d.rgb(1)		      Grass User's Manual		      d.rgb(1)



NNAAMMEE
       dd..rrggbb  - Displays three user-specified raster map layers as red, green,
       and blue overlays in the active graphics frame.
       _(_G_R_A_S_S _D_i_s_p_l_a_y _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       dd..rrggbb
       dd..rrggbb hheellpp
       dd..rrggbb [--oo] rreedd==_n_a_m_e ggrreeeenn==_n_a_m_e bblluuee==_n_a_m_e

DDEESSCCRRIIPPTTIIOONN
       _R_G_B stands for red, green, and blue.  This  program  visually  combines
       three raster map layers to form a color image. For each layer, the cor-
       responding component from the layer's color table is used (e.g. for the
       red  layer, the red component is used, and so on). In general, the lay-
       ers should use a grey-scale color table.

OOPPTTIIOONNSS
   FFllaaggss::
       --oo     Overlay the resulting raster map layer onto whatever is  already
	      displayed in the active graphics frame. Any no-data areas in any
	      of the named raster maps will seem transparent, and  reveal  the
	      underlying  image previously displayed in the graphics frame. If
	      the --oo flag is set, only cells containing non-null  values  will
	      be  displayed  from  the	_o_v_e_r_l_a_i_d  raster  map. All other areas
	      (i.e., the portions of the overlaid map that contain  null  val-
	      ues) will leave the underlying display untouched.


   PPaarraammeetteerrss::
       rreedd==_n_a_m_e
	      Name of raster map layer to be used for RED component.

       ggrreeeenn==_n_a_m_e
	      Name of raster map layer to be used for GREEN component.

       bblluuee==_n_a_m_e
	      Name of raster map layer to be used for BLUE component.


NNOOTTEESS
       This is a new version of dd..rrggbb, which uses sends the data to the graph-
       ics monitor in true-color RGB format.  Unlike the previous version,  it
       does  not attempt to quantize the combined image into a fixed number of
       colors.	Nor does it have an option to generate a composite layer.  The
       image  and  raster map layers will not display properly if the graphics
       device does not have a reasonable sampling of the RGB color-space.


       If color quality of satellite image color composites  seems  to	appear
       poor,  consider	to  run rr..ccoolloorrss (greq.eq color table) on the selected
       satellite channels.


       To write out the color composite to a R/G/B raster maps, use  _i_._c_o_m_p_o_s_-
       _i_t_e (single composite map).

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       _d_._c_o_l_o_r_m_o_d_e

       _d_._c_o_l_o_r_s

       _d_._c_o_l_o_r_t_a_b_l_e

       _d_._h_i_s

       _h_s_v_._r_g_b_._s_h

       _r_._m_a_p_c_a_l_c

       _r_g_b_._h_s_v_._s_h

       _i_._c_o_m_p_o_s_i_t_e

       _r_._c_o_l_o_r_s

       _r_._c_o_m_p_o_s_i_t_e

AAUUTTHHOORR
       Glynn Clements

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GRASS 5.0							      d.rgb(1)
