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)