox. dist cluster' distance around existing cluster at least "Min pts cluster' amount of points is found they will be added to the cluster.

**Dist pts to cable**\\
Half of maximum diameter of a cable.\\

**Start window width**\\
The first segment is determined by clustering points starting from the point of initial measurement (let's call it a seed cluster) and inside cube of 'Start window width' size around that point and finding best fitting line segment. Cluster will be rejected and measurement stopped if cluster width is bigger than maximum diameter of a cable.\\

**Search window width**, **Search window length** and **Small window width**, **Small window length**\\
Next segment will be detected by searching for points along the line containing previously found segment in both directions. Search window defines the search volume for candidate points; small window allows to split the candidate points into small enough parts to be approximated by line segments.

**Cable noise max** and **End cable by noise**\\
Noise is defined by amount of points in a cluster  which are more than radius of the cable distance away from the best fitting segment. It's possible to stop detector if noise exceeds maximum parameter.

**End cable by height**\\
Cables are expected to have certain geometry. This check box enables stopping measurement in case if segment with positive slope has consecutive segment having negative slope.

===== Output =====

**Final line Distance points**\\
Distance between the vertexes of the final output lines.\\

**Fit catenary line**\\
Use special algorithm to get the catenary curve. If disabled detected segments will be joined together by approximated smooth line.
== Detect parallel cables==
**Parallel cable search slice** and **Radius parallel cables**\\
Size (thickness and radius) of a vertical slice perpendicular to a detected cable. Clusters of points in this slice are used as seed clusters (see above) to start new cable detection.

== Extend cable beyond poles ==
**Dist search extend cable**\\
To extend a cable beyond a pole a vertical slice perpendicular to the cable is created and seed clusters of points are found.\\

**Dist next cable line max** and **Overlap cables max**\\
Starting with the seed clusters new cable lines are detected.They will be accepted if the distance to initial cable line and overlap with it do not exceed provided maximum values.