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gimp/app/operations/gimpoperationcolorbalance.c
Daniel Baumann 554424e00a
Adding upstream version 3.0.4.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-23 00:14:50 +02:00

248 lines
9.3 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimpoperationcolorbalance.c
* Copyright (C) 2007 Michael Natterer <mitch@gimp.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <cairo.h>
#include <gegl.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include "libgimpcolor/gimpcolor.h"
#include "libgimpmath/gimpmath.h"
#include "operations-types.h"
#include "gimpcolorbalanceconfig.h"
#include "gimpoperationcolorbalance.h"
#include "gimp-intl.h"
static void gimp_operation_color_balance_prepare (GeglOperation *operation);
static gboolean gimp_operation_color_balance_process (GeglOperation *operation,
void *in_buf,
void *out_buf,
glong samples,
const GeglRectangle *roi,
gint level);
G_DEFINE_TYPE (GimpOperationColorBalance, gimp_operation_color_balance,
GIMP_TYPE_OPERATION_POINT_FILTER)
#define parent_class gimp_operation_color_balance_parent_class
static void
gimp_operation_color_balance_class_init (GimpOperationColorBalanceClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GeglOperationClass *operation_class = GEGL_OPERATION_CLASS (klass);
GeglOperationPointFilterClass *point_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
object_class->set_property = gimp_operation_point_filter_set_property;
object_class->get_property = gimp_operation_point_filter_get_property;
gegl_operation_class_set_keys (operation_class,
"name", "gimp:color-balance",
"categories", "color",
"description", _("Adjust color distribution"),
NULL);
operation_class->prepare = gimp_operation_color_balance_prepare;
point_class->process = gimp_operation_color_balance_process;
g_object_class_install_property (object_class,
GIMP_OPERATION_POINT_FILTER_PROP_CONFIG,
g_param_spec_object ("config",
"Config",
"The config object",
GIMP_TYPE_COLOR_BALANCE_CONFIG,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT));
}
static void
gimp_operation_color_balance_init (GimpOperationColorBalance *self)
{
}
static inline gfloat
gimp_operation_color_balance_map (gfloat value,
gfloat lightness,
gfloat shadows,
gfloat midtones,
gfloat highlights)
{
/* Apply masks to the corrections for shadows, midtones and
* highlights so that each correction affects only one range.
* Those masks look like this:
* ‾\___
* _/‾\_
* ___/‾
* with ramps of width a at x = b and x = 1 - b.
*
* The sum of these masks equals 1 for x in 0..1, so applying the
* same correction in the shadows and in the midtones is equivalent
* to applying this correction on a virtual shadows_and_midtones
* range.
*/
static const gfloat a = 0.25f, b = 0.333f, scale = 0.7f;
shadows *= CLAMP ((lightness - b) / -a + 0.5f, 0.f, 1.f) * scale;
midtones *= CLAMP ((lightness - b) / a + 0.5f, 0.f, 1.f) *
CLAMP ((lightness + b - 1.f) / -a + 0.5f, 0.f, 1.f) * scale;
highlights *= CLAMP ((lightness + b - 1.f) / a + 0.5f, 0.f, 1.f) * scale;
value += shadows;
value += midtones;
value += highlights;
/* We are working in sRGB while the image may have a bigger space so
* this CLAMPing will reduce the target space. I'm not sure if
* removing it would be right either.
* This is something to verify and improve in a further version of
* this operation. TODO.
*/
value = CLAMP (value, 0.0f, 1.0f);
return value;
}
static void
gimp_operation_color_balance_prepare (GeglOperation *operation)
{
/* HSV conversion is much faster from sRGB. This version of the
* algorithm will work on sRGB to its respective HSL space.
* TODO: in the future, when babl will have fast conversion for other
* HSV spaces, let's study if we should work in the source space.
*/
const Babl *format = babl_format_with_space ("R'G'B'A float", NULL);
gegl_operation_set_format (operation, "input", format);
gegl_operation_set_format (operation, "output", format);
}
static gboolean
gimp_operation_color_balance_process (GeglOperation *operation,
void *in_buf,
void *out_buf,
glong samples,
const GeglRectangle *roi,
gint level)
{
GimpOperationPointFilter *point = GIMP_OPERATION_POINT_FILTER (operation);
GimpColorBalanceConfig *config = GIMP_COLOR_BALANCE_CONFIG (point->config);
gfloat *src = in_buf;
gfloat *dest = out_buf;
gint total;
const Babl *format;
const Babl *hsl_format;
gfloat *hsl;
gfloat *hsl_p;
gfloat cyan_red_shadows;
gfloat cyan_red_midtones;
gfloat cyan_red_highlights;
gfloat magenta_green_shadows;
gfloat magenta_green_midtones;
gfloat magenta_green_highlights;
gfloat yellow_blue_shadows;
gfloat yellow_blue_midtones;
gfloat yellow_blue_highlights;
gint i;
if (! config)
return FALSE;
cyan_red_shadows = (gfloat) config->cyan_red[GIMP_TRANSFER_SHADOWS];
cyan_red_midtones = (gfloat) config->cyan_red[GIMP_TRANSFER_MIDTONES];
cyan_red_highlights = (gfloat) config->cyan_red[GIMP_TRANSFER_HIGHLIGHTS];
magenta_green_shadows = (gfloat) config->magenta_green[GIMP_TRANSFER_SHADOWS];
magenta_green_midtones = (gfloat) config->magenta_green[GIMP_TRANSFER_MIDTONES];
magenta_green_highlights = (gfloat) config->magenta_green[GIMP_TRANSFER_HIGHLIGHTS];
yellow_blue_shadows = (gfloat) config->yellow_blue[GIMP_TRANSFER_SHADOWS];
yellow_blue_midtones = (gfloat) config->yellow_blue[GIMP_TRANSFER_MIDTONES];
yellow_blue_highlights = (gfloat) config->yellow_blue[GIMP_TRANSFER_HIGHLIGHTS];
total = samples * 4;
format = gegl_operation_get_format (operation, "input");
hsl_format = babl_format_with_space ("HSLA float", NULL);
hsl = g_new0 (gfloat, total);
/* Create HSL buffer */
babl_process (babl_fish (format, hsl_format), in_buf, hsl, samples);
/* Create normalized RGB buffer */
hsl_p = hsl;
for (i = 0; i < samples; i++)
{
gfloat lightness = *(hsl_p + 2);
*dest =
gimp_operation_color_balance_map (*src, lightness,
cyan_red_shadows,
cyan_red_midtones,
cyan_red_highlights);
*(dest + 1) =
gimp_operation_color_balance_map (*(src + 1), lightness,
magenta_green_shadows,
magenta_green_midtones,
magenta_green_highlights);
*(dest + 2) =
gimp_operation_color_balance_map (*(src + 2), lightness,
yellow_blue_shadows,
yellow_blue_midtones,
yellow_blue_highlights);
*(dest + 3) = *(src + 3);
src += 4;
dest += 4;
hsl_p += 4;
}
if (config->preserve_luminosity)
{
gfloat *hsl2 = g_new0 (gfloat, total);
gfloat *hsl2_p;
babl_process (babl_fish (format, hsl_format), out_buf, hsl2, samples);
/* Copy the original lightness value */
hsl_p = hsl;
hsl2_p = hsl2;
for (i = 0; i < samples; i++)
{
*(hsl2_p + 2) = *(hsl_p + 2);
hsl_p += 4;
hsl2_p += 4;
}
babl_process (babl_fish (hsl_format, format), hsl2, out_buf, samples);
g_free (hsl2);
}
g_free (hsl);
return TRUE;
}