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authorQt by Nokia <qt-info@nokia.com>2011-04-27 12:05:43 +0200
committeraxis <qt-info@nokia.com>2011-04-27 12:05:43 +0200
commit38be0d13830efd2d98281c645c3a60afe05ffece (patch)
tree6ea73f3ec77f7d153333779883e8120f82820abe /src/3rdparty/libtiff/libtiff/tif_color.c
Initial import from the monolithic Qt.
This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12
Diffstat (limited to 'src/3rdparty/libtiff/libtiff/tif_color.c')
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diff --git a/src/3rdparty/libtiff/libtiff/tif_color.c b/src/3rdparty/libtiff/libtiff/tif_color.c
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+/* $Id: tif_color.c,v 1.12 2006/02/09 15:42:20 dron Exp $ */
+
+/*
+ * Copyright (c) 1988-1997 Sam Leffler
+ * Copyright (c) 1991-1997 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the names of
+ * Sam Leffler and Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Sam Leffler and Silicon Graphics.
+ *
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+/*
+ * CIE L*a*b* to CIE XYZ and CIE XYZ to RGB conversion routines are taken
+ * from the VIPS library (http://www.vips.ecs.soton.ac.uk) with
+ * the permission of John Cupitt, the VIPS author.
+ */
+
+/*
+ * TIFF Library.
+ *
+ * Color space conversion routines.
+ */
+
+#include "tiffiop.h"
+#include <math.h>
+
+/*
+ * Convert color value from the CIE L*a*b* 1976 space to CIE XYZ.
+ */
+void
+TIFFCIELabToXYZ(TIFFCIELabToRGB *cielab, uint32 l, int32 a, int32 b,
+ float *X, float *Y, float *Z)
+{
+ float L = (float)l * 100.0F / 255.0F;
+ float cby, tmp;
+
+ if( L < 8.856F ) {
+ *Y = (L * cielab->Y0) / 903.292F;
+ cby = 7.787F * (*Y / cielab->Y0) + 16.0F / 116.0F;
+ } else {
+ cby = (L + 16.0F) / 116.0F;
+ *Y = cielab->Y0 * cby * cby * cby;
+ }
+
+ tmp = (float)a / 500.0F + cby;
+ if( tmp < 0.2069F )
+ *X = cielab->X0 * (tmp - 0.13793F) / 7.787F;
+ else
+ *X = cielab->X0 * tmp * tmp * tmp;
+
+ tmp = cby - (float)b / 200.0F;
+ if( tmp < 0.2069F )
+ *Z = cielab->Z0 * (tmp - 0.13793F) / 7.787F;
+ else
+ *Z = cielab->Z0 * tmp * tmp * tmp;
+}
+
+#define RINT(R) ((uint32)((R)>0?((R)+0.5):((R)-0.5)))
+/*
+ * Convert color value from the XYZ space to RGB.
+ */
+void
+TIFFXYZToRGB(TIFFCIELabToRGB *cielab, float X, float Y, float Z,
+ uint32 *r, uint32 *g, uint32 *b)
+{
+ int i;
+ float Yr, Yg, Yb;
+ float *matrix = &cielab->display.d_mat[0][0];
+
+ /* Multiply through the matrix to get luminosity values. */
+ Yr = matrix[0] * X + matrix[1] * Y + matrix[2] * Z;
+ Yg = matrix[3] * X + matrix[4] * Y + matrix[5] * Z;
+ Yb = matrix[6] * X + matrix[7] * Y + matrix[8] * Z;
+
+ /* Clip input */
+ Yr = TIFFmax(Yr, cielab->display.d_Y0R);
+ Yg = TIFFmax(Yg, cielab->display.d_Y0G);
+ Yb = TIFFmax(Yb, cielab->display.d_Y0B);
+
+ /* Avoid overflow in case of wrong input values */
+ Yr = TIFFmin(Yr, cielab->display.d_YCR);
+ Yg = TIFFmin(Yg, cielab->display.d_YCG);
+ Yb = TIFFmin(Yb, cielab->display.d_YCB);
+
+ /* Turn luminosity to colour value. */
+ i = (int)((Yr - cielab->display.d_Y0R) / cielab->rstep);
+ i = TIFFmin(cielab->range, i);
+ *r = RINT(cielab->Yr2r[i]);
+
+ i = (int)((Yg - cielab->display.d_Y0G) / cielab->gstep);
+ i = TIFFmin(cielab->range, i);
+ *g = RINT(cielab->Yg2g[i]);
+
+ i = (int)((Yb - cielab->display.d_Y0B) / cielab->bstep);
+ i = TIFFmin(cielab->range, i);
+ *b = RINT(cielab->Yb2b[i]);
+
+ /* Clip output. */
+ *r = TIFFmin(*r, cielab->display.d_Vrwr);
+ *g = TIFFmin(*g, cielab->display.d_Vrwg);
+ *b = TIFFmin(*b, cielab->display.d_Vrwb);
+}
+#undef RINT
+
+/*
+ * Allocate conversion state structures and make look_up tables for
+ * the Yr,Yb,Yg <=> r,g,b conversions.
+ */
+int
+TIFFCIELabToRGBInit(TIFFCIELabToRGB* cielab,
+ TIFFDisplay *display, float *refWhite)
+{
+ int i;
+ double gamma;
+
+ cielab->range = CIELABTORGB_TABLE_RANGE;
+
+ _TIFFmemcpy(&cielab->display, display, sizeof(TIFFDisplay));
+
+ /* Red */
+ gamma = 1.0 / cielab->display.d_gammaR ;
+ cielab->rstep =
+ (cielab->display.d_YCR - cielab->display.d_Y0R) / cielab->range;
+ for(i = 0; i <= cielab->range; i++) {
+ cielab->Yr2r[i] = cielab->display.d_Vrwr
+ * ((float)pow((double)i / cielab->range, gamma));
+ }
+
+ /* Green */
+ gamma = 1.0 / cielab->display.d_gammaG ;
+ cielab->gstep =
+ (cielab->display.d_YCR - cielab->display.d_Y0R) / cielab->range;
+ for(i = 0; i <= cielab->range; i++) {
+ cielab->Yg2g[i] = cielab->display.d_Vrwg
+ * ((float)pow((double)i / cielab->range, gamma));
+ }
+
+ /* Blue */
+ gamma = 1.0 / cielab->display.d_gammaB ;
+ cielab->bstep =
+ (cielab->display.d_YCR - cielab->display.d_Y0R) / cielab->range;
+ for(i = 0; i <= cielab->range; i++) {
+ cielab->Yb2b[i] = cielab->display.d_Vrwb
+ * ((float)pow((double)i / cielab->range, gamma));
+ }
+
+ /* Init reference white point */
+ cielab->X0 = refWhite[0];
+ cielab->Y0 = refWhite[1];
+ cielab->Z0 = refWhite[2];
+
+ return 0;
+}
+
+/*
+ * Convert color value from the YCbCr space to CIE XYZ.
+ * The colorspace conversion algorithm comes from the IJG v5a code;
+ * see below for more information on how it works.
+ */
+#define SHIFT 16
+#define FIX(x) ((int32)((x) * (1L<<SHIFT) + 0.5))
+#define ONE_HALF ((int32)(1<<(SHIFT-1)))
+#define Code2V(c, RB, RW, CR) ((((c)-(int32)(RB))*(float)(CR))/(float)(((RW)-(RB)) ? ((RW)-(RB)) : 1))
+#define CLAMP(f,min,max) ((f)<(min)?(min):(f)>(max)?(max):(f))
+#define HICLAMP(f,max) ((f)>(max)?(max):(f))
+
+void
+TIFFYCbCrtoRGB(TIFFYCbCrToRGB *ycbcr, uint32 Y, int32 Cb, int32 Cr,
+ uint32 *r, uint32 *g, uint32 *b)
+{
+ /* XXX: Only 8-bit YCbCr input supported for now */
+ Y = HICLAMP(Y, 255), Cb = CLAMP(Cb, 0, 255), Cr = CLAMP(Cr, 0, 255);
+
+ *r = ycbcr->clamptab[ycbcr->Y_tab[Y] + ycbcr->Cr_r_tab[Cr]];
+ *g = ycbcr->clamptab[ycbcr->Y_tab[Y]
+ + (int)((ycbcr->Cb_g_tab[Cb] + ycbcr->Cr_g_tab[Cr]) >> SHIFT)];
+ *b = ycbcr->clamptab[ycbcr->Y_tab[Y] + ycbcr->Cb_b_tab[Cb]];
+}
+
+/*
+ * Initialize the YCbCr->RGB conversion tables. The conversion
+ * is done according to the 6.0 spec:
+ *
+ * R = Y + Cr*(2 - 2*LumaRed)
+ * B = Y + Cb*(2 - 2*LumaBlue)
+ * G = Y
+ * - LumaBlue*Cb*(2-2*LumaBlue)/LumaGreen
+ * - LumaRed*Cr*(2-2*LumaRed)/LumaGreen
+ *
+ * To avoid floating point arithmetic the fractional constants that
+ * come out of the equations are represented as fixed point values
+ * in the range 0...2^16. We also eliminate multiplications by
+ * pre-calculating possible values indexed by Cb and Cr (this code
+ * assumes conversion is being done for 8-bit samples).
+ */
+int
+TIFFYCbCrToRGBInit(TIFFYCbCrToRGB* ycbcr, float *luma, float *refBlackWhite)
+{
+ TIFFRGBValue* clamptab;
+ int i;
+
+#define LumaRed luma[0]
+#define LumaGreen luma[1]
+#define LumaBlue luma[2]
+
+ clamptab = (TIFFRGBValue*)(
+ (tidata_t) ycbcr+TIFFroundup(sizeof (TIFFYCbCrToRGB), sizeof (long)));
+ _TIFFmemset(clamptab, 0, 256); /* v < 0 => 0 */
+ ycbcr->clamptab = (clamptab += 256);
+ for (i = 0; i < 256; i++)
+ clamptab[i] = (TIFFRGBValue) i;
+ _TIFFmemset(clamptab+256, 255, 2*256); /* v > 255 => 255 */
+ ycbcr->Cr_r_tab = (int*) (clamptab + 3*256);
+ ycbcr->Cb_b_tab = ycbcr->Cr_r_tab + 256;
+ ycbcr->Cr_g_tab = (int32*) (ycbcr->Cb_b_tab + 256);
+ ycbcr->Cb_g_tab = ycbcr->Cr_g_tab + 256;
+ ycbcr->Y_tab = ycbcr->Cb_g_tab + 256;
+
+ { float f1 = 2-2*LumaRed; int32 D1 = FIX(f1);
+ float f2 = LumaRed*f1/LumaGreen; int32 D2 = -FIX(f2);
+ float f3 = 2-2*LumaBlue; int32 D3 = FIX(f3);
+ float f4 = LumaBlue*f3/LumaGreen; int32 D4 = -FIX(f4);
+ int x;
+
+#undef LumaBlue
+#undef LumaGreen
+#undef LumaRed
+
+ /*
+ * i is the actual input pixel value in the range 0..255
+ * Cb and Cr values are in the range -128..127 (actually
+ * they are in a range defined by the ReferenceBlackWhite
+ * tag) so there is some range shifting to do here when
+ * constructing tables indexed by the raw pixel data.
+ */
+ for (i = 0, x = -128; i < 256; i++, x++) {
+ int32 Cr = (int32)Code2V(x, refBlackWhite[4] - 128.0F,
+ refBlackWhite[5] - 128.0F, 127);
+ int32 Cb = (int32)Code2V(x, refBlackWhite[2] - 128.0F,
+ refBlackWhite[3] - 128.0F, 127);
+
+ ycbcr->Cr_r_tab[i] = (int32)((D1*Cr + ONE_HALF)>>SHIFT);
+ ycbcr->Cb_b_tab[i] = (int32)((D3*Cb + ONE_HALF)>>SHIFT);
+ ycbcr->Cr_g_tab[i] = D2*Cr;
+ ycbcr->Cb_g_tab[i] = D4*Cb + ONE_HALF;
+ ycbcr->Y_tab[i] =
+ (int32)Code2V(x + 128, refBlackWhite[0], refBlackWhite[1], 255);
+ }
+ }
+
+ return 0;
+}
+#undef HICLAMP
+#undef CLAMP
+#undef Code2V
+#undef SHIFT
+#undef ONE_HALF
+#undef FIX
+
+/* vim: set ts=8 sts=8 sw=8 noet: */