gimp/app/gimphistogram.c

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/* The GIMP -- an image manipulation program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimphistogram module Copyright (C) 1999 Jay Cox <jaycox@earthlink.net>
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "gimphistogramP.h"
#include "gimphistogram.h"
#include "pixel_region.h"
#include "gimpdrawable.h"
#include "channel.h"
#include "gimpimage.h"
#include "gimprc.h"
#include <glib.h>
#include <math.h>
#ifdef ENABLE_MP
#include <pthread.h>
#endif /* ENABLE_MP */
GimpHistogram *
gimp_histogram_new()
{
GimpHistogram *histogram;
histogram = g_new(GimpHistogram, 1);
histogram->values = NULL;
histogram->nchannels = 0;
return histogram;
}
void
gimp_histogram_free (GimpHistogram *histogram)
{
int i;
if (histogram->values)
{
for (i = 0; i < histogram->nchannels; i++)
g_free(histogram->values[i]);
g_free(histogram->values);
}
g_free(histogram);
}
void
gimp_histogram_calculate_sub_region(GimpHistogram *histogram,
PixelRegion *region, PixelRegion *mask)
{
const unsigned char *src, *msrc;
const unsigned char *m, *s;
double **values;
int h, w, max;
#ifdef ENABLE_MP
int slot = 0;
/* find an unused temporary slot to put our results in and lock it */
pthread_mutex_lock(&histogram->mutex);
{
while (histogram->tmp_slots[slot])
slot++;
values = histogram->tmp_values[slot];
histogram->tmp_slots[slot] = 1;
}
pthread_mutex_unlock(&histogram->mutex);
#else /* !ENABLE_MP */
values = histogram->values;
#endif
h = region->h;
w = region->w;
if (mask)
{
double masked;
src = region->data;
msrc = region->data;
while (h--)
{
s = src;
m = msrc;
w = region->w;
switch(region->bytes)
{
case 1:
while (w--)
{
masked = m[0] / 255.0;
values[0][s[0]] += masked;
s += 1;
m += 1;
} break;
case 2:
while (w--)
{
masked = m[0] / 255.0;
values[0][s[0]] += masked;
values[1][s[1]] += masked;
s += 2;
m += 1;
} break;
case 3: /* calculate seperate value values */
while (w--)
{
masked = m[0] / 255.0;
values[1][s[0]] += masked;
values[2][s[1]] += masked;
values[3][s[2]] += masked;
max = (s[0] > s[1]) ? s[0] : s[1];
if (s[2] > max)
values[0][s[2]] += masked;
else
values[0][max] += masked;
s += 3;
m += 1;
} break;
case 4: /* calculate seperate value values */
while (w--)
{
masked = m[0] / 255.0;
values[1][s[0]] += masked;
values[2][s[1]] += masked;
values[3][s[2]] += masked;
values[4][s[3]] += masked;
max = (s[0] > s[1]) ? s[0] : s[1];
if (s[2] > max)
values[0][s[2]] += masked;
else
values[0][max] += masked;
s += 3;
m += 1;
} break;
}
src += region->rowstride;
msrc += mask->rowstride;
}
}
else /* no mask */
{
src = region->data;
while (h--)
{
s = src;
w = region->w;
switch(region->bytes)
{
case 1:
while (w--)
{
values[0][s[0]] += 1.0;
s += 1;
} break;
case 2:
while (w--)
{
values[0][s[0]] += 1.0;
values[1][s[1]] += 1.0;
s += 2;
} break;
case 3: /* calculate seperate value values */
while (w--)
{
values[1][s[0]] += 1.0;
values[2][s[1]] += 1.0;
values[3][s[2]] += 1.0;
max = (s[0] > s[1]) ? s[0] : s[1];
if (s[2] > max)
values[0][s[2]] += 1.0;
else
values[0][max] += 1.0;
s += 3;
} break;
case 4: /* calculate seperate value values */
while (w--)
{
values[1][s[0]] += 1.0;
values[2][s[1]] += 1.0;
values[3][s[2]] += 1.0;
values[4][s[3]] += 1.0;
max = (s[0] > s[1]) ? s[0] : s[1];
if (s[2] > max)
values[0][s[2]] += 1.0;
else
values[0][max] += 1.0;
s += 3;
} break;
}
src += region->rowstride;
}
}
#ifdef ENABLE_MP
/* unlock this slot */
/* we shouldn't have to use mutex locks here */
pthread_mutex_lock(&histogram->mutex);
histogram->tmp_slots[slot] = 0;
pthread_mutex_unlock(&histogram->mutex);
#endif
}
static void gimp_histogram_alloc(GimpHistogram *histogram, int bytes)
{
int i;
if (bytes + 1 != histogram->nchannels)
{
if (histogram->values)
{
for (i = 0; i < histogram->nchannels; i++)
g_free(histogram->values[i]);
g_free(histogram->values);
}
histogram->nchannels = bytes + 1;
histogram->values = g_new(double *, histogram->nchannels);
for (i = 0; i < histogram->nchannels; i++)
histogram->values[i] = g_new(double, 256);
}
}
void
gimp_histogram_calculate (GimpHistogram *histogram, PixelRegion *region,
PixelRegion *mask)
{
int i, j;
#ifdef ENABLE_MP
int k;
#endif
gimp_histogram_alloc(histogram, region->bytes);
#ifdef ENABLE_MP
pthread_mutex_init(&histogram->mutex, NULL);
histogram->tmp_slots = g_new(char, num_processors);
histogram->tmp_values = g_new(double **, num_processors);
for (i = 0; i < num_processors; i++)
{
histogram->tmp_values[i] = g_new(double *, histogram->nchannels);
histogram->tmp_slots[i] = 0;
for (j = 0; j < histogram->nchannels; j++)
{
histogram->tmp_values[i][j] = g_new(double, 256);
for (k = 0; k < 256; k++)
histogram->tmp_values[i][j][k] = 0.0;
}
}
#endif
for (i = 0; i < histogram->nchannels; i++)
for (j = 0; j < 256; j++)
histogram->values[i][j] = 0.0;
pixel_regions_process_parallel((p_func)gimp_histogram_calculate_sub_region,
histogram, 2, region, mask);
#ifdef ENABLE_MP
/* add up all the tmp buffers and free their memmory */
for (i = 0; i < num_processors; i++)
{
for (j = 0; j < histogram->nchannels; j++)
{
for (k = 0; k < 256; k++)
histogram->values[j][k] += histogram->tmp_values[i][j][k];
g_free (histogram->tmp_values[i][j]);
}
g_free(histogram->tmp_values[i]);
}
g_free(histogram->tmp_values);
g_free(histogram->tmp_slots);
#endif
}
void
gimp_histogram_calculate_drawable(GimpHistogram *histogram,
GimpDrawable *drawable)
{
PixelRegion region;
PixelRegion mask;
int x1, y1, x2, y2;
int off_x, off_y;
int no_mask;
no_mask = (drawable_mask_bounds (drawable, &x1, &y1, &x2, &y2) == FALSE);
pixel_region_init (&region, gimp_drawable_data (drawable), x1, y1,
(x2 - x1), (y2 - y1), FALSE);
if (!no_mask)
{
Channel *sel_mask;
GimpImage *gimage;
gimage = gimp_drawable_gimage(drawable);
sel_mask = gimp_image_get_mask (gimage);
drawable_offsets (drawable, &off_x, &off_y);
pixel_region_init (&mask, gimp_drawable_data (GIMP_DRAWABLE (sel_mask)),
x1 + off_x, y1 + off_y, (x2 - x1), (y2 - y1), FALSE);
gimp_histogram_calculate (histogram, &region, &mask);
}
else
gimp_histogram_calculate (histogram, &region, NULL);
}
double
gimp_histogram_get_maximum (GimpHistogram *histogram, int channel)
{
double max = 0.0;
int x;
for (x = 0; x < 256; x++)
if (histogram->values[channel][x] > max)
max = histogram->values[channel][x];
return max;
}
double
gimp_histogram_get_value (GimpHistogram *histogram, int channel, int bin)
{
if (channel < histogram->nchannels && bin >= 0 && bin < 256)
return histogram->values[channel][bin];
return 0.0;
}
double
gimp_histogram_get_channel (GimpHistogram *histogram, int channel, int bin)
{
if (histogram->nchannels > 3)
return gimp_histogram_get_value(histogram, channel + 1, bin);
else
return gimp_histogram_get_value(histogram, channel , bin);
}
int
gimp_histogram_nchannels (GimpHistogram *histogram)
{
return histogram->nchannels - 1;
}
double
gimp_histogram_get_count (GimpHistogram *histogram, int start, int end)
{
int i;
double count = 0.0;
for (i = start; i <= end; i++)
count += histogram->values[0][i];
return count;
}
double
gimp_histogram_get_mean (GimpHistogram *histogram, int channel,
int start, int end)
{
int i;
double mean = 0.0;
double count;
for (i = start; i <= end; i++)
mean += i * histogram->values[channel][i];
count = gimp_histogram_get_count(histogram, start, end);
if (count > 0.0)
return mean / count;
return mean;
}
int
gimp_histogram_get_median (GimpHistogram *histogram, int channel, int start, int end)
{
int i;
double sum = 0.0;
double count;
count = gimp_histogram_get_count(histogram, start, end);
for (i = start; i <= end; i++)
{
sum += i * histogram->values[channel][i];
if (sum * 2 > count)
return i;
}
return -1;
}
double
gimp_histogram_get_std_dev (GimpHistogram *histogram, int channel,
int start, int end)
{
int i;
double dev = 0.0;
double count;
double mean;
mean = gimp_histogram_get_mean(histogram, channel, start, end);
count = gimp_histogram_get_count(histogram, start, end);
if (count == 0.0)
count = 1.0;
for (i = start; i <= end; i++)
dev += gimp_histogram_get_value(histogram, channel, i) *
(i - mean) * (i - mean);
return sqrt (dev / count);
}