workbench/libs/lcms2/utils/samples/itufax.c

   1 //
   2 //  Little cms
   3 //  Copyright (C) 1998-2003 Marti Maria
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining
   6 // a copy of this software and associated documentation files (the "Software"),
   7 // to deal in the Software without restriction, including without limitation
   8 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9 // and/or sell copies of the Software, and to permit persons to whom the Software
  10 // is furnished to do so, subject to the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be included in
  13 // all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
  17 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22
  23
  24 #include "lcms.h"
  25
  26 // This is a sample on how to build a profile for decoding ITU T.42/Fax JPEG
  27 // streams. The profile has an additional ability in the input direction of
  28 // gamut compress values between 85 < a < -85 and -75 < b < 125. This conforms
  29 // the default range for ITU/T.42 -- See RFC 2301, section 6.2.3 for details
  30
  31
  32 //  L*  =       [0, 100]
  33 //      a*      =       [–85, 85]
  34 //      b*      =       [–75, 125]
  35
  36
  37 // These functions does convert the encoding of ITUFAX to floating point
  38
  39 static
  40 void ITU2Lab(WORD In[3], LPcmsCIELab Lab)
  41 {
  42    Lab -> L = (double) In[0] / 655.35;
  43    Lab -> a = (double) 170.* (In[1] - 32768.) / 65535.;
  44    Lab -> b = (double) 200.* (In[2] - 24576.) / 65535.;
  45 }
  46
  47
  48 static
  49 void Lab2ITU(LPcmsCIELab Lab, WORD Out[3])
  50 {
  51         Out[0] = (WORD) floor((double) (Lab -> L / 100.)* 65535. + 0.5);
  52     Out[1] = (WORD) floor((double) (Lab -> a / 170.)* 65535. + 32768. + 0.5);
  53     Out[2] = (WORD) floor((double) (Lab -> b / 200.)* 65535. + 24576. + 0.5);
  54 }
  55
  56
  57 // These are the samplers-- They are passed as callbacks to cmsSample3DGrid()
  58 // then, cmsSample3DGrid() will sweel whole Lab gamut calling these functions
  59 // once for each node. In[] will contain the Lab PCS value to convert to ITUFAX
  60 // on InputDirection, or the ITUFAX value to convert to Lab in OutputDirection
  61 // You can change the number of sample points if desired, the algorithm will
  62 // remain same. 33 points gives good accurancy, but you can reduce to 22 or less
  63 // is space is critical
  64
  65 #define GRID_POINTS 33
  66
  67 static
  68 int InputDirection(register WORD In[], register WORD Out[], register LPVOID Cargo)
  69 {
  70     cmsCIELab Lab;
  71
  72     cmsLabEncoded2Float(&Lab, In);
  73     cmsClampLab(&Lab, 85, -85, 125, -75);    // This function does the necessary gamut remapping
  74     Lab2ITU(&Lab, Out);
  75
  76         return TRUE;
  77 }
  78
  79
  80 static
  81 int OutputDirection(register WORD In[], register WORD Out[], register LPVOID Cargo)
  82 {
  83
  84         cmsCIELab Lab;
  85
  86     ITU2Lab(In, &Lab);
  87     cmsFloat2LabEncoded(Out, &Lab);
  88
  89         return TRUE;
  90 }
  91
  92
  93 // The main entry point. Just create a profile an populate it with required tags.
  94 // note that cmsOpenProfileFromFile("itufax.icm", "w") will NOT delete the file
  95 // if already exists. This is for obvious safety reasons.
  96
  97
  98 int main(int argc, char *argv[])
  99 {
 100         LPLUT AToB0, BToA0;
 101         cmsHPROFILE hProfile;
 102
 103         fprintf(stderr, "Creating itufax.icm...");
 104
 105         unlink("itufax.icm");
 106         hProfile = cmsOpenProfileFromFile("itufax.icm", "w");
 107
 108     AToB0 = cmsAllocLUT();
 109         BToA0 = cmsAllocLUT();
 110
 111         cmsAlloc3DGrid(AToB0, GRID_POINTS, 3, 3);
 112         cmsAlloc3DGrid(BToA0, GRID_POINTS, 3, 3);
 113
 114         cmsSample3DGrid(AToB0, InputDirection, NULL, 0);
 115         cmsSample3DGrid(BToA0, OutputDirection, NULL, 0);
 116
 117     cmsAddTag(hProfile, icSigAToB0Tag, AToB0);
 118         cmsAddTag(hProfile, icSigBToA0Tag, BToA0);
 119
 120
 121         cmsSetColorSpace(hProfile, icSigLabData);
 122     cmsSetPCS(hProfile, icSigLabData);
 123     cmsSetDeviceClass(hProfile, icSigColorSpaceClass);
 124
 125         cmsAddTag(hProfile, icSigProfileDescriptionTag, "ITU T.42/Fax JPEG CIEL*a*b*");
 126     cmsAddTag(hProfile, icSigCopyrightTag,          "No Copyright, use freely.");
 127     cmsAddTag(hProfile, icSigDeviceMfgDescTag,      "Little cms");
 128     cmsAddTag(hProfile, icSigDeviceModelDescTag,    "ITU T.42/Fax JPEG CIEL*a*b*");
 129
 130         cmsCloseProfile(hProfile);
 131
 132         cmsFreeLUT(AToB0);
 133         cmsFreeLUT(BToA0);
 134
 135         fprintf(stderr, "Done.\n");
 136
 137         return 0;
 138 }