NAME¶
img2google - Create Google Earth KML overlay tiles from bathymetry Mercator img
grid
SYNOPSIS¶
img2google
-Rwest/
east/
south/
north[
r] [
imgfile ] [
-Amode[
altitude ] ] [
-C ] [
-Ffademin/fademax ] [
-Gprefix ] [
-LLODmin/LODmax ] [
-Nlayername ] [
-Tdoctitle ] [
-UURL ] [
-V ] [
-Z ]
DESCRIPTION¶
img2google reads a 1x1 minute Mercator surface relief img file and
creates a Google Earth overlay KML file and associated PNG tile for the
specified region. If no input file is given we use topo.11.1.img.
- -R
- west, east, south, and north specify the
Region of interest, and you may specify them in decimal degrees or in
[+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and
upper right map coordinates are given instead of w/e/s/n. The two
shorthands -Rg and -Rd stand for global domain (0/360 and
-180/+180 in longitude respectively, with -90/+90 in latitude).
Alternatively, specify the name of an existing grid file and the -R
settings (and grid spacing, if applicable) are copied from the grid.
OPTIONS¶
- imgfile
- An img format bathymetry/topography file such as those
created by Sandwell and Smith. If this files does not exist in the current
directory and the user has set the environment variable
$GMT_DATADIR, then img2mercgrd will try to find
imgfile in $GMT_DATADIR.
- -A
- Selects one of 5 altitude modes recognized by Google Earth
that determines the altitude (in m) of the image: G clamped to the
ground, g append altitude relative to ground, a append
absolute altitude, s append altitude relative to seafloor, and
S clamp it to the seafloor [Default].
- -C
- Turn on clipping so that only portions below sea level will
be visible in the image [no clipping].
- -F
- Sets the distance over which the geometry fades, from fully
opaque to fully transparent. These ramp values, expressed in screen
pixels, are applied at the minimum and maximum end of the LOD (visibility)
limits, respectively. [no fading (0/0)].
- -G
- Specify the prefix for the output image file (the
extensions are set automatically). Default uses the naming topoN|S
<north>E|W< west>.
- -L
- Measurement in screen pixels that represents the minimum
limit of the visibility range for a given Region Google Earth calculates
the size of the Region when projected onto screen space. Then it computes
the square root of the Region's area (if, for example, the Region is
square and the viewpoint is directly above the Region, and the Region is
not tilted, this measurement is equal to the width of the projected
Region). If this measurement falls within the limits defined by
LODmin and LODmax (and if the region is in view), the Region
is active. If this limit is not reached, the associated geometry is
considered to be too far from the user's viewpoint to be drawn.
LODmax represents the maximum limit of the visibility range for a
given Region. A value of −1, the default, indicates "active to
infinite size." [always active].
- -N
- Append the layername of the image (use quotes if strings
contain spaces) [topoN|S <north>E|W<west>].
- -T
- Append the document title (use quotes if strings contain
spaces) ["Predicted bathymetry"].
- -U
- By default, images are referenced locally relative to the
KML file. Specify an URL to prepend a server address to the image name
reference [local].
- -V
- Selects verbose mode, which will send progress reports to
stderr [Default runs "silently"].
- -Z
- Uses zip (which must be installed) to create a *.kmz file
for easy distribution; append + to delete the KML and PNG file
after zipping [No zipping].
EXAMPLES¶
To create a 10x10 degree Google Earth KML tile for the region
-R170/180/20/30 using the default
topo.11.1.img and output
naming convention, try
img2google -R170/180/20/30
To make the same tile with the previous
topo.10.1.img, run in verbose
mode, clip so only oceanic areas are visible, name the output oldimage,
specify the KML metadata directly (including setting the image altitude to 10
km), and make a single *.kmz file, try
img2google topo.10.1.img -R170/180/20/30
-AA10000
-C -Goldimage -N"My
KML title"
-T"My KML title"
-Uhttp://my.server.com/images -V -Z
DATA SETS¶
For topo.11.1.img and other Sandwell/Smith altimetry-derived Mercator grids,
visit
http://topex.ucsd.edu.
SEE ALSO¶
GMT(1),
img2grd(1) img2mercgrd(1) ps2raster(1)