Overlay File Format

Projection Information

The first line must contain the keyword PROJECTION followed by the type of Projection, which must be one of LatLon, Lambert or UTM.

Example:  PROJECTION: LatLon

The next line must contain the keyword ELLIPSOID followed by the ellipsoid to be used with the projection. The Ellipsoids must be one of: Clarke 1880, GRS 1967, GRS 1980, International 1909, International 1924, SGS 1985, Sphere, WGS 1960, WGS 1966, WGS 1972, WGS 1984.

Example:  ELLIPSOID: WGS 1984

After this, each projection has a required set of parameters that is different for each one. 

For the LatLon projection, the following parameter is required:

CenterLongitude: 68.7

For the Lambert projection, the following parameters are required:

NorthLatitude: 30.0
SouthLatitude: 60.0
CenterLongitude: -66.0
CenterLatitude: 45.0

For the UTM projection, the following parameter is required:

UTMZone: 19

Labeled Points

You may specify sets of labeled points in a points section which must begin with BEGIN_POINTS and end with END_POINTS. Each point will have some text associated with it. You can specify the symbol type, color and size. You can also specify the text font, color and orientation about the point.

Symbol Type

To set the symbol type, use the SHAPE keyword followed by one of the following shapes: circle, square, triangle, diamond, cross, star or none.

Example: SHAPE: circle

Symbol Color

To set the symbol color, use the SYMBOLCOLOR keyword and one of the available colors: black, blue, cyan, darkGray, gray, green, lightGray, magenta, orange, pink, red, white or yellow.

Symbol Size

To set the symbol size, use the SYMBOLSIZE keyword followed by an integer that is the size of the symbol in pixels.

Font

To set the font type, use the FONT keyword followed by one of the fonts available on your system. 

Font Style

To set the font style, use the FONTSTYLE keyword followed by plain, bold, italic or bolditalic.

Font Size

To set the font size, use the FONTSIZE keyword followed by an integer that is the font size in points (ie:10, 12, 14, etc)

Font Color

To set the font color, use the FONTCOLOR keyword followed by one of the available colors: black, blue, cyan, darkGray, gray, green, lightGray, magenta, orange, pink, red, white or yellow.

Text Orientation

The text can be oriented about the symbol in any of the eight compass directions or in the center of the point. To set the orientation, use the ORIENTATION keyword followed by one of the following directions: north, northeast, east, southeast, south, southwest, west, northwest or center.

Placing points

To place a labeled point, use a line with some text, the X coordinate and the Y coordinate separated by commas. 

Example: Office building, 64.546, 44.325

You may specify several points by placing one on each row. 

There is an example of a file with points at the end of this file.

Polygons

The polygon section must begin with the keyword BEGIN_POLYGONS and end with the keyword END_POLYGONS.

Polygons may be either closed filled polygons, closed unfilled polygons or open polygons. You can specify the outline color,  the fill color, the line thickness and the line style. As with the points, you specify these parameters and they remain in effect until you change them. You may set the attributes, specify several polygons and then change the attributes for the next set of polygons.

Polygon Type

To set the polygon type, use the TYPE keyword and one of the following types: filled, outline, line. A filled polygon will have an outline and an interior filled with a color. An outline polygon will be a closed polygon with an outline. A line will be an open polygon that does not close.

Fill Color

The fill color of a filled polygon can be set with the FILLCOLOR keyword followed by one of the available colors: black, blue, cyan, darkGray, gray, green, lightGray, magenta, orange, pink, red, white or yellow. This will only be used for polygons that are filled.

Line Color

The line color of any polygon can be set with the LINECOLOR keyword followed by one of the available colors: black, blue, cyan, darkGray, gray, green, lightGray, magenta, orange, pink, red, white or yellow.

Line Thickness

The line thickness of any polygon can be set with the LINECOLOR keyword followed by an integer that is the line thickness in pixels.

Line Style

The line style of any polygon can be set with the LINESTYLE keyword followed by one of the following styles: solid, dashed, long dashed, double dashed, dash dot or dash double dot.

Specifying a Polygon

To specify a polygon, use the NUMPOINTS keyword followed by the number of points that will be in the polygon. Then place the points, one per line, following this with X coordinate and Y coordinate separated by a comma.

Example:

NUMPOINTS:4
-68.75, 44.70
-68.80, 44.70
-68.80, 44.75
-68.75, 44.75

There is an example of a polygon file at the end of this file.

Sample overlay file with labeled points

PROJECTION:LatLon
ELLIPSOID:WGS 1984
CenterLongitude:-68.7

BEGIN_POINTS
SHAPE: circle
FONT: Arail
FONTSTYLE: Italic
FONTSIZE: 14
# This will illustrate the orientation feature.
ORIENTATION:north
north, -68.755, 44.72
SHAPE: square
SYMBOLCOLOR: red
ORIENTATION:northeast
northeast, -68.743, 44.714
SHAPE: triangle
SYMBOLCOLOR: orange
ORIENTATION:east
east, -68.735, 44.705
SHAPE: diamond
SYMBOLCOLOR: green
ORIENTATION:southeast
southeast, -68.743, 44.695
SHAPE: cross
SYMBOLCOLOR: magenta
ORIENTATION:south
south, -68.755, 44.69
SHAPE: star
SYMBOLCOLOR: pink
ORIENTATION:southwest
southwest, -68.767, 44.695
SHAPE: circle
SYMBOLCOLOR: cyan
ORIENTATION:west
west, -68.775, 44.705
SYMBOLCOLOR: gray
ORIENTATION:northwest
northwest, -68.767, 44.714
ORIENTATION:center
SHAPE:none
center, -68.755, 44.705

END_POINTS

Sample file with Polygons

PROJECTION:LatLon
ELLIPSOID:WGS 1984
CenterLongitude:-68.7

BEGIN_POLYGONS
TYPE:filled
FILLCOLOR:pink
LINETHICKNESS:2
LINESTYLE: solid
NUMPOINTS:4
-68.75, 44.70
-68.80, 44.70
-68.80, 44.75
-68.75, 44.75
TYPE:filled
FILLCOLOR:orange
LINETHICKNESS:5
LINECOLOR:magenta
NUMPOINTS:5
-68.82, 44.76
-68.80, 44.75
-68.81, 44.73
-68.83, 44.73
-68.84, 44.75
LINECOLOR:Black
TYPE:outline
NUMPOINTS:4
-68.81, 44.73
-68.83, 44.73
-68.81, 44.68
-68.83, 44.68
TYPE:line
LINECOLOR: red
LINESTYLE: dashed
NUMPOINTS:2
-68.80, 44.68
-68.70, 44.72 
END_POLYGONS