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/* find percent of pixels
*
* Copyright: 1990, N. Dessipris
*
* Author: N. Dessipris
* Written on: 02/08/1990
* Modified on : 29/4/93 K.Martinez for Sys5
* 20/2/95 JC
* - now returns result through parameter
* - ANSIfied a little
* 19/1/07
* - redone with the vips hist operators
* 25/3/10
* - gtkdoc
* 20/9/13
* - wrap as a class
* - more accurate
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>
#include <stdio.h>
#include <string.h>
#include <vips/vips.h>
typedef struct _VipsPercent {
VipsOperation parent_instance;
VipsImage *in;
double percent;
int threshold;
} VipsPercent;
typedef VipsOperationClass VipsPercentClass;
G_DEFINE_TYPE(VipsPercent, vips_percent, VIPS_TYPE_OPERATION);
static int
vips_percent_build(VipsObject *object)
{
VipsPercent *percent = (VipsPercent *) object;
VipsImage **t = (VipsImage **) vips_object_local_array(object, 7);
double threshold;
if (VIPS_OBJECT_CLASS(vips_percent_parent_class)->build(object))
return -1;
if (vips_hist_find(percent->in, &t[0], NULL) ||
vips_hist_cum(t[0], &t[1], NULL) ||
vips_hist_norm(t[1], &t[2], NULL) ||
vips_more_const1(t[2], &t[3],
(percent->percent / 100.0) * t[2]->Xsize, NULL) ||
vips_profile(t[3], &t[5], &t[6], NULL) ||
vips_avg(t[6], &threshold, NULL))
return -1;
g_object_set(object, "threshold", (int) threshold, NULL);
return 0;
}
static void
vips_percent_class_init(VipsPercentClass *class)
{
GObjectClass *gobject_class = G_OBJECT_CLASS(class);
VipsObjectClass *object_class = (VipsObjectClass *) class;
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
object_class->nickname = "percent";
object_class->description = _("find threshold for percent of pixels");
object_class->build = vips_percent_build;
VIPS_ARG_IMAGE(class, "in", 1,
_("Input"),
_("Input image"),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET(VipsPercent, in));
VIPS_ARG_DOUBLE(class, "percent", 2,
_("Percent"),
_("Percent of pixels"),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET(VipsPercent, percent),
0, 100, 50);
VIPS_ARG_INT(class, "threshold", 3,
_("Threshold"),
_("Threshold above which lie percent of pixels"),
VIPS_ARGUMENT_REQUIRED_OUTPUT,
G_STRUCT_OFFSET(VipsPercent, threshold),
0, 65535, 0);
}
static void
vips_percent_init(VipsPercent *percent)
{
}
/**
* vips_percent: (method)
* @in: input image
* @percent: threshold percentage
* @threshold: (out): output threshold value
* @...: `NULL`-terminated list of optional named arguments
*
* [method@Image.percent] returns (through the @threshold parameter) the threshold
* below which there are @percent values of @in. For example:
*
* ```bash
* $ vips percent k2.jpg 90
* 214
* ```
*
* Means that 90% of pixels in `k2.jpg` have a value less than 214.
*
* The function works for uchar and ushort images only. It can be used
* to threshold the scaled result of a filtering operation.
*
* ::: seealso
* [method@Image.hist_find], [method@Image.profile].
*
* Returns: 0 on success, -1 on error
*/
int
vips_percent(VipsImage *in, double percent, int *threshold, ...)
{
va_list ap;
int result;
va_start(ap, threshold);
result = vips_call_split("percent", ap, in, percent, threshold);
va_end(ap);
return result;
}
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