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   ssaattuurraa--
       ttiioonn__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 satu-
       ration components and produces  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 settings 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 compo-
	      nent in the data.

       ggrreeeenn__oouuttppuutt==_n_a_m_e
	      Output raster map layer representing the _g_r_e_e_n com-
	      ponent in the data.

       bblluuee__oouuttppuutt==_n_a_m_e
	      Output raster map layer representing the _b_l_u_e  com-
	      ponent 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 repro-
       duced exactly after transformation in both directions  and
       that  99% will be within plus or minus 1.  A few cell val-
       ues 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  Univer-
       sity


       with  acknowledgements  to  Ali Vali, Univ. of Texas Space
       Research Center, 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)
