Insert Paint Line

Semi-automatic tracing of linear intensity features particularly suited for road paint lines in dense LiDAR and point cloud data. The user roughly identifies a single point on the feature and the algorithm traces it in both directions until termination/failure. The user is able to specify requirements for line continuity, which allow interpolation over breaks in the line due to obstruction, worn paint, or intentional voids (as in dashed lines). The result can be interactively navigated for quality control and possible editing.

Insert Paint Line is designed to work with LiDAR and point cloud data which must include intensity attribute data for each point. This application may be started from a Function Key.

When Insert Paint Line starts, an initial point or points along the paint line needs to be digitized. This initial data provides seed information so the application can follow the paint line and place a 3D line.

	Button	Description
1	Initial point	Identifies one or points along a paint line to provide initial data to start the paint line insertion.
2
3	Review line	Review an existing line
4	Extend/hack	Extend or hack an existing line
5	Join lines	Joins two existing lines using a user defined join point
6
7	Enter params	Enter/edit Insert Paint Line parameters (see Insert Paint Line Parameters)
8	Del last line	Deletes the last saved line
9	Del line	Deletes a line by identifying an existing line
*
0
#	End	Ends application

	Button	Description
1
2	Next point	Moves cursor to the next line point
3	Prev point	Moves cursor to the previous line point
4	First point	Moves cursor to the first point on the line
5	Last point	Moves cursor to the last point on the line
6
7
8
9
*
0
#	End	Ends review and returns to the main menu

The cursor may be placed near an existing line and the closest line will be extended to or hacked at the point digitized (the hack point). If the line is to be extended the endpoint on the line will be extended along the azimuth of the last line segment. If the line is to be hacked the shortest side of the line will be hacked at a 90 degree offset from the hack point. After the hack point has been digitized and the line extended or hacked, the result may will be displayed and may be accepted or rejected before re-saving the line.

	Button	Description
1	Dig hack pt	Digitizes the hack point when extending or hacking a line
2
3
4
5
6
7
8
9
*
0
#	End	Ends Extend/hack and returns to the main menu

Two existing lines may be joined by placing the cursor near both lines and digitizing a point (the join point). The join point will be the common point between the two lines. Lines will be extended or hacked to the join point. After the join point has been digitized and the lines joined, the result may will be displayed and may be accepted or rejected before re-saving the lines.

	Button	Description
1	Dig join pt	Digitizes the join point when joining two lines
2
3
4
5
6
7
8
9
*
0
#	End	Ends Join Lines and returns to the main menu

Deletes an existing line. When a line is identified to be deleted it may be accepted or rejected before deletion.

	Button	Description
1	Id line	Identifies the line to delete
2
3
4
5
6
7
8
9
*
0
#	End	Ends Delete Line and returns to the main menu

The Insert Paint Line parameters may be defined by pressing button 7 from the Main menu.

The user may select to start a paint line trace with either one or two input points. One point starts are usually successful, but are somewhat more sensitive to other parameters. If a data set is noisy, sparse and/or has lines that vary widely in width it may simply be easier use a single wide 'Max line width' and do two point starts. (default=1)

The typical distance between points on the line. Rapid curvature, noise, lines ending etc. may cause the point density to increase. (ground, default=8)

The maximum acceptable void in the the line's signal. Voids are caused by vegetation, debris, spare data, dashed lines, etc. As long as these voids are less than 'Max jump distance' across, the algorithm will try to bridge across them. (ground, default=20)

The maximum acceptable width (measured edge to edge) of the paint line. (ground, default=1.2)

The maximum allowed change in direction for a new line segment in degrees. The smaller the curve limit the more points will be included while the line changes direction. (degrees, default=5)

This parameter limits the number of points that are used in processing each line segment. This prevents lag when processing very dense data. (default=300)

Search radius and endpoint extend distance when searching for lines to join or extend. (ground, default=10)

The following key-ins may be used to change run-time parameters. They may be keyed in, placed in macros or more commonly placed in the Local Args field in a Function Key.

Key-in	Description	Range
Lay=	Layer number	1-32001
Mod=	Mode	1=Line 2=Spline
Grp=	Graphic pointer	1-1000
Wid=	Line width	0-255
Pen=	Pen number	1-256
Con=	Construction flag	0-1
Ngr=	Non graphic pointer	32-bit
Lnk=	Link number	32-bit
Fc=	Feature code	15 char

NumPts=	Number user input points	1 or 2 (default=1)
PntSpa=	Point spacing	ground (default=1)
MaxJum=	Maximum jump distance	ground (default=20)
MaxWid=	Maximum line width	ground (default=1.2)
MaxAng=	Line curve limit	degrees (default=5)
MaxPts=	Maximum points	number of points (default=300)
LinSea=	Line search radius	ground (default=10)