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Diffstat (limited to 'app/operations/gimpoperationcolorbalance.c')
| -rw-r--r-- | app/operations/gimpoperationcolorbalance.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/app/operations/gimpoperationcolorbalance.c b/app/operations/gimpoperationcolorbalance.c new file mode 100644 index 0000000..9988158 --- /dev/null +++ b/app/operations/gimpoperationcolorbalance.c @@ -0,0 +1,198 @@ +/* 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 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); + + 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, + gdouble lightness, + gdouble shadows, + gdouble midtones, + gdouble 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 gdouble a = 0.25, b = 0.333, scale = 0.7; + + shadows *= CLAMP ((lightness - b) / -a + 0.5, 0, 1) * scale; + midtones *= CLAMP ((lightness - b) / a + 0.5, 0, 1) * + CLAMP ((lightness + b - 1) / -a + 0.5, 0, 1) * scale; + highlights *= CLAMP ((lightness + b - 1) / a + 0.5, 0, 1) * scale; + + value += shadows; + value += midtones; + value += highlights; + value = CLAMP (value, 0.0, 1.0); + + return value; +} + +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; + + if (! config) + return FALSE; + + while (samples--) + { + gfloat r = src[RED]; + gfloat g = src[GREEN]; + gfloat b = src[BLUE]; + gfloat r_n; + gfloat g_n; + gfloat b_n; + + GimpRGB rgb = { r, g, b}; + GimpHSL hsl; + + gimp_rgb_to_hsl (&rgb, &hsl); + + r_n = gimp_operation_color_balance_map (r, hsl.l, + config->cyan_red[GIMP_TRANSFER_SHADOWS], + config->cyan_red[GIMP_TRANSFER_MIDTONES], + config->cyan_red[GIMP_TRANSFER_HIGHLIGHTS]); + + g_n = gimp_operation_color_balance_map (g, hsl.l, + config->magenta_green[GIMP_TRANSFER_SHADOWS], + config->magenta_green[GIMP_TRANSFER_MIDTONES], + config->magenta_green[GIMP_TRANSFER_HIGHLIGHTS]); + + b_n = gimp_operation_color_balance_map (b, hsl.l, + config->yellow_blue[GIMP_TRANSFER_SHADOWS], + config->yellow_blue[GIMP_TRANSFER_MIDTONES], + config->yellow_blue[GIMP_TRANSFER_HIGHLIGHTS]); + + if (config->preserve_luminosity) + { + GimpHSL hsl2; + + rgb.r = r_n; + rgb.g = g_n; + rgb.b = b_n; + gimp_rgb_to_hsl (&rgb, &hsl); + + rgb.r = r; + rgb.g = g; + rgb.b = b; + gimp_rgb_to_hsl (&rgb, &hsl2); + + hsl.l = hsl2.l; + + gimp_hsl_to_rgb (&hsl, &rgb); + + r_n = rgb.r; + g_n = rgb.g; + b_n = rgb.b; + } + + dest[RED] = r_n; + dest[GREEN] = g_n; + dest[BLUE] = b_n; + dest[ALPHA] = src[ALPHA]; + + src += 4; + dest += 4; + } + + return TRUE; +} |