From octave-sources-request at bevo dot che dot wisc dot edu  Fri Jan  5 19:25:04 2001
Subject: Colour management using ICC profiles
From: adler at freenet dot carleton dot ca
To: octave-sources at bevo dot che dot wisc dot edu
Date: Fri, 5 Jan 2001 20:31:34 -0500 (EST)

The following code implements image colour management
using ICC profiles for octave.

It depends on the lcms library; the build instructions
are in the header.

For more information of ICC colour management,
take a look at the references in the header.

_______________________________________
Andy Adler,                adler at ncf dot ca

/*
 * Octave dl code to do image conversions using icc colour profiles.
 *
 * (c) 2001 Andy Adler
 *  $Id: icc_cnvt.cc,v 1.1 2001/01/05 17:45:22 aadler Exp aadler $
 *
 * Note, this file depends on the littlecms library,
 * available at www.littlecms.com.
 *
 * Build Instructions:
 *
 * 1. Download the unix version of lcms from
 *     http://www.littlecms.com/download.htm
 *
 * 2. Build the lcms using
 *     ./configure
 *     make
 *
 * 3. Set:  LCMS=<lcms base directory>/source
 *
 * 4. Make this file:
 *     mkoctfile icc_cnvt.cc -I$LCMS -L$LCMS -llcms
 *
 * Note:
 *
 * For more information about icc colour management, refer to 
 * www.color.org
 * www.coloraid.de
 * www.freecolormanagement.com
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <octave/oct.h>
#include <octave/oct-map.h>
#include "lcms.h"

DEFUN_DLD (icc_cnvt, args, ,
  "img_out = icc_cnvt (img_in, prof1, prof2, intent)\n\
\n\
img_out - output image with red, green, blue components\n\
       ( img_out.r, img_out.g, img_out.b )\n\
img_in - input image with red, green, blue components\n\
       ( img_in.r, img_in.g, img_in.b )\n\
\n\
       Note: images components must be (0-255)\n\
\n\
prof1  - input icc    colour profile filename (AtoB)\n\
prof2  - input output colour profile filename (BtoA)\n\
intent - rendering intent: one of\n\
           INTENT_PERCEPTUAL   - default\n\
           INTENT_RELATIVE_COLORIMETRIC\n\
           INTENT_SATURATION\n\
           INTENT_ABSOLUTE_COLORIMETRIC\n\
")
{
  // The list of values to return.  See the declaration in oct-obj.h

  octave_value_list retval;
  int nargin= args.length();

  if ( nargin < 3 || !args(0).is_map() ||
                     !args(1).is_string() ||
                     !args(2).is_string()  ) {
     usage( "icc_cnvt" );
     return retval;
  }

  int Intent= INTENT_PERCEPTUAL;

  if (nargin >=4) {
     string intent= args(3).string_value();
     if (intent=="INTENT_PERCEPTUAL")
        Intent= INTENT_PERCEPTUAL;
     else
     if (intent=="INTENT_RELATIVE_COLORIMETRIC")
        Intent= INTENT_RELATIVE_COLORIMETRIC;
     else
     if (intent=="INTENT_SATURATION")
        Intent= INTENT_SATURATION;
     else
     if (intent=="INTENT_ABSOLUTE_COLORIMETRIC")
        Intent= INTENT_ABSOLUTE_COLORIMETRIC;
  printf("%s->%d\n", intent.c_str(), Intent);
  }

  Octave_map c_in= args(0).map_value();
  const Matrix r0= c_in["r"].matrix_value();
  const Matrix g0= c_in["g"].matrix_value();
  const Matrix b0= c_in["b"].matrix_value();

  int n= r0.rows();
  int m= r0.cols();

  if ( m != g0.cols() || m != b0.cols() ||
       n != g0.rows() || n != g0.rows() ) {
     error("R,G,B, components must be same size");
     return retval;
  }

  // Output Matrices
  Matrix r1( n,m );
  Matrix g1( n,m );
  Matrix b1( n,m );

  //
  // Colour processing starts here
  //
  cmsHPROFILE hInProfile  =
         cmsOpenProfileFromFile(args(1).string_value().c_str(), "r");
  cmsHPROFILE hOutProfile =
         cmsOpenProfileFromFile(args(2).string_value().c_str(), "r");

  cmsHTRANSFORM hTransform =
         cmsCreateTransform(hInProfile,
                            TYPE_RGB_8,
                            hOutProfile,
                            TYPE_RGB_8,
                            Intent, 0);

  unsigned char inbuf [3*m];
  unsigned char outbuf[3*m];

  for (int i=0; i < n; i++)
  {
    for( int j=0,p=0; j < m; j++ ) {
      inbuf[ p++ ] = (unsigned int) r0(i,j);
      inbuf[ p++ ] = (unsigned int) g0(i,j);
      inbuf[ p++ ] = (unsigned int) b0(i,j);
    }

    cmsDoTransform(hTransform, inbuf, outbuf, m );

    for( int j=0,p=0; j < m; j++ ) {
      r1(i,j) = outbuf[ p++ ];
      g1(i,j) = outbuf[ p++ ];
      b1(i,j) = outbuf[ p++ ];
    }
  }

  cmsDeleteTransform(hTransform);
  cmsCloseProfile(hInProfile);
  cmsCloseProfile(hOutProfile);

  Octave_map c_out;
  c_out["r"]= r1;
  c_out["g"]= g1;
  c_out["b"]= b1;

  retval(0)= c_out;
  return retval;

}




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