/* test for monotonicity

 *

 * Author: John Cupitt

 * Written on: 18/7/1995

 * 17/9/96 JC

 *  - restrictions on Ps, Pm, Ph relaxed

 *  - restrictions on S, M, H relaxed

 * 25/7/01 JC

 *  - patched for im_extract_band() change

 * 11/7/04

 *  - generalised to im_tone_build_range() ... so you can use it for any

 *    image, not just LabS

 * 26/3/10

 *  - cleanups

 *  - gtkdoc

 * 20/9/13

 *  - redone as a class

 */

/*

  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 <vips/vips.h>

typedef struct _VipsHistIsmonotonic {

  VipsOperation parent_instance;

  VipsImage *in;

  gboolean monotonic;

} VipsHistIsmonotonic;

typedef VipsOperationClass VipsHistIsmonotonicClass;

G_DEFINE_TYPE(VipsHistIsmonotonic, vips_hist_ismonotonic,

  VIPS_TYPE_OPERATION);

static int

vips_hist_ismonotonic_build(VipsObject *object)

{

  VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(object);

  VipsHistIsmonotonic *ismonotonic = (VipsHistIsmonotonic *) object;

  VipsImage **t = (VipsImage **) vips_object_local_array(object, 4);

  double m;

  if (VIPS_OBJECT_CLASS(vips_hist_ismonotonic_parent_class)->build(object))

    return -1;

  if (vips_check_hist(class->nickname, ismonotonic->in))

    return -1;

  if (ismonotonic->in->Xsize == 1)

    t[0] = vips_image_new_matrixv(1, 2, -1.0, 1.0);

  else

    t[0] = vips_image_new_matrixv(2, 1, -1.0, 1.0);

  vips_image_set_double(t[0], "offset", 128);

  /* We want >=128 everywhere, ie. no -ve transitions.

   */

  if (vips_conv(ismonotonic->in, &t[1], t[0],

      "precision", VIPS_PRECISION_INTEGER,

      NULL) ||

    vips_moreeq_const1(t[1], &t[2], 128, NULL) ||

    vips_min(t[2], &m, NULL))

    return -1;

  g_object_set(ismonotonic, "monotonic", (int) m == 255, NULL);

  return 0;

}

static void

vips_hist_ismonotonic_class_init(VipsHistIsmonotonicClass *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 = "hist_ismonotonic";

  object_class->description = _("test for monotonicity");

  object_class->build = vips_hist_ismonotonic_build;

  VIPS_ARG_IMAGE(class, "in", 1,

    _("Input"),

    _("Input histogram image"),

    VIPS_ARGUMENT_REQUIRED_INPUT,

    G_STRUCT_OFFSET(VipsHistIsmonotonic, in));

  VIPS_ARG_BOOL(class, "monotonic", 2,

    _("Monotonic"),

    _("true if in is monotonic"),

    VIPS_ARGUMENT_REQUIRED_OUTPUT,

    G_STRUCT_OFFSET(VipsHistIsmonotonic, monotonic),

    FALSE);

}

static void

vips_hist_ismonotonic_init(VipsHistIsmonotonic *ismonotonic)

{

}

/**

 * vips_hist_ismonotonic: (method)

 * @in: lookup-table to test

 * @out: (out): set non-zero if @in is monotonic

 * @...: %NULL-terminated list of optional named arguments

 *

 * Test @in for monotonicity. @out is set non-zero if @in is monotonic.

 *

 * Returns: 0 on success, -1 on error

 */

int

vips_hist_ismonotonic(VipsImage *in, gboolean *out, ...)

{

  va_list ap;

  int result;

  va_start(ap, out);

  result = vips_call_split("hist_ismonotonic", ap, in, out);

  va_end(ap);

  return result;

}