tonemap.cc

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/*
    This file is part of darktable,
    Copyright (C) 2010-2011 Bruce Guenter.
    Copyright (C) 2010-2012 Henrik Andersson.
    Copyright (C) 2010-2013, 2016 johannes hanika.
    Copyright (C) 2010 Thierry Leconte.
    Copyright (C) 2011 Jérémy Rosen.
    Copyright (C) 2011 Olivier Tribout.
    Copyright (C) 2011 Robert Bieber.
    Copyright (C) 2011-2014, 2016, 2019 Tobias Ellinghaus.
    Copyright (C) 2012 John Sheu.
    Copyright (C) 2012 Richard Wonka.
    Copyright (C) 2012, 2014 Ulrich Pegelow.
    Copyright (C) 2013 Simon Spannagel.
    Copyright (C) 2014-2016 Roman Lebedev.
    Copyright (C) 2017 Heiko Bauke.
    Copyright (C) 2018, 2020, 2023, 2025-2026 Aurélien PIERRE.
    Copyright (C) 2018 Edgardo Hoszowski.
    Copyright (C) 2018 Maurizio Paglia.
    Copyright (C) 2018, 2020-2021 Pascal Obry.
    Copyright (C) 2018 rawfiner.
    Copyright (C) 2019 luzpaz.
    Copyright (C) 2020 Aldric Renaudin.
    Copyright (C) 2020, 2022 Diederik Ter Rahe.
    Copyright (C) 2020 Ralf Brown.
    Copyright (C) 2021 Chris Elston.
    Copyright (C) 2022 Martin Bařinka.
    Copyright (C) 2022 Philipp Lutz.
    Copyright (C) 2025 Alynx Zhou.
    
    darktable 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.
    
    darktable 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 darktable.  If not, see <http://www.gnu.org/licenses/>.
*/
 
//
// A tonemapping module using Durand's process :
// <http://graphics.lcs.mit.edu/~fredo/PUBLI/Siggraph2002/>
//
// Use andrew adams et al.'s permutohedral lattice, for fast bilateral filtering
// See Permutohedral.h
//
 
#define __STDC_FORMAT_MACROS
 
#include "glib.h"
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
 
#include "bauhaus/bauhaus.h"
#include "control/control.h"
#include "develop/develop.h"
#include "develop/imageop.h"
#include "develop/imageop_gui.h"
 
#include "gui/gtk.h"
#include "iop/iop_api.h"
#include <gtk/gtk.h>
#include <inttypes.h>
 
 
#include "iop/Permutohedral.h"
 
extern "C" {
DT_MODULE_INTROSPECTION(1, dt_iop_tonemapping_params_t)
 
typedef struct dt_iop_tonemapping_params_t
{
  float contrast; // $MIN: 1.0 $MAX: 5.0 $DEFAULT: 2.5 $DESCRIPTION: "contrast compression"
  float Fsize;    // $MIN: 0.0 $MAX: 100.0 $DEFAULT: 30 $DESCRIPTION: "spatial extent"
} dt_iop_tonemapping_params_t;
 
typedef struct dt_iop_tonemapping_gui_data_t
{
  GtkWidget *contrast, *Fsize;
} dt_iop_tonemapping_gui_data_t;
 
typedef struct dt_iop_tonemapping_data_t
{
  float contrast, Fsize;
} dt_iop_tonemapping_data_t;
 
const char *name()
{
  return _("tone mapping");
}
 
 
int default_group()
{
  return IOP_GROUP_TONES;
}
 
int flags()
{
  return IOP_FLAGS_SUPPORTS_BLENDING | IOP_FLAGS_DEPRECATED;
}
 
const char *deprecated_msg()
{
  return _("this module is deprecated. please use the local contrast or tone equalizer module instead.");
}
 
int default_colorspace(dt_iop_module_t *self, dt_dev_pixelpipe_t *pipe, const dt_dev_pixelpipe_iop_t *piece)
{
  return IOP_CS_RGB;
}
 
void output_format(dt_iop_module_t *self, dt_dev_pixelpipe_t *pipe, dt_dev_pixelpipe_iop_t *piece,
                   dt_iop_buffer_dsc_t *dsc)
{
  default_output_format(self, pipe, piece, dsc);
}
 
__DT_CLONE_TARGETS__
int process(struct dt_iop_module_t *self, const dt_dev_pixelpipe_t *pipe, const dt_dev_pixelpipe_iop_t *piece, const void *const ivoid,
             void *const ovoid)
{
  const dt_iop_roi_t *const roi_in = &piece->roi_in;
  const dt_iop_roi_t *const roi_out = &piece->roi_out;
  dt_iop_tonemapping_data_t *data = (dt_iop_tonemapping_data_t *)piece->data;
  const int ch = piece->dsc_in.channels;
 
  int width, height;
  float inv_sigma_s;
  const float inv_sigma_r = 1.0 / 0.4;
 
  width = roi_in->width;
  height = roi_in->height;
  const size_t size = (size_t)width * height;
  const float iw = piece->buf_in.width * roi_out->scale;
  const float ih = piece->buf_in.height * roi_out->scale;
 
  inv_sigma_s = (data->Fsize / 100.0) * fminf(iw, ih);
  if(inv_sigma_s < 3.0) inv_sigma_s = 3.0;
  inv_sigma_s = 1.0 / inv_sigma_s;
 
  PermutohedralLattice<3, 2> lattice(size, omp_get_max_threads());
 
// Build I=log(L)
// and splat into the lattice
#ifdef _OPENMP
#pragma omp parallel for shared(lattice)
#endif
  for(int j = 0; j < height; j++)
  {
    size_t index = (size_t)j * width;
    const int thread = omp_get_thread_num();
    const float *in = (const float *)ivoid + (size_t)j * width * ch;
    for(int i = 0; i < width; i++, index++, in += ch)
    {
      float L = 0.2126 * in[0] + 0.7152 * in[1] + 0.0722 * in[2];
      if(L <= 0.0) L = 1e-6;
      L = logf(L);
      float pos[3] = { i * inv_sigma_s, j * inv_sigma_s, L * inv_sigma_r };
      float val[2] = { L, 1.0 };
      lattice.splat(pos, val, index, thread);
    }
  }
 
  lattice.merge_splat_threads();
 
  // blur the lattice
  lattice.blur();
 
  //
  // Durand process :
  // r=R/(input intensity), g=G/input intensity, B=B/input intensity
  // log(base)=Bilateral(log(input intensity))
  // log(detail)=log(input intensity)-log(base)
  // log (output intensity)=log(base)*compressionfactor+log(detail)
  // R output = r*exp(log(output intensity)), etc.
  //
  // Simplyfing :
  // R output = R/(input intensity)*exp(log(output intensity))
  //          = R*exp(log(output intensity)-log(input intensity))
  //          = R*exp(log(base)*compressionfactor+log(input intensity)-log(base)-log(input intensity))
  //          = R*exp(log(base)*(compressionfactor-1))
  //
  // Plus :
  //  Before compressing the base intensity , we remove average base intensity in order to not have
  //  variable average intensity when varying compression factor.
  //  after compression we subtract 2.0 to have an average intensity at middle tone.
  //
 
  const float contr = 1. / data->contrast;
#ifdef _OPENMP
#pragma omp parallel for
#endif
  for(int j = 0; j < height; j++)
  {
    size_t index = (size_t)j * width;
    const float *in = (const float *)ivoid + (size_t)j * width * ch;
    float *out = (float *)ovoid + (size_t)j * width * ch;
    for(int i = 0; i < width; i++, index++, in += ch, out += ch)
    {
      float val[2];
      lattice.slice(val, index);
      float L = 0.2126 * in[0] + 0.7152 * in[1] + 0.0722 * in[2];
      if(L <= 0.0) L = 1e-6;
      L = logf(L);
      const float B = val[0] / val[1];
      const float detail = L - B;
      const float Ln = expf(B * (contr - 1.0f) + detail - 1.0f);
 
      out[0] = in[0] * Ln;
      out[1] = in[1] * Ln;
      out[2] = in[2] * Ln;
      out[3] = in[3];
    }
  }
  return 0;
}
 
 
// GUI
//
void commit_params(struct dt_iop_module_t *self, dt_iop_params_t *p1, dt_dev_pixelpipe_t *pipe,
                   dt_dev_pixelpipe_iop_t *piece)
{
  dt_iop_tonemapping_params_t *p = (dt_iop_tonemapping_params_t *)p1;
  dt_iop_tonemapping_data_t *d = (dt_iop_tonemapping_data_t *)piece->data;
  d->contrast = p->contrast;
  d->Fsize = p->Fsize;
 
  const float contr = 1.0f / d->contrast;
  float L = 0.2126f * piece->dsc_in.processed_maximum[0]
          + 0.7152f * piece->dsc_in.processed_maximum[1]
          + 0.0722f * piece->dsc_in.processed_maximum[2];
  if(L <= 0.0f) L = 1e-6f;
  L = logf(L);
 
  const float Ln = expf(L * (contr - 1.0f) - 1.0f);
  for(int k = 0; k < 3; k++) piece->dsc_out.processed_maximum[k] = piece->dsc_in.processed_maximum[k] * Ln;
}
 
void init_pipe(struct dt_iop_module_t *self, dt_dev_pixelpipe_t *pipe, dt_dev_pixelpipe_iop_t *piece)
{
  piece->data = dt_calloc_align(sizeof(dt_iop_tonemapping_data_t));
  piece->data_size = sizeof(dt_iop_tonemapping_data_t);
}
 
void cleanup_pipe(struct dt_iop_module_t *self, dt_dev_pixelpipe_t *pipe, dt_dev_pixelpipe_iop_t *piece)
{
  dt_free_align(piece->data);
  piece->data = NULL;
}
 
void gui_init(struct dt_iop_module_t *self)
{
  dt_iop_tonemapping_gui_data_t *g = IOP_GUI_ALLOC(tonemapping);
 
  g->contrast = dt_bauhaus_slider_from_params(self, "contrast");
 
  g->Fsize = dt_bauhaus_slider_from_params(self, "Fsize");
  dt_bauhaus_slider_set_format(g->Fsize, "%");
}
}
 
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// modelines: These editor modelines have been set for all relevant files by tools/update_modelines.py
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