photo.rectify(1)	      Grass User's Manual	      photo.rectify(1)



_T_h_i_s  _i_s _n_o_t _a _c_o_m_m_a_n_d _i_n _i_t_s_e_l_f_, _b_u_t _a_n _o_p_t_i_o_n _o_f _t_h_e _c_o_m_m_a_n_d _i_._o_r_t_h_o_._p_h_o_t_o .

NNAAMMEE
       _p_h_o_t_o_._r_e_c_t_i_f_y - An imagery function that rectifies an image by  comput-
       ing a coordinate transformation for each cell in the image using param-
       eters computed by the GRASS programs _p_h_o_t_o_._2_i_m_a_g_e and _p_h_o_t_o_._2_t_a_r_g_e_t.
       _(_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
       Selected from _i_._o_r_t_h_o_._p_h_o_t_o


DDEESSCCRRIIPPTTIIOONN
       _p_h_o_t_o_._r_e_c_t_i_f_y rectifies an image by using the image to photo coordinate
       transformation  matrix  created	by  photo.2image and the rectification
       parameters created by photo.2target. Rectification is  the  process  by
       which  the  geometry  of  an image is made planimetric.	This is accom-
       plished by mapping an image from one coordinate system to  another.  In
       photo.rectify the parameters computed by photo.2image and photo.2target
       are used in equations to convert x,y image coordinates to standard  map
       coordinates for each pixel in the image.  The result is an image with a
       standard map coordinate system, compensated for relief distortions  and
       photographic  tilt.  Upon completion of the program the rectified image
       is deposited in a previously targeted GRASS LOCATION.

	You are asked to select the file(s) within the	imagery  group	to  be
       rectified:

	Please select the file(s) to rectify by naming an output file


       gs13.1	 in    PERMANENT      gs13.orect...    gs14.1	in   PERMANENT
       .............  (enter list by any name to get a list of	existing  cell
       files) AFTER COMPLETING ALL ANSWERS, HIT  TO CONTINUE (OR  TO CANCEL)





       More than one file may be rectified at a time.  Each file should have a
       unique output file name.


       The next prompt asks you to select one of two windows:



	     Please select one of the following options
	     1.   Use the current window in the target location
	     2.   Determine the smallest window which covers the image
	     >


	_p_h_o_t_o_._r_e_c_t_i_f_y will only rectify that portion of the image that	occurs
       within  the  chosen window.  Only that portion will be relocated in the
       target database. It is therefore important to check the current	window
       in the target LOCATION if choice number one is selected.


       _p_h_o_t_o_._r_e_c_t_i_f_y will run in the background and notify you by mail when it
       is finished. The process may take an hour or more depending on the size
       of  the	image,	the  number  files, and the size and resolution of the
       selected window.

	The rectified image will be located in the target  LOCATION  when  the
       program	is  completed. The original unrectified files are not modified
       or removed.

SSEEEE AALLSSOO
       _i_._o_r_t_h_o_._p_h_o_t_o

       _p_h_o_t_o_._c_a_m_e_r_a

       _p_h_o_t_o_._2_i_m_a_g_e

       _p_h_o_t_o_._2_t_a_r_g_e_t

       _p_h_o_t_o_._i_n_i_t


AAUUTTHHOORR
       Mike Baba,  DBA Systems, Inc.

       Updated rectification and elevation map to FP 1/2002 Markus Neteler

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_2_/_2_8 _2_3_:_4_6_:_5_7 _$



GRASS 5.0						      photo.rectify(1)
