i.his.rgb(1)		      Grass User's Manual		  i.his.rgb(1)



NNAAMMEE
       ii..hhiiss..rrggbb   -  Hue-intensity-saturation	(his)  to red-green-blue (rgb)
       raster map color transformation function.
       _(_G_R_A_S_S _I_m_a_g_e _P_r_o_c_e_s_s_i_n_g _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       ii..hhiiss..rrggbb
       ii..hhiiss..rrggbb hheellpp
       ii..hhiiss..rrggbb  hhuuee__iinnppuutt==_n_a_m_e  iinntteennssiittyy__iinnppuutt==_n_a_m_e	 ssaattuurraattiioonn__iinnppuutt==_n_a_m_e
       rreedd__oouuttppuutt==_n_a_m_e ggrreeeenn__oouuttppuutt==_n_a_m_e bblluuee__oouuttppuutt==_n_a_m_e

DDEESSCCRRIIPPTTIIOONN
       _i_._h_i_s_._r_g_b  is  an  image  processing program that processes three input
       raster map layers as hue, intensity and saturation components and  pro-
       duces  three  output  raster map layers representing the red, green and
       blue components of this data.  The output raster map layers are created
       by  a  standard	hue-intensity-saturation (his) to red-green-blue (rgb)
       color transformation.  Each output raster map layer is given  a	linear
       gray  scale  color  table.  The current geographic region and mask set-
       tings are respected.

OOPPTTIIOONNSS
   PPaarraammeetteerrss::
       hhuuee__iinnppuutt==_n_a_m_e
	      Name of input raster map layer representing _h_u_e.

       iinntteennssiittyy__iinnppuutt==_n_a_m_e
	      Name of input raster map layer representing _i_n_t_e_n_s_i_t_y.

       ssaattuurraattiioonn__iinnppuutt==_n_a_m_e
	      Name of input raster map layer representing _s_a_t_u_r_a_t_i_o_n.

       rreedd__oouuttppuutt==_n_a_m_e
	      Output raster map layer representing the _r_e_d  component  in  the
	      data.

       ggrreeeenn__oouuttppuutt==_n_a_m_e
	      Output  raster map layer representing the _g_r_e_e_n component in the
	      data.

       bblluuee__oouuttppuutt==_n_a_m_e
	      Output raster map layer representing the _b_l_u_e component  in  the
	      data.


NNOOTTEESS
       It  is  not  possible  to  process  three bands with _i_._h_i_s_._r_g_b and then
       exactly recover the original bands with _i_._r_g_b_._h_i_s.  This is due to loss
       of  precision because of integer computations and rounding.  Tests have
       shown that more than 70% of the original cell values will be reproduced
       exactly	after  transformation  in both directions and that 99% will be
       within plus or minus 1.	A few cell  values  may  differ  significantly
       from their original values.

SSEEEE AALLSSOO
       _h_s_v_._r_g_b_._s_h

       _i_._c_o_l_o_r_s

       _i_._r_g_b_._h_i_s

       _r_._c_o_l_o_r_s

       _r_g_b_._h_s_v_._s_h

AAUUTTHHOORR
       David Satnik, GIS Laboratory, Central Washington University


       with  acknowledgements  to Ali Vali, Univ. of Texas Space Research Cen-
       ter, for the core routine.

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_3 _$



GRASS 5.0							  i.his.rgb(1)
