<para>
   The bitmap (BMP) should be 24x24 (or smaller) and can be in
   RGB-colors (24- and 32-bit) or 8-bit indexed color format.
</para>
<para>
  If you're starting from images in another format, you may need to
  use another tool like Gimp or ImageMagick's convert to get the image
  into one of the above formats to avoid errors about "Unsupported color
  depth".
</para>
<para>
  Not all devices can support all color depths.   GPSBabel (and its
  developers) have no way of knowing what is supported on any given model
  so some experimentation may be necessary on your part.   It was reported
  that a Nuvi 3790, for example, will read the POIs only if they use 8BPP.
</para>
<para>
   A color value of 0xFF00FF (blue=255, green=0, red=255),
   also called "Magenta", can be used for transparent areas.
</para>
<para>
  <userinput>
    gpsbabel -i gpx -f "My Points.gpx" -o garmin_gpi,bitmap="tux.bmp" -F "My Points.gpi"
  </userinput>
</para>
