common/histogram.c

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/*
    This file is part of darktable,
    Copyright (C) 2014-2016 Roman Lebedev.
    Copyright (C) 2014, 2016 Tobias Ellinghaus.
    Copyright (C) 2018-2019 Edgardo Hoszowski.
    Copyright (C) 2019 Andreas Schneider.
    Copyright (C) 2020 Pascal Obry.
    Copyright (C) 2021 Ralf Brown.
    Copyright (C) 2022 Martin Bařinka.
    Copyright (C) 2022 Philipp Lutz.
    
    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/>.
*/
#include <math.h>
#include <stddef.h>
#include <stdint.h>
#include <assert.h>
#include <stdlib.h>
 
#include "common/colorspaces_inline_conversions.h"
#include "common/darktable.h"
#include "common/histogram.h"
#include "develop/imageop.h"
 
#define S(V, params) ((params->mul) * ((float)V))
#define P(V, params) (CLAMP((V), 0, (params->bins_count - 1)))
#define PU(V, params) (MIN((V), (params->bins_count - 1)))
#define PS(V, params) (P(S(V, params), params))
 
//------------------------------------------------------------------------------
 
inline static void histogram_helper_cs_RAW_helper_process_pixel_float(
    const dt_dev_histogram_collection_params_t *const histogram_params, const float *pixel, uint32_t *histogram)
{
  const uint32_t i = PS(*pixel, histogram_params);
  histogram[4 * i]++;
}
 
inline static void histogram_helper_cs_RAW(const dt_dev_histogram_collection_params_t *const histogram_params,
                                           const void *pixel, uint32_t *histogram, int j,
                                           const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  const float *input = (float *)pixel + roi->width * j + roi->crop_x;
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, input++)
  {
    histogram_helper_cs_RAW_helper_process_pixel_float(histogram_params, input, histogram);
  }
}
 
//------------------------------------------------------------------------------
 
// WARNING: you must ensure that bins_count is big enough
inline static void histogram_helper_cs_RAW_helper_process_pixel_uint16(
    const dt_dev_histogram_collection_params_t *const histogram_params, const uint16_t *pixel, uint32_t *histogram)
{
  const uint16_t i = PU(*pixel, histogram_params);
  histogram[4 * i]++;
}
 
inline void dt_histogram_helper_cs_RAW_uint16(const dt_dev_histogram_collection_params_t *const histogram_params,
                                              const void *pixel, uint32_t *histogram, int j,
                                              const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  uint16_t *in = (uint16_t *)pixel + roi->width * j + roi->crop_x;
 
  // process pixels
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in++)
    histogram_helper_cs_RAW_helper_process_pixel_uint16(histogram_params, in, histogram);
}
 
//------------------------------------------------------------------------------
 
inline static void __attribute__((__unused__)) histogram_helper_cs_rgb_helper_process_pixel_float(
    const dt_dev_histogram_collection_params_t *const histogram_params, const float *pixel, uint32_t *histogram)
{
  const uint32_t R = PS(pixel[0], histogram_params);
  const uint32_t G = PS(pixel[1], histogram_params);
  const uint32_t B = PS(pixel[2], histogram_params);
  histogram[4 * R]++;
  histogram[4 * G + 1]++;
  histogram[4 * B + 2]++;
}
 
inline static void __attribute__((__unused__)) histogram_helper_cs_rgb_helper_process_pixel_float_compensated(
    const dt_dev_histogram_collection_params_t *const histogram_params, const float *pixel, uint32_t *histogram,
    const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_aligned_pixel_t rgb = { dt_ioppr_compensate_middle_grey(pixel[0], profile_info),
                                   dt_ioppr_compensate_middle_grey(pixel[1], profile_info),
                                   dt_ioppr_compensate_middle_grey(pixel[2], profile_info) };
  const uint32_t R = PS(rgb[0], histogram_params);
  const uint32_t G = PS(rgb[1], histogram_params);
  const uint32_t B = PS(rgb[2], histogram_params);
  histogram[4 * R]++;
  histogram[4 * G + 1]++;
  histogram[4 * B + 2]++;
}
 
inline static void histogram_helper_cs_rgb(const dt_dev_histogram_collection_params_t *const histogram_params,
                                           const void *pixel, uint32_t *histogram, int j,
                                           const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  float *in = (float *)pixel + 4 * (roi->width * j + roi->crop_x);
 
  // process aligned pixels with SSE
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in += 4)
  {
    histogram_helper_cs_rgb_helper_process_pixel_float(histogram_params, in, histogram);
  }
}
 
inline static void histogram_helper_cs_rgb_compensated(const dt_dev_histogram_collection_params_t *const histogram_params,
                                           const void *pixel, uint32_t *histogram, int j,
                                           const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  float *in = (float *)pixel + 4 * (roi->width * j + roi->crop_x);
 
  // process aligned pixels with SSE
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in += 4)
  {
    histogram_helper_cs_rgb_helper_process_pixel_float_compensated(histogram_params, in, histogram, profile_info);
  }
}
 
//------------------------------------------------------------------------------
 
inline static void __attribute__((__unused__)) histogram_helper_cs_Lab_helper_process_pixel_float(
    const dt_dev_histogram_collection_params_t *const histogram_params, const float *pixel, uint32_t *histogram)
{
  const float Lv = pixel[0];
  const float av = pixel[1];
  const float bv = pixel[2];
  const float max = histogram_params->bins_count - 1;
  const uint32_t L = CLAMP(histogram_params->mul / 100.0f * (Lv), 0, max);
  const uint32_t a = CLAMP(histogram_params->mul / 256.0f * (av + 128.0f), 0, max);
  const uint32_t b = CLAMP(histogram_params->mul / 256.0f * (bv + 128.0f), 0, max);
  histogram[4 * L]++;
  histogram[4 * a + 1]++;
  histogram[4 * b + 2]++;
}
 
inline static void histogram_helper_cs_Lab(const dt_dev_histogram_collection_params_t *const histogram_params,
                                           const void *pixel, uint32_t *histogram, int j,
                                           const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  float *in = (float *)pixel + 4 * (roi->width * j + roi->crop_x);
 
  // process aligned pixels with SSE
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in += 4)
  {
    histogram_helper_cs_Lab_helper_process_pixel_float(histogram_params, in, histogram);
  }
}
 
inline static void __attribute__((__unused__)) histogram_helper_cs_Lab_LCh_helper_process_pixel_float(
    const dt_dev_histogram_collection_params_t *const histogram_params, const float *pixel, uint32_t *histogram)
{
  dt_aligned_pixel_t LCh;
  dt_Lab_2_LCH(pixel, LCh);
  const uint32_t L = PS((LCh[0] / 100.f), histogram_params);
  const uint32_t C = PS((LCh[1] / (128.0f * sqrtf(2.0f))), histogram_params);
  const uint32_t h = PS(LCh[2], histogram_params);
  histogram[4 * L]++;
  histogram[4 * C + 1]++;
  histogram[4 * h + 2]++;
}
 
inline static void histogram_helper_cs_Lab_LCh(const dt_dev_histogram_collection_params_t *const histogram_params,
                                               const void *pixel, uint32_t *histogram, int j,
                                               const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  float *in = (float *)pixel + 4 * (roi->width * j + roi->crop_x);
 
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in += 4)
  {
    histogram_helper_cs_Lab_LCh_helper_process_pixel_float(histogram_params, in, histogram);
  }
}
 
inline static void histogram_helper_cs_LCh(const dt_dev_histogram_collection_params_t *const histogram_params,
                                           const void *pixel, uint32_t *histogram, int j,
                                           const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const dt_histogram_roi_t *roi = histogram_params->roi;
  float *in = (float *)pixel + 4 * (roi->width * j + roi->crop_x);
 
  for(int i = 0; i < roi->width - roi->crop_width - roi->crop_x; i++, in += 4)
  {
    const uint32_t L = PS((in[0] / 100.f), histogram_params);
    const uint32_t C = PS((in[1] / (128.0f * sqrtf(2.0f))), histogram_params);
    const uint32_t h = PS(in[2], histogram_params);
    histogram[4 * L]++;
    histogram[4 * C + 1]++;
    histogram[4 * h + 2]++;
  }
}
 
//==============================================================================
 
void dt_histogram_worker(dt_dev_histogram_collection_params_t *const histogram_params,
                         dt_dev_histogram_stats_t *histogram_stats, const void *const pixel,
                         uint32_t **histogram, const dt_worker Worker,
                         const dt_iop_order_iccprofile_info_t *const profile_info)
{
  const int nthreads = omp_get_max_threads();
 
  const size_t bins_total = (size_t)4 * histogram_params->bins_count;
  const size_t buf_size = bins_total * sizeof(uint32_t);
  void *partial_hists = calloc(nthreads, buf_size);
 
  if(histogram_params->mul == 0) histogram_params->mul = (double)(histogram_params->bins_count - 1);
 
  const dt_histogram_roi_t *const roi = histogram_params->roi;
  __OMP_PARALLEL_FOR__(shared(partial_hists) )
  for(int j = roi->crop_y; j < roi->height - roi->crop_height; j++)
  {
    uint32_t *thread_hist = (uint32_t *)partial_hists + bins_total * omp_get_thread_num();
    Worker(histogram_params, pixel, thread_hist, j, profile_info);
  }
 
#ifdef _OPENMP
  *histogram = realloc(*histogram, buf_size);
  memset(*histogram, 0, buf_size);
  uint32_t *hist = *histogram;
 
#pragma omp parallel for default(firstprivate) \
  shared(hist, partial_hists) 
  for(size_t k = 0; k < bins_total; k++)
  {
    for(size_t n = 0; n < nthreads; n++)
    {
      const uint32_t *thread_hist = (uint32_t *)partial_hists + bins_total * n;
      hist[k] += thread_hist[k];
    }
  }
#else
  *histogram = realloc(*histogram, buf_size);
  memmove(*histogram, partial_hists, buf_size);
#endif
  dt_free(partial_hists);
 
  histogram_stats->bins_count = histogram_params->bins_count;
  histogram_stats->pixels = (roi->width - roi->crop_width - roi->crop_x)
                            * (roi->height - roi->crop_height - roi->crop_y);
}
 
//------------------------------------------------------------------------------
 
void dt_histogram_helper(dt_dev_histogram_collection_params_t *histogram_params,
    dt_dev_histogram_stats_t *histogram_stats, const dt_iop_colorspace_type_t cst,
    const dt_iop_colorspace_type_t cst_to, const void *pixel, uint32_t **histogram,
    const int compensate_middle_grey, const dt_iop_order_iccprofile_info_t *const profile_info)
{
  float *converted = NULL;
  if(cst == IOP_CS_LAB && cst_to == IOP_CS_LCH)
  {
    const dt_histogram_roi_t *roi = histogram_params->roi;
    const size_t pixels = (size_t)roi->width * roi->height;
    converted = dt_pixelpipe_cache_alloc_align_float_cache(4 * pixels, 0);
 
    if(!IS_NULL_PTR(converted))
    {
      __OMP_PARALLEL_FOR__()
      for(size_t k = 0; k < pixels; k++)
      {
        const size_t offset = 4 * k;
        dt_Lab_2_LCH((const float *)pixel + offset, converted + offset);
        converted[offset + 3] = ((const float *)pixel)[offset + 3];
      }
    }
  }
 
  switch(cst)
  {
    case IOP_CS_RAW:
      dt_histogram_worker(histogram_params, histogram_stats, pixel, histogram, histogram_helper_cs_RAW, profile_info);
      histogram_stats->ch = 1u;
      break;
 
    case IOP_CS_RGB:
    case IOP_CS_RGB_DISPLAY:
      if(compensate_middle_grey && profile_info)
        dt_histogram_worker(histogram_params, histogram_stats, pixel, histogram, histogram_helper_cs_rgb_compensated, profile_info);
      else
        dt_histogram_worker(histogram_params, histogram_stats, pixel, histogram, histogram_helper_cs_rgb, profile_info);
      histogram_stats->ch = 3u;
      break;
 
    case IOP_CS_LAB:
    default:
      if(cst_to != IOP_CS_LCH)
        dt_histogram_worker(histogram_params, histogram_stats, pixel, histogram, histogram_helper_cs_Lab, profile_info);
      else if(!IS_NULL_PTR(converted))
        dt_histogram_worker(histogram_params, histogram_stats, converted, histogram, histogram_helper_cs_LCh, profile_info);
      else
        dt_histogram_worker(histogram_params, histogram_stats, pixel, histogram, histogram_helper_cs_Lab_LCh, profile_info);
      histogram_stats->ch = 3u;
      break;
  }
 
  dt_pixelpipe_cache_free_align(converted);
}
 
void dt_histogram_max_helper(const dt_dev_histogram_stats_t *const histogram_stats,
                             const dt_iop_colorspace_type_t cst, const dt_iop_colorspace_type_t cst_to,
                             uint32_t **histogram, uint32_t *histogram_max)
{
  if(IS_NULL_PTR(*histogram)) return;
  histogram_max[0] = histogram_max[1] = histogram_max[2] = histogram_max[3] = 0;
  uint32_t *hist = *histogram;
  switch(cst)
  {
    case IOP_CS_RAW:
      for(int k = 0; k < 4 * histogram_stats->bins_count; k += 4)
        histogram_max[0] = histogram_max[0] > hist[k] ? histogram_max[0] : hist[k];
      break;
 
    case IOP_CS_RGB:
    case IOP_CS_RGB_DISPLAY:
      // don't count <= 0 pixels
      for(int k = 4; k < 4 * histogram_stats->bins_count; k += 4)
        histogram_max[0] = histogram_max[0] > hist[k] ? histogram_max[0] : hist[k];
      for(int k = 5; k < 4 * histogram_stats->bins_count; k += 4)
        histogram_max[1] = histogram_max[1] > hist[k] ? histogram_max[1] : hist[k];
      for(int k = 6; k < 4 * histogram_stats->bins_count; k += 4)
        histogram_max[2] = histogram_max[2] > hist[k] ? histogram_max[2] : hist[k];
      for(int k = 7; k < 4 * histogram_stats->bins_count; k += 4)
        histogram_max[3] = histogram_max[3] > hist[k] ? histogram_max[3] : hist[k];
      break;
 
    case IOP_CS_LAB:
    default:
      if(cst_to == IOP_CS_LCH)
      {
        // don't count <= 0 pixels
        for(int k = 4; k < 4 * histogram_stats->bins_count; k += 4)
          histogram_max[0] = histogram_max[0] > hist[k] ? histogram_max[0] : hist[k];
        for(int k = 5; k < 4 * histogram_stats->bins_count; k += 4)
          histogram_max[1] = histogram_max[1] > hist[k] ? histogram_max[1] : hist[k];
        for(int k = 6; k < 4 * histogram_stats->bins_count; k += 4)
          histogram_max[2] = histogram_max[2] > hist[k] ? histogram_max[2] : hist[k];
        for(int k = 7; k < 4 * histogram_stats->bins_count; k += 4)
          histogram_max[3] = histogram_max[3] > hist[k] ? histogram_max[3] : hist[k];
      }
      else
      {
        // don't count <= 0 pixels in L
        for(int k = 4; k < 4 * histogram_stats->bins_count; k += 4)
          histogram_max[0] = histogram_max[0] > hist[k] ? histogram_max[0] : hist[k];
 
        // don't count <= -128 and >= +128 pixels in a and b
        for(int k = 5; k < 4 * (histogram_stats->bins_count - 1); k += 4)
          histogram_max[1] = histogram_max[1] > hist[k] ? histogram_max[1] : hist[k];
        for(int k = 6; k < 4 * (histogram_stats->bins_count - 1); k += 4)
          histogram_max[2] = histogram_max[2] > hist[k] ? histogram_max[2] : hist[k];
      }
      break;
  }
}
 
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