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//
// Little cms
// Copyright (C) 1998-2003 Marti Maria
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#include "lcms.h"
// This is a sample on how to build a profile for decoding ITU T.42/Fax JPEG
// streams. The profile has an additional ability in the input direction of
// gamut compress values between 85 < a < -85 and -75 < b < 125. This conforms
// the default range for ITU/T.42 -- See RFC 2301, section 6.2.3 for details
// L* = [0, 100]
// a* = [85, 85]
// b* = [75, 125]
// These functions does convert the encoding of ITUFAX to floating point
static
void ITU2Lab(WORD In[3], LPcmsCIELab Lab)
{
Lab -> L = (double) In[0] / 655.35;
Lab -> a = (double) 170.* (In[1] - 32768.) / 65535.;
Lab -> b = (double) 200.* (In[2] - 24576.) / 65535.;
}
static
void Lab2ITU(LPcmsCIELab Lab, WORD Out[3])
{
Out[0] = (WORD) floor((double) (Lab -> L / 100.)* 65535. + 0.5);
Out[1] = (WORD) floor((double) (Lab -> a / 170.)* 65535. + 32768. + 0.5);
Out[2] = (WORD) floor((double) (Lab -> b / 200.)* 65535. + 24576. + 0.5);
}
// These are the samplers-- They are passed as callbacks to cmsSample3DGrid()
// then, cmsSample3DGrid() will sweel whole Lab gamut calling these functions
// once for each node. In[] will contain the Lab PCS value to convert to ITUFAX
// on InputDirection, or the ITUFAX value to convert to Lab in OutputDirection
// You can change the number of sample points if desired, the algorithm will
// remain same. 33 points gives good accurancy, but you can reduce to 22 or less
// is space is critical
#define GRID_POINTS 33
static
int InputDirection(register WORD In[], register WORD Out[], register LPVOID Cargo)
{
cmsCIELab Lab;
cmsLabEncoded2Float(&Lab, In);
cmsClampLab(&Lab, 85, -85, 125, -75); // This function does the necessary gamut remapping
Lab2ITU(&Lab, Out);
return TRUE;
}
static
int OutputDirection(register WORD In[], register WORD Out[], register LPVOID Cargo)
{
cmsCIELab Lab;
ITU2Lab(In, &Lab);
cmsFloat2LabEncoded(Out, &Lab);
return TRUE;
}
// The main entry point. Just create a profile an populate it with required tags.
// note that cmsOpenProfileFromFile("itufax.icm", "w") will NOT delete the file
// if already exists. This is for obvious safety reasons.
int main(int argc, char *argv[])
{
LPLUT AToB0, BToA0;
cmsHPROFILE hProfile;
fprintf(stderr, "Creating itufax.icm...");
unlink("itufax.icm");
hProfile = cmsOpenProfileFromFile("itufax.icm", "w");
AToB0 = cmsAllocLUT();
BToA0 = cmsAllocLUT();
cmsAlloc3DGrid(AToB0, GRID_POINTS, 3, 3);
cmsAlloc3DGrid(BToA0, GRID_POINTS, 3, 3);
cmsSample3DGrid(AToB0, InputDirection, NULL, 0);
cmsSample3DGrid(BToA0, OutputDirection, NULL, 0);
cmsAddTag(hProfile, icSigAToB0Tag, AToB0);
cmsAddTag(hProfile, icSigBToA0Tag, BToA0);
cmsSetColorSpace(hProfile, icSigLabData);
cmsSetPCS(hProfile, icSigLabData);
cmsSetDeviceClass(hProfile, icSigColorSpaceClass);
cmsAddTag(hProfile, icSigProfileDescriptionTag, "ITU T.42/Fax JPEG CIEL*a*b*");
cmsAddTag(hProfile, icSigCopyrightTag, "No Copyright, use freely.");
cmsAddTag(hProfile, icSigDeviceMfgDescTag, "Little cms");
cmsAddTag(hProfile, icSigDeviceModelDescTag, "ITU T.42/Fax JPEG CIEL*a*b*");
cmsCloseProfile(hProfile);
cmsFreeLUT(AToB0);
cmsFreeLUT(BToA0);
fprintf(stderr, "Done.\n");
return 0;
}
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