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  corresponding  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 layers
       should use a grey-scale color table.

OOPPTTIIOONNSS
   FFllaaggss::
       --oo     Overlay the resulting raster map layer  onto  what-
	      ever  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 underly-
	      ing 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  values)  will
	      leave the underlying display untouched.


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

       ggrreeeenn==_n_a_m_e
	      Name of raster map layer to be used for GREEN  com-
	      ponent.

       bblluuee==_n_a_m_e
	      Name of raster map layer to be used for BLUE compo-
	      nent.


NNOOTTEESS
       This is a new version of dd..rrggbb, which uses sends the  data
       to  the graphics 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).

SSEEEE AALLSSOO
       _b_l_e_n_d_._s_h

       _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

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_4_/_1_2 _0_1_:_4_4_:_0_9 _$



GRASS 5.0						 d.rgb(1)
