Bob Dougherty <bobd@stanford.edu> and Alex Wade <wade@ski.org> added the
2003-01-23 Michael Natterer <mitch@gimp.org> * modules/cdisplay_colorblind.c: Bob Dougherty <bobd@stanford.edu> and Alex Wade <wade@ski.org> added the code needed to make this filter actually do something useful. Thanks for this contribution. Addresses bug #101256.
This commit is contained in:

committed by
Michael Natterer

parent
13b589252c
commit
3f07a7a11b
@ -1,3 +1,10 @@
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2003-01-23 Michael Natterer <mitch@gimp.org>
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* modules/cdisplay_colorblind.c: Bob Dougherty <bobd@stanford.edu>
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and Alex Wade <wade@ski.org> added the code needed to make this
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filter actually do something useful. Thanks for this contribution.
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Addresses bug #101256.
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2003-01-23 Sven Neumann <sven@gimp.org>
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* app/config/gimpcoreconfig.c
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@ -2,7 +2,13 @@
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* Copyright (C) 1995-1997 Spencer Kimball and Peter Mattis
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*
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* cdisplay_colorblind.c
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* Copyright (C) 2002 Michael Natterer <mitch@gimp.org>
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* Copyright (C) 2002-2003 Michael Natterer <mitch@gimp.org>,
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* Robert Dougherty <bob@vischeck.com> and
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* Alex Wade <alex@vischeck.com>
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*
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* This code is an implementation of an algorithm described by Hans Brettel,
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* Francoise Vienot and John Mollon in the Journal of the Optical Society of
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* America V14(10), pg 2647. (See http://vischeck.com/ for more info.)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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@ -29,6 +35,7 @@
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#include "libgimpbase/gimpbase.h"
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#include "libgimpmodule/gimpmodule.h"
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#include "libgimpwidgets/gimpwidgets.h"
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#include "libgimpmath/gimpmath.h"
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#include "libgimp/libgimp-intl.h"
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@ -36,7 +43,7 @@
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typedef enum
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{
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COLORBLIND_DEFICIENCY_NONE,
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COLORBLIND_DEFICIENCY_PROTONOPIA,
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COLORBLIND_DEFICIENCY_PROTANOPIA,
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COLORBLIND_DEFICIENCY_DEUTERANOPIA,
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COLORBLIND_DEFICIENCY_TRITANOPIA,
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COLORBLIND_DEFICIENCY_LAST = COLORBLIND_DEFICIENCY_TRITANOPIA
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@ -98,11 +105,11 @@ static void colorblind_deficiency_callback (GtkWidget *widget
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static const GimpModuleInfo cdisplay_colorblind_info =
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{
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GIMP_MODULE_ABI_VERSION,
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N_("Colorblind display filter"),
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"Michael Natterer <mitch@gimp.org>",
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"v0.1",
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"(c) 2002, released under the GPL",
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"December 16, 2002"
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N_("Color deficit simulation filter (Brettel-Vienot-Mollon algorithm)"),
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"Michael Natterer <mitch@gimp.org>, Bob Dougherty <bob@vischeck.com>, Alex Wade <alex@vischeck.com>",
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"v0.2",
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"(c) 2002-2003, released under the GPL",
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"January 22, 2003"
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};
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static GType cdisplay_colorblind_type = 0;
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@ -131,14 +138,14 @@ cdisplay_colorblind_get_type (GTypeModule *module)
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static const GTypeInfo display_info =
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{
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sizeof (CdisplayColorblindClass),
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(GBaseInitFunc) NULL,
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(GBaseFinalizeFunc) NULL,
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(GClassInitFunc) cdisplay_colorblind_class_init,
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NULL, /* class_finalize */
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NULL, /* class_data */
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sizeof (CdisplayColorblind),
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0, /* n_preallocs */
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(GInstanceInitFunc) cdisplay_colorblind_init,
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(GBaseInitFunc) NULL,
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(GBaseFinalizeFunc) NULL,
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(GClassInitFunc) cdisplay_colorblind_class_init,
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NULL, /* class_finalize */
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NULL, /* class_data */
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sizeof (CdisplayColorblind),
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0, /* n_preallocs */
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(GInstanceInitFunc) cdisplay_colorblind_init,
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};
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cdisplay_colorblind_type =
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@ -218,52 +225,190 @@ cdisplay_colorblind_convert (GimpColorDisplay *display,
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gint bpl)
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{
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CdisplayColorblind *colorblind;
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gint i, j;
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gint i;
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guchar *b;
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gfloat rgb2lms[9],lms2rgb[9],gammaRGB[3],anchor_e[3],anchor[12];
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gfloat a1, b1, c1, a2, b2, c2, inflectionVal, tmp;
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gfloat red, green, blue, redOld, greenOld; /* Hold rgb values extracted from the buffer */
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gint npix; /* Number of pixels in the image */
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colorblind = CDISPLAY_COLORBLIND (display);
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/* Require 3 bytes per pixel (assume RGB) */
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if (bpp != 3)
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return;
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j = height;
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/* For most modern Cathode-Ray Tube monitors (CRTs), the following
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* are good estimates of the RGB->LMS and LMS->RGB transform
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* matrices. They are based on spectra measured on a typical CRT
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* with a PhotoResearch PR650 spectral photometer and the Stockman
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* human cone fundamentals. NOTE: these estimates will NOT work well
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* for LCDs!
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*/
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rgb2lms[0] = 0.05059983; rgb2lms[1] = 0.08585369; rgb2lms[2] = 0.00952420;
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rgb2lms[3] = 0.01893033; rgb2lms[4] = 0.08925308; rgb2lms[5] = 0.01370054;
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rgb2lms[6] = 0.00292202; rgb2lms[7] = 0.00975732; rgb2lms[8] = 0.07145979;
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while (j--)
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lms2rgb[0] = 30.830854; lms2rgb[1] = -29.832659; lms2rgb[2] = 1.610474;
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lms2rgb[3] = -6.481468; lms2rgb[4] = 17.715578; lms2rgb[5] = -2.532642;
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lms2rgb[6] = -0.375690; lms2rgb[7] = -1.199062; lms2rgb[8] = 14.273846;
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/* The RGB<->LMS transforms above are computed from the human cone
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* photo-pigment absorption spectra and the monitor phosphor
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* emission spectra. These parameters are fairly constant for most
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* humans and most montiors (at least for modern CRTs). However,
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* gamma will vary quite a bit, as it is a property of the monitor
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* (eg. amplifier gain), the video card, and even the
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* software. Further, users can adjust their gammas (either via
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* adjusting the monitor amp gains or in software). That said, the
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* following are the gamma estimates that we have used in the
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* Vischeck code. Many colorblind users have viewed our simulations
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* and told us that they "work" (simulated and original images are
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* indistinguishabled).
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*/
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gammaRGB[0] = 2.1;
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gammaRGB[1] = 2.0;
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gammaRGB[2] = 2.1;
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/* Performs protan, deutan or tritan color image simulation based on
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* Brettel, Vienot and Mollon JOSA 14/10 1997
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* L,M,S for lambda=475,485,575,660
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*
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* Load the LMS anchor-point values for lambda = 475 & 485 nm (for
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* protans & deutans) and the LMS values for lambda = 575 & 660 nm
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* (for tritans)
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*/
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anchor[0] = 0.08008; anchor[1] = 0.1579; anchor[2] = 0.5897;
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anchor[3] = 0.1284; anchor[4] = 0.2237; anchor[5] = 0.3636;
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anchor[6] = 0.9856; anchor[7] = 0.7325; anchor[8] = 0.001079;
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anchor[9] = 0.0914; anchor[10] = 0.007009; anchor[11] = 0.0;
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/* We also need LMS for RGB=(1,1,1)- the equal-energy point (one of
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* our anchors) (we can just peel this out of the rgb2lms transform
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* matrix)
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*/
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anchor_e[0] = rgb2lms[0] + rgb2lms[1] + rgb2lms[2];
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anchor_e[1] = rgb2lms[3] + rgb2lms[4] + rgb2lms[5];
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anchor_e[2] = rgb2lms[6] + rgb2lms[7] + rgb2lms[8];
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switch (colorblind->deficiency)
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{
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i = width;
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b = buf;
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default:
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case COLORBLIND_DEFICIENCY_DEUTERANOPIA:
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/* find a,b,c for lam=575nm and lam=475 */
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a1 = anchor_e[1] * anchor[8] - anchor_e[2] * anchor[7];
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b1 = anchor_e[2] * anchor[6] - anchor_e[0] * anchor[8];
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c1 = anchor_e[0] * anchor[7] - anchor_e[1] * anchor[6];
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a2 = anchor_e[1] * anchor[2] - anchor_e[2] * anchor[1];
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b2 = anchor_e[2] * anchor[0] - anchor_e[0] * anchor[2];
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c2 = anchor_e[0] * anchor[1] - anchor_e[1] * anchor[0];
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inflectionVal = (anchor_e[2] / anchor_e[0]);
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break;
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case COLORBLIND_DEFICIENCY_PROTANOPIA:
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/* find a,b,c for lam=575nm and lam=475 */
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a1 = anchor_e[1] * anchor[8] - anchor_e[2] * anchor[7];
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b1 = anchor_e[2] * anchor[6] - anchor_e[0] * anchor[8];
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c1 = anchor_e[0] * anchor[7] - anchor_e[1] * anchor[6];
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a2 = anchor_e[1] * anchor[2] - anchor_e[2] * anchor[1];
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b2 = anchor_e[2] * anchor[0] - anchor_e[0] * anchor[2];
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c2 = anchor_e[0] * anchor[1] - anchor_e[1] * anchor[0];
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inflectionVal = (anchor_e[2] / anchor_e[1]);
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break;
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case COLORBLIND_DEFICIENCY_TRITANOPIA:
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/* Set 1: regions where lambda_a=575, set 2: lambda_a=475 */
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a1 = anchor_e[1] * anchor[11] - anchor_e[2] * anchor[10];
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b1 = anchor_e[2] * anchor[9] - anchor_e[0] * anchor[11];
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c1 = anchor_e[0] * anchor[10] - anchor_e[1] * anchor[9];
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a2 = anchor_e[1] * anchor[5] - anchor_e[2] * anchor[4];
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b2 = anchor_e[2] * anchor[3] - anchor_e[0] * anchor[5];
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c2 = anchor_e[0] * anchor[4] - anchor_e[1] * anchor[3];
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inflectionVal = (anchor_e[1] / anchor_e[0]);
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break;
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}
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npix = height * width;
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b = buf; /* pointer to the RGB color buffer */
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for (i = npix - 1; i >= 0; i--)
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{
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red = b[0];
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green = b[1];
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blue = b[2];
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/* Remove gamma to linearize RGB intensities */
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red = pow (red, 1.0 / gammaRGB[0]);
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green = pow (green, 1.0 / gammaRGB[1]);
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blue = pow (blue, 1.0 / gammaRGB[2]);
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/* Convert to LMS (dot product with transform matrix) */
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redOld = red;
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greenOld = green;
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red = redOld * rgb2lms[0] + greenOld * rgb2lms[1] + blue * rgb2lms[2];
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green = redOld * rgb2lms[3] + greenOld * rgb2lms[4] + blue * rgb2lms[5];
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blue = redOld * rgb2lms[6] + greenOld * rgb2lms[7] + blue * rgb2lms[8];
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switch (colorblind->deficiency)
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{
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case COLORBLIND_DEFICIENCY_PROTONOPIA:
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case COLORBLIND_DEFICIENCY_DEUTERANOPIA:
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/* FIXME: need proper formulas */
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while (i--)
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{
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guchar red = b[0] >> 1;
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guchar green = b[1] >> 1;
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case COLORBLIND_DEFICIENCY_DEUTERANOPIA:
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tmp = blue / red;
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/* See which side of the inflection line we fall... */
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if (tmp < inflectionVal)
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green = -(a1 * red + c1 * blue) / b1;
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else
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green = -(a2 * red + c2 * blue) / b2;
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break;
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b[0] = b[1] = red + green;
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b += bpp;
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}
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case COLORBLIND_DEFICIENCY_PROTANOPIA:
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tmp = blue / green;
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/* See which side of the inflection line we fall... */
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if (tmp < inflectionVal)
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red = -(b1 * green + c1 * blue) / a1;
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else
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red = -(b2 * green + c2 * blue) / a2;
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break;
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case COLORBLIND_DEFICIENCY_TRITANOPIA:
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/* FIXME: need proper formula */
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while (i--)
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{
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b[2] = 0;
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b += bpp;
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}
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tmp = green / red;
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/* See which side of the inflection line we fall... */
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if (tmp < inflectionVal)
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blue = -(a1 * red + b1 * green) / c1;
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else
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blue = -(a2 * red + b2 * green) / c2;
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break;
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default:
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break;
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}
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buf += bpl;
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/* Convert back to RGB (cross product with transform matrix) */
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redOld = red;
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greenOld = green;
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red = redOld * lms2rgb[0] + greenOld * lms2rgb[1] + blue * lms2rgb[2];
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green = redOld * lms2rgb[3] + greenOld * lms2rgb[4] + blue * lms2rgb[5];
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blue = redOld * lms2rgb[6] + greenOld * lms2rgb[7] + blue * lms2rgb[8];
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/* Apply gamma to go back to non-linear intensities */
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red = pow (red, gammaRGB[0]);
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green = pow (green, gammaRGB[1]);
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blue = pow (blue, gammaRGB[2]);
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/* Ensure that we stay within the RGB gamut */
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/* *** FIX THIS: it would be better to desaturate than blindly clip. */
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red = CLAMP (red, 0, 255);
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green = CLAMP (green, 0, 255);
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blue = CLAMP (blue, 0, 255);
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/* Stuff result back into buffer */
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b[0] = (guchar) red;
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b[1] = (guchar) green;
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b[2] = (guchar) blue;
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/* Increment b by the number of bytes per pixel. */
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b += bpp;
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}
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}
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@ -306,7 +451,7 @@ cdisplay_colorblind_save_state (GimpColorDisplay *display)
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g_snprintf (buf, sizeof (buf), "%d", colorblind->deficiency);
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return gimp_parasite_new ("Display/Colorblind", GIMP_PARASITE_PERSISTENT,
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strlen (buf) + 1, buf);
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strlen (buf) + 1, buf);
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}
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static GtkWidget *
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@ -334,8 +479,8 @@ cdisplay_colorblind_configure (GimpColorDisplay *display)
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colorblind,
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GINT_TO_POINTER (colorblind->deficiency),
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_("Protonopia (insensitivity to red)"),
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GINT_TO_POINTER (COLORBLIND_DEFICIENCY_PROTONOPIA),
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_("Protanopia (insensitivity to red)"),
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GINT_TO_POINTER (COLORBLIND_DEFICIENCY_PROTANOPIA),
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NULL,
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_("Deuteranopia (insensitivity to green)"),
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Reference in New Issue
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