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  -R  170/180/20/30  using  the  default
       topo.11.1.img and output naming convention, try

       img2google -R 170/180/20/30

       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  -R  170/180/20/30  -AA10000 -C -Goldimage -N"My KML title" -T"My KML title" -U
       http://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)