[gimp/gimp-2-10] app, libgimpbase: add GIMP_SELECT_CRITERION_LINE_ART selection type.
- From: Jehan <jehanp src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gimp/gimp-2-10] app, libgimpbase: add GIMP_SELECT_CRITERION_LINE_ART selection type.
- Date: Wed, 19 Dec 2018 15:41:48 +0000 (UTC)
commit bde56bdfdcdddad37c2812876ab253310461b061
Author: Jehan <jehan girinstud io>
Date: Wed Oct 10 20:28:47 2018 +0200
app, libgimpbase: add GIMP_SELECT_CRITERION_LINE_ART selection type.
This commit implements part of the research paper "A Fast and Efficient
Semi-guided Algorithm for Flat Coloring Line-arts" from the GREYC (the
people from G'Mic). It is meant to select regions from drawn sketchs in
a "smart" way, in particular it tries to close non-perfectly closed
regions, which is a common headache for digital painters and colorists.
The implementation is not finished as it needs some watersheding as well
so that the selected area does not leave "holes" near stroke borders.
The research paper proposes a new watersheding algorithm, but I may not
have to implement it, as it is more focused on automatic colorization
with prepared spots (instead of bucket fill-type interaction).
This will be used in particular with the fuzzy select and bucket fill
tools.
Note that this first version is a bit slow once we get to big images,
but I hope to be able to optimize this.
Also no options from the algorithm are made available in the GUI yet.
(cherry picked from commit 8ed12b1b9830f8c1956b408f994be6c81bd8f21a)
app/core/Makefile.am | 2 +
app/core/gimplineart.c | 2250 +++++++++++++++++++++++++++++
app/core/gimplineart.h | 43 +
app/core/gimppickable-contiguous-region.c | 66 +-
libgimpbase/gimpbaseenums.c | 2 +
libgimpbase/gimpbaseenums.h | 2 +
libgimpwidgets/gimppropwidgets.c | 5 +-
pdb/enums.pl | 6 +-
8 files changed, 2371 insertions(+), 5 deletions(-)
---
diff --git a/app/core/Makefile.am b/app/core/Makefile.am
index 48382f4747..626cafd20a 100644
--- a/app/core/Makefile.am
+++ b/app/core/Makefile.am
@@ -355,6 +355,8 @@ libappcore_a_sources = \
gimplayerstack.h \
gimplayerundo.c \
gimplayerundo.h \
+ gimplineart.c \
+ gimplineart.h \
gimplist.c \
gimplist.h \
gimpmaskundo.c \
diff --git a/app/core/gimplineart.c b/app/core/gimplineart.c
new file mode 100644
index 0000000000..1b29abe7ee
--- /dev/null
+++ b/app/core/gimplineart.c
@@ -0,0 +1,2250 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * Copyright (C) 2017 Sébastien Fourey & David Tchumperlé
+ * Copyright (C) 2018 Jehan
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#define GEGL_ITERATOR2_API
+#include <gegl.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "core-types.h"
+
+#include "gimplineart.h"
+
+static int DeltaX[4] = {+1, -1, 0, 0};
+static int DeltaY[4] = {0, 0, +1, -1};
+
+static const GimpVector2 Direction2Normal[4] =
+{
+ { 1.0f, 0.0f },
+ { -1.0f, 0.0f },
+ { 0.0f, 1.0f },
+ { 0.0f, -1.0f }
+};
+
+typedef enum _Direction
+{
+ XPlusDirection = 0,
+ XMinusDirection = 1,
+ YPlusDirection = 2,
+ YMinusDirection = 3
+} Direction;
+
+typedef GimpVector2 Pixel;
+
+typedef struct _SplineCandidate
+{
+ Pixel p1;
+ Pixel p2;
+ float quality;
+} SplineCandidate;
+
+typedef struct _Edgel
+{
+ gint x, y;
+ Direction direction;
+
+ gfloat x_normal;
+ gfloat y_normal;
+ gfloat curvature;
+ guint next, previous;
+} Edgel;
+
+static GeglBuffer * gimp_lineart_get_labels (GeglBuffer *line_art,
+ gboolean is_high_connectivity);
+static void gimp_lineart_erode (GeglBuffer *buffer,
+ gint s);
+static void gimp_lineart_denoise (GeglBuffer *buffer,
+ int size);
+static void gimp_lineart_compute_normals_curvatures (GeglBuffer *mask,
+ gfloat ***normals,
+ gfloat **curvatures,
+ int
normal_estimate_mask_size);
+static GArray * gimp_lineart_curvature_extremums (gfloat **curvatures,
+ gint curvatures_width,
+ gint curvatures_height);
+static gint gimp_spline_candidate_cmp (const SplineCandidate *a,
+ const SplineCandidate *b,
+ gpointer user_data);
+static GList * gimp_lineart_find_spline_candidates (GArray *max_positions,
+ gfloat ***normals,
+ gint distance_threshold,
+ gfloat max_angle_deg);
+
+static GArray * gimp_lineart_discrete_spline (Pixel p0,
+ GimpVector2 n0,
+ Pixel p1,
+ GimpVector2 n1);
+
+static gint gimp_number_of_transitions (GArray *pixels,
+ GeglBuffer *buffer,
+ gboolean border_value);
+static gboolean gimp_lineart_curve_creates_region (GeglBuffer *mask,
+ GArray *pixels,
+ int lower_size_limit,
+ int upper_size_limit);
+static GArray * gimp_lineart_line_segment_until_hit (const GeglBuffer *buffer,
+ Pixel start,
+ GimpVector2 direction,
+ int size);
+static gfloat gimp_lineart_estimate_stroke_width (GeglBuffer *mask);
+
+/* Some callback-type functions. */
+
+static guint visited_hash_fun (Pixel *key);
+static gboolean visited_equal_fun (Pixel *e1,
+ Pixel *e2);
+static gint float_compare (gconstpointer p1,
+ gconstpointer p2);
+
+static inline gboolean border_in_direction (GeglBuffer *mask,
+ Pixel p,
+ int direction);
+static inline GimpVector2 pair2normal (Pixel p,
+ gfloat ***normals);
+
+/* Edgel */
+
+static Edgel * gimp_edgel_new (int x,
+ int y,
+ Direction direction);
+static void gimp_edgel_init (Edgel *edgel);
+static void gimp_edgel_clear (Edgel **edgel);
+static int gimp_edgel_cmp (const Edgel *e1,
+ const Edgel *e2);
+static guint edgel2index_hash_fun (Edgel *key);
+static gboolean edgel2index_equal_fun (Edgel *e1,
+ Edgel *e2);
+
+static glong gimp_edgel_track_mark (GeglBuffer *mask,
+ Edgel edgel,
+ long size_limit);
+static glong gimp_edgel_region_area (const GeglBuffer *mask,
+ Edgel starting_edgel);
+
+/* Edgel set */
+
+static GArray * gimp_edgelset_new (GeglBuffer *buffer);
+static void gimp_edgelset_add (GArray *set,
+ int x,
+ int y,
+ Direction direction,
+ GHashTable *edgel2index);
+static void gimp_edgelset_init_normals (GArray *set);
+static void gimp_edgelset_smooth_normals (GArray *set,
+ int mask_size);
+static void gimp_edgelset_compute_curvature (GArray *set);
+
+static void gimp_edgelset_build_graph (GArray *set,
+ GeglBuffer *buffer,
+ GHashTable *edgel2index);
+static void gimp_edgelset_next8 (const GeglBuffer *buffer,
+ Edgel *it,
+ Edgel *n);
+
+/* Public functions */
+
+/**
+ * gimp_lineart_close:
+ * @line_art: the input #GeglBuffer
+ * @select_transparent: whether we binarize the alpha channel or the
+ * luminosity.
+ * @stroke_threshold: [0-1] threshold value for detecting stroke pixels
+ * (higher values will detect more stroke pixels).
+ * @erosion:
+ * @minimal_lineart_area:
+ * @normal_estimate_mask_size:
+ * @end_point_rate: [0-1] range value.
+ * @spline_max_length:
+ * @spline_max_angle:
+ * @end_point_connectivity:
+ * @spline_roundness:
+ * @allow_self_intersections:
+ * @created_regions_significant_area:
+ * @created_regions_minimum_area:
+ * @small_segments_from_spline_sources:
+ * @segments_max_length:
+ *
+ * Creates a binarized version of the strokes of @line_art, detected either
+ * with luminosity (light means background) or alpha values depending on
+ * @select_transparent. This binary version of the strokes will have closed
+ * regions allowing adequate selection of "nearly closed regions".
+ * This algorithm is meant for digital painting (and in particular on the
+ * sketch-only step), and therefore will likely produce unexpected results on
+ * other types of input.
+ *
+ * The algorithm is the first step from the research paper "A Fast and
+ * Efficient Semi-guided Algorithm for Flat Coloring Line-arts", by Sébastian
+ * Fourey, David Tschumperlé, David Revoy.
+ *
+ * Returns: a new #GeglBuffer of format "Y u8" representing the
+ * binarized @line_art. A value of
+ */
+GeglBuffer *
+gimp_lineart_close (GeglBuffer *line_art,
+ gboolean select_transparent,
+ gfloat stroke_threshold,
+ gint erosion,
+ gint minimal_lineart_area,
+ gint normal_estimate_mask_size,
+ gfloat end_point_rate,
+ gint spline_max_length,
+ gfloat spline_max_angle,
+ gint end_point_connectivity,
+ gfloat spline_roundness,
+ gboolean allow_self_intersections,
+ gint created_regions_significant_area,
+ gint created_regions_minimum_area,
+ gboolean small_segments_from_spline_sources,
+ gint segments_max_length)
+{
+ const Babl *gray_format;
+ gfloat ***normals;
+ gfloat **curvatures;
+ GeglBufferIterator *gi;
+ GeglBuffer *closed;
+ GeglBuffer *strokes;
+ GHashTable *visited;
+ GArray *keypoints;
+ Pixel *point;
+ GList *candidates;
+ SplineCandidate *candidate;
+ guchar max_value = 0;
+ gfloat threshold;
+ gint width = gegl_buffer_get_width (line_art);
+ gint height = gegl_buffer_get_height (line_art);
+ gint i;
+
+ normals = g_new (gfloat **, width);
+ curvatures = g_new (gfloat *, width);
+ for (i = 0; i < width; i++)
+ {
+ gint j;
+
+ normals[i] = g_new (gfloat *, height);
+ for (j = 0; j < height; j++)
+ {
+ normals[i][j] = g_new (gfloat, 2);
+ memset (normals[i][j], 0, sizeof (gfloat) * 2);
+ }
+ curvatures[i] = g_new (gfloat, height);
+ memset (curvatures[i], 0, sizeof (gfloat) * height);
+ }
+
+ if (select_transparent)
+ /* Keep alpha channel as gray levels */
+ gray_format = babl_format ("A u8");
+ else
+ /* Keep luminance */
+ gray_format = babl_format ("Y' u8");
+
+ /* Transform the line art from any format to gray. */
+ strokes = gegl_buffer_new (gegl_buffer_get_extent (line_art),
+ gray_format);
+ gegl_buffer_copy (line_art, NULL, GEGL_ABYSS_NONE, strokes, NULL);
+ gegl_buffer_set_format (strokes, babl_format ("Y' u8"));
+
+ if (! select_transparent)
+ {
+ /* Compute the biggest value */
+ gi = gegl_buffer_iterator_new (strokes, NULL, 0, NULL,
+ GEGL_ACCESS_READ, GEGL_ABYSS_NONE, 1);
+ while (gegl_buffer_iterator_next (gi))
+ {
+ guchar *data = (guchar*) gi->items[0].data;
+ gint k;
+
+ for (k = 0; k < gi->length; k++)
+ {
+ if (*data > max_value)
+ max_value = *data;
+ data++;
+ }
+ }
+ }
+
+ /* Make the image binary: 1 is stroke, 0 background */
+ gi = gegl_buffer_iterator_new (strokes, NULL, 0, NULL,
+ GEGL_ACCESS_READWRITE, GEGL_ABYSS_NONE, 1);
+ while (gegl_buffer_iterator_next (gi))
+ {
+ guchar *data = (guchar*) gi->items[0].data;
+ gint k;
+
+ for (k = 0; k < gi->length; k++)
+ {
+ if (! select_transparent)
+ /* Negate the value. */
+ *data = max_value - *data;
+ /* Apply a threshold. */
+ if (*data > (guchar) (255.0f * (1.0f - stroke_threshold)))
+ *data = 1;
+ else
+ *data = 0;
+ data++;
+ }
+ }
+
+ if (erosion > 0)
+ {
+ gimp_lineart_erode (strokes, erosion);
+ }
+ else if (erosion == -1)
+ {
+ const gfloat stroke_width = gimp_lineart_estimate_stroke_width (strokes);
+ const gint erode_size = (gint) roundf (stroke_width / 5);
+
+ if (erode_size)
+ gimp_lineart_erode (strokes, 2 * erode_size);
+ }
+
+ /* Denoise (remove small connected components) */
+ gimp_lineart_denoise (strokes, minimal_lineart_area);
+
+ /* Estimate normals & curvature */
+ gimp_lineart_compute_normals_curvatures (strokes, normals, curvatures,
+ normal_estimate_mask_size);
+
+ threshold = 1.0f - end_point_rate;
+ for (i = 0; i < width; i++)
+ {
+ gint j;
+ for (j = 0; j < height; j++)
+ {
+ gfloat v = curvatures[i][j];
+
+ curvatures[i][j] = v >= threshold ? v - threshold :
+ (v <= -threshold ? v + threshold : 0.0f);
+ }
+ }
+
+ keypoints = gimp_lineart_curvature_extremums (curvatures, width, height);
+ candidates = gimp_lineart_find_spline_candidates (keypoints, normals,
+ spline_max_length,
+ spline_max_angle);
+ closed = gegl_buffer_dup (strokes);
+
+ /* Draw splines */
+ visited = g_hash_table_new_full ((GHashFunc) visited_hash_fun,
+ (GEqualFunc) visited_equal_fun,
+ (GDestroyNotify) g_free, NULL);
+ while (candidates)
+ {
+ Pixel *p1 = g_new (Pixel, 1);
+ Pixel *p2 = g_new (Pixel, 1);
+ gboolean inserted = FALSE;
+
+ candidate = (SplineCandidate *) candidates->data;
+ p1->x = candidate->p1.x;
+ p1->y = candidate->p1.y;
+ p2->x = candidate->p2.x;
+ p2->y = candidate->p2.y;
+
+ g_free (candidate);
+ candidates = g_list_delete_link (candidates, candidates);
+
+ if ((! g_hash_table_contains (visited, p1) ||
+ GPOINTER_TO_INT (g_hash_table_lookup (visited, p1)) < end_point_connectivity) &&
+ (! g_hash_table_contains (visited, p2) ||
+ GPOINTER_TO_INT (g_hash_table_lookup (visited, p2)) < end_point_connectivity))
+ {
+ GArray *discrete_curve;
+ GimpVector2 vect1 = pair2normal (*p1, normals);
+ GimpVector2 vect2 = pair2normal (*p2, normals);
+ gfloat distance = gimp_vector2_length_val (gimp_vector2_sub_val (*p1, *p2));
+ gint transitions;
+
+ gimp_vector2_mul (&vect1, distance);
+ gimp_vector2_mul (&vect1, spline_roundness);
+ gimp_vector2_mul (&vect2, distance);
+ gimp_vector2_mul (&vect2, spline_roundness);
+
+ discrete_curve = gimp_lineart_discrete_spline (*p1, vect1, *p2, vect2);
+
+ transitions = allow_self_intersections ?
+ gimp_number_of_transitions (discrete_curve, strokes, FALSE) :
+ gimp_number_of_transitions (discrete_curve, closed, FALSE);
+
+ if (transitions == 2 &&
+ ! gimp_lineart_curve_creates_region (closed, discrete_curve,
+ created_regions_significant_area,
+ created_regions_minimum_area - 1))
+ {
+ for (i = 0; i < discrete_curve->len; i++)
+ {
+ Pixel p = g_array_index (discrete_curve, Pixel, i);
+
+ if (p.x >= 0 && p.x < gegl_buffer_get_width (closed) &&
+ p.y >= 0 && p.y < gegl_buffer_get_height (closed))
+ {
+ guchar val = 1;
+
+ gegl_buffer_set (closed, GEGL_RECTANGLE ((gint) p.x, (gint) p.y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+ g_hash_table_replace (visited, p1,
+ GINT_TO_POINTER (GPOINTER_TO_INT (g_hash_table_lookup (visited, p1)) +
1));
+ g_hash_table_replace (visited, p2,
+ GINT_TO_POINTER (GPOINTER_TO_INT (g_hash_table_lookup (visited, p2)) +
1));
+ inserted = TRUE;
+ }
+ g_array_free (discrete_curve, TRUE);
+ }
+ if (! inserted)
+ {
+ g_free (p1);
+ g_free (p2);
+ }
+ }
+
+ /* Draw straight line segments */
+ point = (Pixel *) keypoints->data;
+ for (i = 0; i < keypoints->len; i++)
+ {
+ Pixel *p = g_new (Pixel, 1);
+ gboolean inserted = FALSE;
+
+ *p = *point;
+
+ if (! g_hash_table_contains (visited, p) ||
+ (small_segments_from_spline_sources &&
+ GPOINTER_TO_INT (g_hash_table_lookup (visited, p)) < end_point_connectivity))
+ {
+ GArray *segment = gimp_lineart_line_segment_until_hit (closed, *point,
+ pair2normal (*point, normals),
+ segments_max_length);
+
+ if (segment->len &&
+ ! gimp_lineart_curve_creates_region (closed, segment,
+ created_regions_significant_area,
+ created_regions_minimum_area - 1))
+ {
+ gint j;
+
+ for (j = 0; j < segment->len; j++)
+ {
+ Pixel p2 = g_array_index (segment, Pixel, j);
+ guchar val = 1;
+
+ gegl_buffer_set (closed, GEGL_RECTANGLE ((gint) p2.x, (gint) p2.y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ g_hash_table_replace (visited, p,
+ GINT_TO_POINTER (GPOINTER_TO_INT (g_hash_table_lookup (visited, p)) +
1));
+ inserted = TRUE;
+ }
+ g_array_free (segment, TRUE);
+ }
+ if (! inserted)
+ g_free (p);
+ point++;
+ }
+
+ g_array_free (keypoints, TRUE);
+ g_object_unref (strokes);
+ g_free (normals);
+ g_free (curvatures);
+ g_list_free_full (candidates, g_free);
+
+ return closed;
+}
+
+/* Private functions */
+
+static GeglBuffer *
+gimp_lineart_get_labels (GeglBuffer *line_art,
+ gboolean is_high_connectivity)
+{
+ /*
+ * Converted from CImg.get_label() code, with tolerance = 0 (used to
+ * determine if two neighboring pixels belong to the same region).
+ * The algorithm of connected components computation has been primarily done
+ * by A. Meijster, according to the publication: 'W.H. Hesselink, A.
+ * Meijster, C. Bron, "Concurrent Determination of Connected Components.",
+ * In: Science of Computer Programming 41 (2001), pp. 173--194'.
+ * The submitted code has then been modified to fit CImg first, then GIMP.
+ */
+ guint32 *data;
+ gint width = gegl_buffer_get_width (line_art);
+ gint height = gegl_buffer_get_height (line_art);
+ guint32 counter = 0;
+ guint32 p = 0;
+
+ /* Create neighborhood tables. */
+ int dx[4], dy[4];
+
+ dx[0] = 1; dy[0] = 0;
+ dx[1] = 0; dy[1] = 1;
+ if (is_high_connectivity)
+ {
+ dx[2] = 1; dy[2] = 1;
+ dx[3] = 1; dy[3] = -1;
+ }
+
+ data = g_new (guint32,
+ babl_format_get_bytes_per_pixel (babl_format_n (babl_type ("u32"), 1)) * width * height);
+
+ /* Init label numbers. */
+ for (guint32 i = 0; i < width * height; i++)
+ data[i] = i;
+
+ /* For each neighbour-direction, label. */
+ for (unsigned int n = 0; n < (is_high_connectivity ? 4 : 2); ++n)
+ {
+ const int _dx = dx[n];
+ const int _dy = dy[n];
+
+ const int x1 = width - _dx;
+ const int y0 = (_dy < 0) ? -_dy : 0;
+ const int y1 = (_dy < 0) ? height : height - _dy;
+ const long offset = _dy * width + _dx;
+
+ for (long y = y0, ny = y0 + _dy, py = y0 * width; y < y1; ++y, ++ny, py += width)
+ {
+ for (long x = 0, nx = _dx, p = py; x < x1; ++x, ++nx, ++p)
+ {
+ guint32 pixel;
+ guint32 neighbour_pixel;
+
+ gegl_buffer_sample (line_art, x, y, NULL, &pixel,
+ babl_format ("Y u32"), GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ gegl_buffer_sample (line_art, nx, ny, NULL, &neighbour_pixel,
+ babl_format ("Y u32"), GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (pixel == neighbour_pixel)
+ {
+ const guint32 q = p + offset;
+ guint32 i, j;
+
+ for (i = MAX (p, q), j = MIN (p, q); i != j && data[i] != i; )
+ {
+ i = (guint32) data[i];
+ if (i < j)
+ {
+ /* Swap i and j. */
+ guint32 temp = i;
+ i = j;
+ j = temp;
+ }
+ }
+ if (i != j)
+ data[i] = j;
+ for (guint32 _p = (guint32) p; _p != j; )
+ {
+ const guint32 h = (guint32) data[_p];
+
+ data[_p] = (guint32) j;
+ _p = h;
+ }
+ for (guint32 _q = (guint32) q; _q != j; )
+ {
+ const guint32 h = (guint32) data[_q];
+
+ data[_q] = (guint32) j;
+ _q = h;
+ }
+ }
+ }
+ }
+ }
+
+ /* Resolve equivalences. */
+ p = 0;
+ for (guint32 i = 0; i < width*height; i++)
+ {
+ data[i] = data[i] == p ? counter++ : data[data[i]];
+ p++;
+ }
+
+ return gegl_buffer_linear_new_from_data (data,
+ babl_format_n (babl_type ("u32"), 1),
+ gegl_buffer_get_extent (line_art), 0,
+ g_free, NULL);
+}
+
+static void
+gimp_lineart_erode (GeglBuffer *buffer,
+ gint s)
+{
+ const Babl *format;
+ gint width;
+ gint height;
+
+ if (s <= 1)
+ return;
+
+ format = gegl_buffer_get_format (buffer);
+ width = gegl_buffer_get_width (buffer);
+ height = gegl_buffer_get_height (buffer);
+
+ if (width > 1)
+ {
+ /* Erosion along X-axis. */
+ GeglBuffer *buf;
+ const int _s2 = s / 2 + 1;
+ const int _s1 = s - _s2;
+ const int s1 = _s1 > width ? width : _s1;
+ const int s2 = _s2 > width ? width : _s2;
+
+ buf = gegl_buffer_new (GEGL_RECTANGLE (0, 0, width, 1), format);
+
+ for (int y = 0; y < height; ++y)
+ {
+ guchar cur;
+ gint xs = 0;
+ gint xd = 0;
+ gboolean is_first = TRUE;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &cur, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ xs++;
+ for (int p = s2 - 1; p > 0 && xs < width; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ xs++;
+ if (val <= cur)
+ {
+ cur = val;
+ is_first = FALSE;
+ }
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (xd, 0, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ xd++;
+
+ if (xs >= width - 1)
+ {
+ guchar se;
+
+ gegl_buffer_sample (buffer, width - 1, y, NULL, &se, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ cur = MIN (cur, se);
+ for (int x = 0; x < width; ++x)
+ {
+ gegl_buffer_set (buffer, GEGL_RECTANGLE (x, y, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+ else
+ {
+ for (int p = s1; p > 0 && xd < width; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (xs < width - 1)
+ xs++;
+ if (val <= cur)
+ {
+ cur = val;
+ is_first = FALSE;
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (xd, 0, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ xd++;
+ }
+ for (int p = width - s - 1; p > 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ xs++;
+ if (is_first)
+ {
+ guchar nval;
+ gint nxs = xs - 1;
+
+ cur = val;
+ for (int q = s - 2; q > 0; --q)
+ {
+ nxs--;
+ gegl_buffer_sample (buffer, nxs, y, NULL, &nval, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+
+ if (nval < cur)
+ cur = nval;
+ }
+ nxs--;
+
+ gegl_buffer_sample (buffer, nxs, y, NULL, &nval, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+
+ if (nval < cur)
+ {
+ cur = nval;
+ is_first = TRUE;
+ }
+ else
+ is_first = FALSE;
+ }
+ else
+ {
+ if (val <= cur)
+ cur = val;
+ else
+ {
+ guchar tmp;
+ gegl_buffer_sample (buffer, xs - s, y, NULL, &tmp, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (cur == tmp)
+ is_first = TRUE;
+ }
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (xd, 0, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ xd++;
+ }
+ xd = width - 1;
+ xs = width - 1;
+ gegl_buffer_sample (buffer, xs, y, NULL, &cur, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ xs--;
+ for (int p = s1; p > 0 && xs >= 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ xs--;
+ if (val < cur)
+ cur = val;
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (xd, 0, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ xd--;
+ for (int p = s2 - 1; p > 0 && xd >= 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, xs, y, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (xs > 0)
+ xs--;
+ if (val < cur)
+ cur = val;
+ gegl_buffer_set (buf, GEGL_RECTANGLE (xd, 0, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ xd--;
+ }
+ gegl_buffer_copy (buf, GEGL_RECTANGLE (0, 0, width, 1),
+ GEGL_ABYSS_NONE,
+ buffer, GEGL_RECTANGLE (0, y, width, 1));
+ }
+ }
+ g_object_unref (buf);
+ }
+
+ if (height > 1)
+ {
+ GeglBuffer *buf;
+ const int _s2 = s / 2 + 1;
+ const int _s1 = s - _s2;
+ const int s1 = _s1 > height ? height : _s1;
+ const int s2 = _s2 > height ? height : _s2;
+
+ buf = gegl_buffer_new (GEGL_RECTANGLE (0, 0, 1, height), format);
+
+ for (int x = 0; x < width; ++x)
+ {
+ guchar cur;
+ gint ys = 0;
+ gint yd = 0;
+ gboolean is_first = TRUE;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &cur, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ ys++;
+ for (int p = s2 - 1; p > 0 && ys < height; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ ys++;
+ if (val <= cur)
+ {
+ cur = val;
+ is_first = FALSE;
+ }
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (0, ys, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ yd++;
+
+ if (ys >= height - 1)
+ {
+ guchar se;
+
+ gegl_buffer_sample (buffer, x, height - 1, NULL, &se, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ cur = MIN (cur, se);
+ for (int y = 0; y < height; ++y)
+ {
+ gegl_buffer_set (buffer, GEGL_RECTANGLE (x, y, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+ else
+ {
+ for (int p = s1; p > 0 && yd < height; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (ys < height - 1)
+ ys++;
+ if (val <= cur)
+ {
+ cur = val;
+ is_first = FALSE;
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (0, yd, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ yd++;
+ }
+ for (int p = height - s - 1; p > 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ ys++;
+ if (is_first)
+ {
+ guchar nval;
+ gint nys = ys - 1;
+
+ cur = val;
+ for (int q = s - 2; q > 0; --q)
+ {
+ nys--;
+ gegl_buffer_sample (buffer, x, nys, NULL, &nval, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+
+ if (nval < cur)
+ cur = nval;
+ }
+ nys--;
+
+ gegl_buffer_sample (buffer, x, nys, NULL, &nval, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+
+ if (nval < cur)
+ {
+ cur = nval;
+ is_first = TRUE;
+ }
+ else
+ is_first = FALSE;
+ }
+ else
+ {
+ if (val <= cur)
+ cur = val;
+ else
+ {
+ guchar tmp;
+ gegl_buffer_sample (buffer, x, ys - s, NULL, &tmp, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (cur == tmp)
+ is_first = TRUE;
+ }
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (0, yd, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ yd++;
+ }
+ yd = height - 1;
+ ys = height - 1;
+ gegl_buffer_sample (buffer, x, ys, NULL, &cur, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ ys--;
+ for (int p = s1; p > 0 && ys >= 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ ys--;
+ if (val < cur)
+ cur = val;
+ }
+ gegl_buffer_set (buf, GEGL_RECTANGLE (0, yd, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ yd--;
+ for (int p = s2 - 1; p > 0 && yd >= 0; --p)
+ {
+ guchar val;
+
+ gegl_buffer_sample (buffer, x, ys, NULL, &val, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (ys > 0)
+ ys--;
+ if (val < cur)
+ cur = val;
+ gegl_buffer_set (buf, GEGL_RECTANGLE (0, yd, 1, 1), 0,
+ format, &cur, GEGL_AUTO_ROWSTRIDE);
+ yd--;
+ }
+ gegl_buffer_copy (buf, GEGL_RECTANGLE (0, 0, 1, height),
+ GEGL_ABYSS_NONE,
+ buffer, GEGL_RECTANGLE (x, 0, 1, height));
+ }
+ }
+ g_object_unref (buf);
+ }
+}
+
+static void
+gimp_lineart_denoise (GeglBuffer *buffer,
+ int minimum_area)
+{
+ /* Keep connected regions with significant area. */
+ GQueue *q = g_queue_new ();
+ GArray *region;
+ gint width = gegl_buffer_get_width (buffer);
+ gint height = gegl_buffer_get_height (buffer);
+ gboolean visited[width][height];
+
+ memset (visited, 0, sizeof (gboolean) * width * height);
+ region = g_array_sized_new (TRUE, TRUE, sizeof (Pixel *), minimum_area);
+
+ for (int y = 0; y < height; ++y)
+ for (int x = 0; x < width; ++x)
+ {
+ guchar has_stroke;
+
+ gegl_buffer_sample (buffer, x, y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[x][y])
+ {
+ Pixel *p = g_new (Pixel, 1);
+ int regionSize = 0;
+
+ p->x = x;
+ p->y = y;
+
+ g_queue_push_tail (q, p);
+ visited[x][y] = TRUE;
+
+ while (! g_queue_is_empty (q))
+ {
+ Pixel *p = (Pixel *) g_queue_pop_head (q);
+ gint p2x;
+ gint p2y;
+
+ p2x = p->x + 1;
+ p2y = p->y;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x - 1;
+ p2y = p->y;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x + 1;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x - 1;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x - 1;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+ p2x = p->x + 1;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width && p2y >= 0 && p2y < height)
+ {
+ gegl_buffer_sample (buffer, p2x, p2y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke && ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+ }
+
+ ++regionSize;
+ if (regionSize < minimum_area)
+ g_array_append_val (region, *p);
+ g_free (p);
+ }
+ if (regionSize < minimum_area)
+ {
+ Pixel *pixel = (Pixel *) region->data;
+ gint i = 0;
+
+ for (; i < region->len; i++)
+ {
+ guchar val = 0;
+ gegl_buffer_set (buffer, GEGL_RECTANGLE (pixel->x, pixel->y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ pixel++;
+ }
+ }
+ g_array_remove_range (region, 0, region->len);
+ }
+ }
+ g_array_free (region, TRUE);
+ g_queue_free_full (q, g_free);
+}
+
+static void
+gimp_lineart_compute_normals_curvatures (GeglBuffer *mask,
+ gfloat ***normals,
+ gfloat **curvatures,
+ int normal_estimate_mask_size)
+{
+ GArray *es = gimp_edgelset_new (mask);
+ Edgel **e = (Edgel **) es->data;
+
+ gimp_edgelset_smooth_normals (es, normal_estimate_mask_size);
+ gimp_edgelset_compute_curvature (es);
+
+ while (*e)
+ {
+ const float w = MAX (1e-8f, (*e)->curvature * (*e)->curvature);
+
+ normals[(*e)->x][(*e)->y][0] += w * (*e)->x_normal;
+ normals[(*e)->x][(*e)->y][1] += w * (*e)->y_normal;
+ curvatures[(*e)->x][(*e)->y] = MAX ((*e)->curvature,
+ curvatures[(*e)->x][(*e)->y]);
+ e++;
+ }
+ for (int y = 0; y < gegl_buffer_get_height (mask); ++y)
+ for (int x = 0; x < gegl_buffer_get_width (mask); ++x)
+ {
+ const float _angle = atan2f (normals[x][y][1], normals[x][y][0]);
+ normals[x][y][0] = cosf (_angle);
+ normals[x][y][1] = sinf (_angle);
+ }
+ g_array_free (es, TRUE);
+}
+
+/**
+ * Keep one pixel per connected component of curvature extremums.
+ */
+static GArray *
+gimp_lineart_curvature_extremums (gfloat **curvatures,
+ gint width,
+ gint height)
+{
+ GArray *max_positions;
+ GQueue *q = g_queue_new ();
+ gboolean visited[width][height];
+
+ memset (visited, 0, sizeof (gboolean) * width * height);
+ max_positions = g_array_new (FALSE, TRUE, sizeof (Pixel));
+
+ for (int y = 0; y < height; ++y)
+ for (int x = 0; x < width; ++x)
+ {
+ if ((curvatures[x][y] > 0.0) && ! visited[x][y])
+ {
+ Pixel *p = g_new (Pixel, 1);
+ Pixel max_curvature_pixel = gimp_vector2_new (-1.0, -1.0);
+ gfloat max_curvature = 0.0f;
+ size_t count = 0;
+
+ p->x = x;
+ p->y = y;
+ g_queue_push_tail (q, p);
+ visited[x][y] = TRUE;
+
+ while (! g_queue_is_empty (q))
+ {
+ gfloat c;
+ gint p2x;
+ gint p2y;
+
+ p = (Pixel *) g_queue_pop_head (q);
+ c = curvatures[(gint) p->x][(gint) p->y];
+
+ ++count;
+ curvatures[(gint) p->x][(gint) p->y] = 0.0f;
+
+ p2x = (gint) p->x + 1;
+ p2y = (gint) p->y;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x - 1;
+ p2y = p->y;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x + 1;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x - 1;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x - 1;
+ p2y = p->y + 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ p2x = p->x + 1;
+ p2y = p->y - 1;
+ if (p2x >= 0 && p2x < width &&
+ p2y >= 0 && p2y < height &&
+ curvatures[p2x][p2y] > 0.0 &&
+ ! visited[p2x][p2y])
+ {
+ Pixel *p2 = g_new (Pixel, 1);
+
+ p2->x = p2x;
+ p2->y = p2y;
+ g_queue_push_tail (q, p2);
+ visited[p2x][p2y] = TRUE;
+ }
+
+ if (c > max_curvature)
+ {
+ max_curvature_pixel = *p;
+ max_curvature = c;
+ }
+ g_free (p);
+ }
+ curvatures[(gint) max_curvature_pixel.x][(gint) max_curvature_pixel.y] = max_curvature;
+ g_array_append_val (max_positions, max_curvature_pixel);
+ }
+ }
+ g_queue_free_full (q, g_free);
+
+ return max_positions;
+}
+
+static gint
+gimp_spline_candidate_cmp (const SplineCandidate *a,
+ const SplineCandidate *b,
+ gpointer user_data)
+{
+ /* This comparison actually returns the opposite of common comparison
+ * functions on purpose, as we want the first element on the list to
+ * be the "bigger".
+ */
+ if (a->quality < b->quality)
+ return 1;
+ else if (a->quality > b->quality)
+ return -1;
+ else
+ return 0;
+}
+
+static GList *
+gimp_lineart_find_spline_candidates (GArray *max_positions,
+ gfloat ***normals,
+ gint distance_threshold,
+ gfloat max_angle_deg)
+{
+ GList *candidates = NULL;
+ const float CosMin = cosf (M_PI * (max_angle_deg / 180.0));
+ gint i;
+
+ for (i = 0; i < max_positions->len; i++)
+ {
+ Pixel p1 = g_array_index (max_positions, Pixel, i);
+ gint j;
+
+ for (j = i + 1; j < max_positions->len; j++)
+ {
+ Pixel p2 = g_array_index (max_positions, Pixel, j);
+ const float distance = gimp_vector2_length_val (gimp_vector2_sub_val (p1, p2));
+
+ if (distance <= distance_threshold)
+ {
+ GimpVector2 normalP1;
+ GimpVector2 normalP2;
+ GimpVector2 p1f;
+ GimpVector2 p2f;
+ GimpVector2 p1p2;
+ float cosN;
+ float qualityA;
+ float qualityB;
+ float qualityC;
+ float quality;
+
+ normalP1 = gimp_vector2_new (normals[(gint) p1.x][(gint) p1.y][0],
+ normals[(gint) p1.x][(gint) p1.y][1]);
+ normalP2 = gimp_vector2_new (normals[(gint) p2.x][(gint) p2.y][0],
+ normals[(gint) p2.x][(gint) p2.y][1]);
+ p1f = gimp_vector2_new (p1.x, p1.y);
+ p2f = gimp_vector2_new (p2.x, p2.y);
+ p1p2 = gimp_vector2_sub_val (p2f, p1f);
+
+ cosN = gimp_vector2_inner_product_val (normalP1, (gimp_vector2_neg_val (normalP2)));
+ qualityA = MAX (0.0f, 1 - distance / distance_threshold);
+ qualityB = MAX (0.0f,
+ (float) (gimp_vector2_inner_product_val (normalP1, p1p2) -
gimp_vector2_inner_product_val (normalP2, p1p2)) /
+ distance);
+ qualityC = MAX (0.0f, cosN - CosMin);
+ quality = qualityA * qualityB * qualityC;
+ if (quality > 0)
+ {
+ SplineCandidate *candidate = g_new (SplineCandidate, 1);
+
+ candidate->p1 = p1;
+ candidate->p2 = p2;
+ candidate->quality = quality;
+
+ candidates = g_list_insert_sorted_with_data (candidates, candidate,
+ (GCompareDataFunc) gimp_spline_candidate_cmp,
+ NULL);
+ }
+ }
+ }
+ }
+ return candidates;
+}
+
+static GArray *
+gimp_lineart_discrete_spline (Pixel p0,
+ GimpVector2 n0,
+ Pixel p1,
+ GimpVector2 n1)
+{
+ GArray *points = g_array_new (FALSE, TRUE, sizeof (Pixel));
+ const double a0 = 2 * p0.x - 2 * p1.x + n0.x - n1.x;
+ const double b0 = -3 * p0.x + 3 * p1.x - 2 * n0.x + n1.x;
+ const double c0 = n0.x;
+ const double d0 = p0.x;
+ const double a1 = 2 * p0.y - 2 * p1.y + n0.y - n1.y;
+ const double b1 = -3 * p0.y + 3 * p1.y - 2 * n0.y + n1.y;
+ const double c1 = n0.y;
+ const double d1 = p0.y;
+
+ double t = 0.0;
+ const double dtMin = 1.0 / MAX (fabs (p0.x - p1.x), fabs (p0.y - p1.y));
+ Pixel point = gimp_vector2_new ((gint) round (d0), (gint) round (d1));
+
+ g_array_append_val (points, point);
+
+ while (t <= 1.0)
+ {
+ const double t2 = t * t;
+ const double t3 = t * t2;
+ double dx;
+ double dy;
+ Pixel p = gimp_vector2_new ((gint) round (a0 * t3 + b0 * t2 + c0 * t + d0),
+ (gint) round (a1 * t3 + b1 * t2 + c1 * t + d1));
+
+ /* create gimp_vector2_neq () ? */
+ if (g_array_index (points, Pixel, points->len - 1).x != p.x ||
+ g_array_index (points, Pixel, points->len - 1).y != p.y)
+ {
+ g_array_append_val (points, p);
+ }
+ dx = fabs (3 * a0 * t * t + 2 * b0 * t + c0) + 1e-8;
+ dy = fabs (3 * a1 * t * t + 2 * b1 * t + c1) + 1e-8;
+ t += MIN (dtMin, 0.75 / MAX (dx, dy));
+ }
+ if (g_array_index (points, Pixel, points->len - 1).x != p1.x ||
+ g_array_index (points, Pixel, points->len - 1).y != p1.y)
+ {
+ g_array_append_val (points, p1);
+ }
+ return points;
+}
+
+static gint
+gimp_number_of_transitions (GArray *pixels,
+ GeglBuffer *buffer,
+ gboolean border_value)
+{
+ int result = 0;
+
+ if (pixels->len > 0)
+ {
+ Pixel it = g_array_index (pixels, Pixel, 0);
+ guchar value;
+ gboolean previous;
+ gint i;
+
+ gegl_buffer_sample (buffer, (gint) it.x, (gint) it.y, NULL, &value, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ previous = (gboolean) value;
+
+ /* Starts at the second element. */
+ for (i = 1; i < pixels->len; i++)
+ {
+ gboolean val;
+
+ it = g_array_index (pixels, Pixel, i);
+ if (it.x >= 0 && it.x < gegl_buffer_get_width (buffer) &&
+ it.y >= 0 && it.y < gegl_buffer_get_height (buffer))
+ {
+ guchar value;
+
+ gegl_buffer_sample (buffer, (gint) it.x, (gint) it.y, NULL, &value, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ val = (gboolean) value;
+ }
+ else
+ {
+ val = border_value;
+ }
+ result += (val != previous);
+ previous = val;
+ }
+ }
+
+ return result;
+}
+
+/**
+ * Check whether a set of points will create a 4-connected background
+ * region whose size (i.e. number of pixels) falls within a given interval.
+ */
+static gboolean
+gimp_lineart_curve_creates_region (GeglBuffer *mask,
+ GArray *pixels,
+ int lower_size_limit,
+ int upper_size_limit)
+{
+ const glong max_edgel_count = 2 * (upper_size_limit + 1);
+ Pixel *p = (Pixel*) pixels->data;
+ gint i;
+
+ /* Mark pixels */
+ for (i = 0; i < pixels->len; i++)
+ {
+ if (p->x >= 0 && p->x < gegl_buffer_get_width (mask) &&
+ p->y >= 0 && p->y < gegl_buffer_get_height (mask))
+ {
+ guchar val;
+
+ gegl_buffer_sample (mask, (gint) p->x, (gint) p->y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ val = val ? 3 : 2;
+ gegl_buffer_set (mask, GEGL_RECTANGLE ((gint) p->x, (gint) p->y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ p++;
+ }
+
+ for (i = 0; i < pixels->len; i++)
+ {
+ Pixel p = g_array_index (pixels, Pixel, i);
+
+ for (int direction = 0; direction < 4; ++direction)
+ {
+ if (p.x >= 0 && p.x < gegl_buffer_get_width (mask) &&
+ p.y >= 0 && p.y < gegl_buffer_get_height (mask) &&
+ border_in_direction (mask, p, direction))
+ {
+ Edgel e;
+ guchar val;
+ glong count;
+ glong area;
+
+ gegl_buffer_sample (mask, (gint) p.x, (gint) p.y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((gboolean) (val & (4 << direction)))
+ continue;
+
+ gimp_edgel_init (&e);
+ e.x = p.x;
+ e.y = p.y;
+ e.direction = direction;
+
+ count = gimp_edgel_track_mark (mask, e, max_edgel_count);
+ if ((count != -1) && (count <= max_edgel_count) &&
+ ((area = -1 * gimp_edgel_region_area (mask, e)) >= lower_size_limit) &&
+ (area <= upper_size_limit))
+ {
+ gint j;
+
+ /* Remove marks */
+ for (j = 0; j < pixels->len; j++)
+ {
+ Pixel p2 = g_array_index (pixels, Pixel, j);
+
+ if (p2.x >= 0 && p2.x < gegl_buffer_get_width (mask) &&
+ p2.y >= 0 && p2.y < gegl_buffer_get_height (mask))
+ {
+ guchar val;
+
+ gegl_buffer_sample (mask, (gint) p2.x, (gint) p2.y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ val &= 1;
+ gegl_buffer_set (mask, GEGL_RECTANGLE ((gint) p2.x, (gint) p2.y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+ return TRUE;
+ }
+ }
+ }
+ }
+
+ /* Remove marks */
+ for (i = 0; i < pixels->len; i++)
+ {
+ Pixel p = g_array_index (pixels, Pixel, i);
+
+ if (p.x >= 0 && p.x < gegl_buffer_get_width (mask) &&
+ p.y >= 0 && p.y < gegl_buffer_get_height (mask))
+ {
+ guchar val;
+
+ gegl_buffer_sample (mask, (gint) p.x, (gint) p.y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ val &= 1;
+ gegl_buffer_set (mask, GEGL_RECTANGLE ((gint) p.x, (gint) p.y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+ return FALSE;
+}
+
+static GArray *
+gimp_lineart_line_segment_until_hit (const GeglBuffer *mask,
+ Pixel start,
+ GimpVector2 direction,
+ int size)
+{
+ GeglBuffer *buffer = (GeglBuffer *) mask;
+ gboolean out = FALSE;
+ GArray *points = g_array_new (FALSE, TRUE, sizeof (Pixel));
+ int tmax;
+ GimpVector2 p0 = gimp_vector2_new (start.x, start.y);
+
+ gimp_vector2_mul (&direction, (gdouble) size);
+ direction.x = round (direction.x);
+ direction.y = round (direction.y);
+
+ tmax = MAX (abs ((int) direction.x), abs ((int) direction.y));
+
+ for (int t = 0; t <= tmax; ++t)
+ {
+ GimpVector2 v = gimp_vector2_add_val (p0, gimp_vector2_mul_val (direction, (float)t / tmax));
+ Pixel p;
+
+ p.x = (gint) round (v.x);
+ p.y = (gint) round (v.y);
+ if (p.x >= 0 && p.x < gegl_buffer_get_width (buffer) &&
+ p.y >= 0 && p.y < gegl_buffer_get_height (buffer))
+ {
+ guchar val;
+ gegl_buffer_sample (buffer, p.x, p.y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (out && val)
+ {
+ return points;
+ }
+ out = ! val;
+ }
+ else if (out)
+ {
+ return points;
+ }
+ else
+ {
+ g_array_free (points, TRUE);
+ return g_array_new (FALSE, TRUE, sizeof (Pixel));
+ }
+ g_array_append_val (points, p);
+ }
+
+ g_array_free (points, TRUE);
+ return g_array_new (FALSE, TRUE, sizeof (Pixel));
+}
+
+static gfloat
+gimp_lineart_estimate_stroke_width (GeglBuffer* mask)
+{
+ /* Return the median distance maximum per connected component. */
+ GeglBufferIterator *gi;
+ GeglBuffer *distmap;
+ GeglBuffer *labels;
+ GeglNode *graph;
+ GeglNode *input;
+ GeglNode *op;
+ GeglNode *sink;
+ guint32 label_max = 0;
+ GArray *dmax;
+ gfloat *dmax_data;
+ gfloat res;
+ gint i;
+
+ /* Compute a distance map for the line art. */
+ graph = gegl_node_new ();
+ input = gegl_node_new_child (graph,
+ "operation", "gegl:buffer-source",
+ "buffer", mask,
+ NULL);
+ op = gegl_node_new_child (graph,
+ "operation", "gegl:distance-transform",
+ "metric", GEGL_DISTANCE_METRIC_EUCLIDEAN,
+ "normalize", FALSE,
+ NULL);
+ sink = gegl_node_new_child (graph,
+ "operation", "gegl:buffer-sink",
+ "buffer", &distmap,
+ NULL);
+ gegl_node_connect_to (input, "output",
+ op, "input");
+ gegl_node_connect_to (op, "output",
+ sink, "input");
+ gegl_node_process (sink);
+ g_object_unref (graph);
+
+ labels = gimp_lineart_get_labels (mask, TRUE);
+
+ for (int y = 0; y < gegl_buffer_get_height (mask); ++y)
+ for (int x = 0; x < gegl_buffer_get_width (mask); ++x)
+ {
+ guint8 val;
+
+ gegl_buffer_sample (mask, x, y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (! val)
+ {
+ guint32 label = 0;
+ gegl_buffer_set (labels, GEGL_RECTANGLE (x, y, 1, 1), 0,
+ babl_format_n (babl_type ("u32"), 1),
+ &label, GEGL_AUTO_ROWSTRIDE);
+ }
+ }
+
+ /* Check biggest label. */
+ gi = gegl_buffer_iterator_new (labels, NULL, 0, NULL,
+ GEGL_ACCESS_READ, GEGL_ABYSS_NONE, 1);
+ while (gegl_buffer_iterator_next (gi))
+ {
+ guint32 *data = (guint32*) gi->items[0].data;
+ gint k;
+
+ for (k = 0; k < gi->length; k++)
+ {
+ label_max = MAX (*data, label_max);
+ data++;
+ }
+ }
+
+ if (label_max == 0)
+ {
+ g_object_unref (labels);
+ g_object_unref (distmap);
+ return 0.0;
+ }
+
+ /* Create an array of max distance per label */
+ dmax = g_array_sized_new (FALSE, TRUE, sizeof (gfloat), label_max);
+ g_array_set_size (dmax, label_max);
+ dmax_data = (gfloat *) dmax->data;
+ memset (dmax_data, 0, sizeof (gfloat) * label_max);
+ for (int y = 0; y < gegl_buffer_get_height (distmap); ++y)
+ for (int x = 0; x < gegl_buffer_get_width (distmap); ++x)
+ {
+ guint8 val;
+
+ gegl_buffer_sample (mask, x, y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (val)
+ {
+ guint32 label;
+ gfloat d;
+ gfloat v;
+
+ gegl_buffer_sample (labels, x, y, NULL, &label,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ gimp_assert (label);
+ v = dmax_data[label - 1];
+ gegl_buffer_sample (distmap, x, y, NULL, &d,
+ babl_format ("Y float"),
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (d > v)
+ {
+ dmax_data[label - 1] = d;
+ }
+ }
+ }
+
+ /* Sort and crop labels with distance 0. */
+ g_array_sort (dmax, float_compare);
+ for (i = 0; i < label_max; i++)
+ {
+ if (dmax_data[i] != 0.0)
+ break;
+ }
+
+ res = dmax_data[i + (label_max - i) / 2];
+ g_array_unref (dmax);
+ g_object_unref (labels);
+ g_object_unref (distmap);
+
+ return 2.0 * res;
+}
+
+static guint
+visited_hash_fun (Pixel *key)
+{
+ /* Cantor pairing function. */
+ return (key->x + key->y) * (key->x + key->y + 1) / 2 + key->y;
+}
+
+static gboolean
+visited_equal_fun (Pixel *e1,
+ Pixel *e2)
+{
+ return (e1->x == e2->x && e1->y == e2->y);
+}
+
+static gint
+float_compare (gconstpointer p1,
+ gconstpointer p2)
+{
+ const gfloat *i1 = (gfloat *) p1;
+ const gfloat *i2 = (gfloat *) p2;
+
+ return (*i1 > *i2) ? 1: (*i1 < *i2) ? -1 : 0;
+}
+
+static inline gboolean
+border_in_direction (GeglBuffer *mask,
+ Pixel p,
+ int direction)
+{
+ gint px = (gint) p.x + DeltaX[direction];
+ gint py = (gint) p.y + DeltaY[direction];
+
+ if (px >= 0 && px < gegl_buffer_get_width (mask) &&
+ py >= 0 && py < gegl_buffer_get_height (mask))
+ {
+ guchar val;
+
+ gegl_buffer_sample (mask, px, py, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ return ! ((gboolean) val);
+ }
+ return TRUE;
+}
+
+static inline GimpVector2
+pair2normal (Pixel p,
+ gfloat ***normals)
+{
+ return gimp_vector2_new (normals[(gint) p.x][(gint) p.y][0],
+ normals[(gint) p.x][(gint) p.y][1]);
+}
+/* Edgel functions */
+
+static Edgel *
+gimp_edgel_new (int x,
+ int y,
+ Direction direction)
+{
+ Edgel *edgel = g_new (Edgel, 1);
+
+ edgel->x = x;
+ edgel->y = y;
+ edgel->direction = direction;
+
+ gimp_edgel_init (edgel);
+
+ return edgel;
+}
+
+static void
+gimp_edgel_init (Edgel *edgel)
+{
+ edgel->x_normal = 0;
+ edgel->y_normal = 0;
+ edgel->curvature = 0;
+ edgel->next = edgel->previous = G_MAXUINT;
+}
+
+static void
+gimp_edgel_clear (Edgel **edgel)
+{
+ g_clear_pointer (edgel, g_free);
+}
+
+static int
+gimp_edgel_cmp (const Edgel* e1,
+ const Edgel* e2)
+{
+ gimp_assert (e1 && e2);
+
+ if ((e1->x == e2->x) && (e1->y == e2->y) &&
+ (e1->direction == e2->direction))
+ return 0;
+ else if ((e1->y < e2->y) || (e1->y == e2->y && e1->x < e2->x) ||
+ (e1->y == e2->y && e1->x == e2->x && e1->direction < e2->direction))
+ return -1;
+ else
+ return 1;
+}
+
+static guint
+edgel2index_hash_fun (Edgel *key)
+{
+ /* Cantor pairing function.
+ * Was not sure how to use the direction though. :-/
+ */
+ return (key->x + key->y) * (key->x + key->y + 1) / 2 + key->y * key->direction;
+}
+
+static gboolean
+edgel2index_equal_fun (Edgel *e1,
+ Edgel *e2)
+{
+ return (e1->x == e2->x && e1->y == e2->y &&
+ e1->direction == e2->direction);
+}
+
+/**
+ * @mask;
+ * @edgel:
+ * @size_limit:
+ *
+ * Track a border, marking inner pixels with a bit corresponding to the
+ * edgel traversed (4 << direction) for direction in {0,1,2,3}.
+ * Stop tracking after @size_limit edgels have been visited.
+ *
+ * Returns: Number of visited edgels, or -1 if an already visited edgel
+ * has been encountered.
+ */
+static glong
+gimp_edgel_track_mark (GeglBuffer *mask,
+ Edgel edgel,
+ long size_limit)
+{
+ Edgel start = edgel;
+ long count = 1;
+
+ do
+ {
+ guchar val;
+
+ gimp_edgelset_next8 (mask, &edgel, &edgel);
+ gegl_buffer_sample (mask, edgel.x, edgel.y, NULL, &val,
+ NULL, GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (val & 2)
+ {
+ /* Only mark pixels of the spline/segment */
+ if (val & (4 << edgel.direction))
+ return -1;
+
+ /* Mark edgel in pixel (1 == In Mask, 2 == Spline/Segment) */
+ val |= (4 << edgel.direction);
+ gegl_buffer_set (mask, GEGL_RECTANGLE (edgel.x, edgel.y, 1, 1), 0,
+ NULL, &val, GEGL_AUTO_ROWSTRIDE);
+ }
+ if (gimp_edgel_cmp (&edgel, &start) != 0)
+ ++count;
+ }
+ while (gimp_edgel_cmp (&edgel, &start) != 0 && count <= size_limit);
+
+ return count;
+}
+
+static glong
+gimp_edgel_region_area (const GeglBuffer *mask,
+ Edgel start_edgel)
+{
+ Edgel edgel = start_edgel;
+ long area = 0;
+
+ do
+ {
+ if (edgel.direction == XPlusDirection)
+ area += edgel.x;
+ else if (edgel.direction == XMinusDirection)
+ area -= edgel.x - 1;
+
+ gimp_edgelset_next8 (mask, &edgel, &edgel);
+ }
+ while (gimp_edgel_cmp (&edgel, &start_edgel) != 0);
+
+ return area;
+}
+
+/* Edgel sets */
+
+static GArray *
+gimp_edgelset_new (GeglBuffer *buffer)
+{
+ GArray *set;
+ GHashTable *edgel2index;
+ int lx = gegl_buffer_get_width (buffer) - 1;
+ int ly = gegl_buffer_get_height (buffer) - 1;
+
+ set = g_array_new (TRUE, TRUE, sizeof (Edgel *));
+ g_array_set_clear_func (set, (GDestroyNotify) gimp_edgel_clear);
+
+ edgel2index = g_hash_table_new ((GHashFunc) edgel2index_hash_fun,
+ (GEqualFunc) edgel2index_equal_fun);
+
+ for (int y = 0; y < (int) gegl_buffer_get_height (buffer); ++y)
+ for (int x = 0; x < (int) gegl_buffer_get_width (buffer); ++x)
+ {
+ guchar has_stroke;
+
+ gegl_buffer_sample (buffer, x, y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (has_stroke)
+ {
+ gegl_buffer_sample (buffer, x, y - 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (! y || ! has_stroke)
+ gimp_edgelset_add (set, x, y, YMinusDirection, edgel2index);
+
+ gegl_buffer_sample (buffer, x, y + 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((y == ly) || ! has_stroke)
+ gimp_edgelset_add (set, x, y, YPlusDirection, edgel2index);
+
+ gegl_buffer_sample (buffer, x - 1, y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (!x || ! has_stroke)
+ gimp_edgelset_add (set, x, y, XMinusDirection, edgel2index);
+
+ gegl_buffer_sample (buffer, x + 1, y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((x == lx) || ! has_stroke)
+ gimp_edgelset_add (set, x, y, XPlusDirection, edgel2index);
+ }
+ }
+ gimp_edgelset_build_graph (set, buffer, edgel2index);
+ g_hash_table_destroy (edgel2index);
+ gimp_edgelset_init_normals (set);
+
+ return set;
+}
+
+static void
+gimp_edgelset_add (GArray *set,
+ int x,
+ int y,
+ Direction direction,
+ GHashTable *edgel2index)
+{
+ Edgel *edgel = gimp_edgel_new (x, y, direction);
+ unsigned long position = set->len;
+
+ g_array_append_val (set, edgel);
+ g_hash_table_insert (edgel2index, edgel, GUINT_TO_POINTER (position));
+}
+
+static void
+gimp_edgelset_init_normals (GArray *set)
+{
+ Edgel **e = (Edgel**) set->data;
+
+ while (*e)
+ {
+ GimpVector2 n = Direction2Normal[(*e)->direction];
+
+ (*e)->x_normal = n.x;
+ (*e)->y_normal = n.y;
+ e++;
+ }
+}
+
+static void
+gimp_edgelset_smooth_normals (GArray *set,
+ int mask_size)
+{
+ const gfloat sigma = mask_size * 0.775;
+ const gfloat den = 2 * sigma * sigma;
+ gfloat weights[65];
+ GimpVector2 smoothed_normal;
+ gint i;
+
+ gimp_assert (mask_size <= 65);
+
+ weights[0] = 1.0f;
+ for (int i = 1; i <= mask_size; ++i)
+ weights[i] = expf (-(i * i) / den);
+
+ for (i = 0; i < set->len; i++)
+ {
+ Edgel *it = g_array_index (set, Edgel*, i);
+ Edgel *edgel_before = g_array_index (set, Edgel*, it->previous);
+ Edgel *edgel_after = g_array_index (set, Edgel*, it->next);
+ int n = mask_size;
+ int i = 1;
+
+ smoothed_normal = Direction2Normal[it->direction];
+ while (n-- && (edgel_after != edgel_before))
+ {
+ smoothed_normal = gimp_vector2_add_val (smoothed_normal,
+ gimp_vector2_mul_val
(Direction2Normal[edgel_before->direction], weights[i]));
+ smoothed_normal = gimp_vector2_add_val (smoothed_normal,
+ gimp_vector2_mul_val
(Direction2Normal[edgel_after->direction], weights[i]));
+ edgel_before = g_array_index (set, Edgel *, edgel_before->previous);
+ edgel_after = g_array_index (set, Edgel *, edgel_after->next);
+ ++i;
+ }
+ gimp_vector2_normalize (&smoothed_normal);
+ it->x_normal = smoothed_normal.x;
+ it->y_normal = smoothed_normal.y;
+ }
+}
+
+static void
+gimp_edgelset_compute_curvature (GArray *set)
+{
+ gint i;
+
+ for (i = 0; i < set->len; i++)
+ {
+ Edgel *it = g_array_index (set, Edgel*, i);
+ Edgel *previous = g_array_index (set, Edgel *, it->previous);
+ Edgel *next = g_array_index (set, Edgel *, it->next);
+ GimpVector2 n_prev = gimp_vector2_new (previous->x_normal, previous->y_normal);
+ GimpVector2 n_next = gimp_vector2_new (next->x_normal, next->y_normal);
+ GimpVector2 diff = gimp_vector2_mul_val (gimp_vector2_sub_val (n_next, n_prev),
+ 0.5);
+ const float c = gimp_vector2_length_val (diff);
+ const float crossp = n_prev.x * n_next.y - n_prev.y * n_next.x;
+
+ it->curvature = (crossp > 0.0f) ? c : 0.0f;
+ ++it;
+ }
+}
+
+static void
+gimp_edgelset_build_graph (GArray *set,
+ GeglBuffer *buffer,
+ GHashTable *edgel2index)
+{
+ Edgel edgel;
+ gint i;
+
+ for (i = 0; i < set->len; i++)
+ {
+ Edgel *neighbor;
+ Edgel *it = g_array_index (set, Edgel *, i);
+ guint neighbor_pos;
+
+ gimp_edgelset_next8 (buffer, it, &edgel);
+
+ gimp_assert (g_hash_table_contains (edgel2index, &edgel));
+ neighbor_pos = GPOINTER_TO_UINT (g_hash_table_lookup (edgel2index, &edgel));
+ it->next = neighbor_pos;
+ neighbor = g_array_index (set, Edgel *, neighbor_pos);
+ neighbor->previous = i;
+ }
+}
+
+static void
+gimp_edgelset_next8 (const GeglBuffer *buffer,
+ Edgel *it,
+ Edgel *n)
+{
+ const int lx = gegl_buffer_get_width ((GeglBuffer *) buffer) - 1;
+ const int ly = gegl_buffer_get_height ((GeglBuffer *) buffer) - 1;
+ guchar has_stroke;
+
+ n->x = it->x;
+ n->y = it->y;
+ n->direction = it->direction;
+ switch (n->direction)
+ {
+ case XPlusDirection:
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x + 1, n->y + 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((n->x != lx) && (n->y != ly) && has_stroke)
+ {
+ ++(n->y);
+ ++(n->x);
+ n->direction = YMinusDirection;
+ }
+ else
+ {
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x, n->y + 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((n->y != ly) && has_stroke)
+ {
+ ++(n->y);
+ }
+ else
+ {
+ n->direction = YPlusDirection;
+ }
+ }
+ break;
+ case YMinusDirection:
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x + 1, n->y - 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((n->x != lx) && n->y && has_stroke)
+ {
+ ++(n->x);
+ --(n->y);
+ n->direction = XMinusDirection;
+ }
+ else
+ {
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x + 1, n->y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if ((n->x != lx) && has_stroke)
+ {
+ ++(n->x);
+ }
+ else
+ {
+ n->direction = XPlusDirection;
+ }
+ }
+ break;
+ case XMinusDirection:
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x - 1, n->y - 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (n->x && n->y && has_stroke)
+ {
+ --(n->x);
+ --(n->y);
+ n->direction = YPlusDirection;
+ }
+ else
+ {
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x, n->y - 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (n->y && has_stroke)
+ {
+ --(n->y);
+ }
+ else
+ {
+ n->direction = YMinusDirection;
+ }
+ }
+ break;
+ case YPlusDirection:
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x - 1, n->y + 1, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (n->x && (n->y != ly) && has_stroke)
+ {
+ --(n->x);
+ ++(n->y);
+ n->direction = XPlusDirection;
+ }
+ else
+ {
+ gegl_buffer_sample ((GeglBuffer *) buffer, n->x - 1, n->y, NULL, &has_stroke, NULL,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+ if (n->x && has_stroke)
+ {
+ --(n->x);
+ }
+ else
+ {
+ n->direction = XMinusDirection;
+ }
+ }
+ break;
+ default:
+ gimp_assert (FALSE);
+ break;
+ }
+}
diff --git a/app/core/gimplineart.h b/app/core/gimplineart.h
new file mode 100644
index 0000000000..fef94f3533
--- /dev/null
+++ b/app/core/gimplineart.h
@@ -0,0 +1,43 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * Copyright (C) 2017 Sébastien Fourey & David Tchumperlé
+ * Copyright (C) 2018 Jehan
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_LINEART__
+#define __GIMP_LINEART__
+
+
+GeglBuffer * gimp_lineart_close (GeglBuffer *line_art,
+ gboolean select_transparent,
+ gfloat stroke_threshold,
+ gint erosion,
+ gint minimal_lineart_area,
+ gint normal_estimate_mask_size,
+ gfloat end_point_rate,
+ gint spline_max_length,
+ gfloat spline_max_angle,
+ gint end_point_connectivity,
+ gfloat spline_roundness,
+ gboolean allow_self_intersections,
+ gint created_regions_significant_area,
+ gint created_regions_minimum_area,
+ gboolean small_segments_from_spline_sources,
+ gint segments_max_length);
+
+
+#endif /* __GIMP_LINEART__ */
diff --git a/app/core/gimppickable-contiguous-region.c b/app/core/gimppickable-contiguous-region.c
index 66c00fa620..ae6c5d14a5 100644
--- a/app/core/gimppickable-contiguous-region.c
+++ b/app/core/gimppickable-contiguous-region.c
@@ -31,6 +31,7 @@
#include "gegl/gimp-babl.h"
#include "gimp-utils.h" /* GIMP_TIMER */
+#include "gimplineart.h"
#include "gimppickable.h"
#include "gimppickable-contiguous-region.h"
@@ -114,6 +115,7 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable *pickable,
gint n_components;
gboolean has_alpha;
gfloat start_col[MAX_CHANNELS];
+ gboolean free_src_buffer = FALSE;
g_return_val_if_fail (GIMP_IS_PICKABLE (pickable), NULL);
@@ -143,6 +145,58 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable *pickable,
select_transparent = FALSE;
}
+ if (select_criterion == GIMP_SELECT_CRITERION_LINE_ART)
+ {
+ /* For smart selection, we generate a binarized image with close
+ * regions, then run a composite selection with no threshold on
+ * this intermediate buffer.
+ */
+ GIMP_TIMER_START();
+ src_buffer = gimp_lineart_close (src_buffer,
+ select_transparent,
+ /*contour_detection_level,*/
+ 0.92,
+ /* erosion, */
+ -1,
+ /*minimal_lineart_area,*/
+ 5,
+ /*normal_estimate_mask_size,*/
+ 5,
+ /*end_point_rate,*/
+ 0.85,
+ /*spline_max_length,*/
+ 60,
+ /*spline_max_angle,*/
+ 90.0,
+ /*end_point_connectivity,*/
+ 2,
+ /*spline_roundness,*/
+ 1.0,
+ /*allow_self_intersections,*/
+ TRUE,
+ /*created_regions_significant_area,*/
+ 4,
+ /*created_regions_minimum_area,*/
+ 100,
+ /*small_segments_from_spline_sources,*/
+ TRUE,
+ /*segments_max_length*/
+ 20);
+ free_src_buffer = TRUE;
+ antialias = FALSE;
+ threshold = 0.0;
+ select_transparent = FALSE;
+ select_criterion = GIMP_SELECT_CRITERION_COMPOSITE;
+ diagonal_neighbors = FALSE;
+
+ format = choose_format (src_buffer, select_criterion,
+ &n_components, &has_alpha);
+ gegl_buffer_sample (src_buffer, x, y, NULL, start_col, format,
+ GEGL_SAMPLER_NEAREST, GEGL_ABYSS_NONE);
+
+ GIMP_TIMER_END("close line-art");
+ }
+
extent = *gegl_buffer_get_extent (src_buffer);
mask_buffer = gegl_buffer_new (&extent, babl_format ("Y float"));
@@ -160,6 +214,8 @@ gimp_pickable_contiguous_region_by_seed (GimpPickable *pickable,
GIMP_TIMER_END("foo");
}
+ if (free_src_buffer)
+ g_object_unref (src_buffer);
return mask_buffer;
}
@@ -295,6 +351,10 @@ choose_format (GeglBuffer *buffer,
format = babl_format ("CIE LCH(ab) alpha float");
break;
+ case GIMP_SELECT_CRITERION_LINE_ART:
+ format = babl_format ("Y'A u8");
+ break;
+
default:
g_return_val_if_reached (NULL);
break;
@@ -385,6 +445,10 @@ pixel_difference (const gfloat *col1,
max = fabs (col1[2] - col2[2]) / 360.0;
max = MIN (max, 1.0 - max);
break;
+
+ case GIMP_SELECT_CRITERION_LINE_ART:
+ /* Smart selection is handled before. */
+ g_return_val_if_reached (0.0);
}
}
@@ -608,7 +672,7 @@ find_contiguous_region (GeglBuffer *src_buffer,
row = g_new (gfloat, gegl_buffer_get_width (src_buffer) * n_components);
#endif
- src_sampler = gegl_buffer_sampler_new (src_buffer,
+ src_sampler = gegl_buffer_sampler_new (src_buffer,
format, GEGL_SAMPLER_NEAREST);
segment_queue = g_queue_new ();
diff --git a/libgimpbase/gimpbaseenums.c b/libgimpbase/gimpbaseenums.c
index ad87b7523b..ec71c906e0 100644
--- a/libgimpbase/gimpbaseenums.c
+++ b/libgimpbase/gimpbaseenums.c
@@ -1642,6 +1642,7 @@ gimp_select_criterion_get_type (void)
{ GIMP_SELECT_CRITERION_LCH_L, "GIMP_SELECT_CRITERION_LCH_L", "lch-l" },
{ GIMP_SELECT_CRITERION_LCH_C, "GIMP_SELECT_CRITERION_LCH_C", "lch-c" },
{ GIMP_SELECT_CRITERION_LCH_H, "GIMP_SELECT_CRITERION_LCH_H", "lch-h" },
+ { GIMP_SELECT_CRITERION_LINE_ART, "GIMP_SELECT_CRITERION_LINE_ART", "line-art" },
{ 0, NULL, NULL }
};
@@ -1658,6 +1659,7 @@ gimp_select_criterion_get_type (void)
{ GIMP_SELECT_CRITERION_LCH_L, NC_("select-criterion", "LCh Lightness"), NULL },
{ GIMP_SELECT_CRITERION_LCH_C, NC_("select-criterion", "LCh Chroma"), NULL },
{ GIMP_SELECT_CRITERION_LCH_H, NC_("select-criterion", "LCh Hue"), NULL },
+ { GIMP_SELECT_CRITERION_LINE_ART, NC_("select-criterion", "Line Art"), NULL },
{ 0, NULL, NULL }
};
diff --git a/libgimpbase/gimpbaseenums.h b/libgimpbase/gimpbaseenums.h
index 45bf8da201..bd2631349c 100644
--- a/libgimpbase/gimpbaseenums.h
+++ b/libgimpbase/gimpbaseenums.h
@@ -1258,6 +1258,7 @@ typedef enum
* @GIMP_SELECT_CRITERION_LCH_L: LCh Lightness
* @GIMP_SELECT_CRITERION_LCH_C: LCh Chroma
* @GIMP_SELECT_CRITERION_LCH_H: LCh Hue
+ * @GIMP_SELECT_CRITERION_LINE_ART: Line Art
*
* Criterions for color similarity.
**/
@@ -1278,6 +1279,7 @@ typedef enum
GIMP_SELECT_CRITERION_LCH_L, /*< desc="LCh Lightness" >*/
GIMP_SELECT_CRITERION_LCH_C, /*< desc="LCh Chroma" >*/
GIMP_SELECT_CRITERION_LCH_H, /*< desc="LCh Hue" >*/
+ GIMP_SELECT_CRITERION_LINE_ART, /*< desc="Line Art" >*/
} GimpSelectCriterion;
diff --git a/libgimpwidgets/gimppropwidgets.c b/libgimpwidgets/gimppropwidgets.c
index b3cbcd5f81..e91edf65e0 100644
--- a/libgimpwidgets/gimppropwidgets.c
+++ b/libgimpwidgets/gimppropwidgets.c
@@ -553,7 +553,7 @@ gimp_prop_enum_combo_box_new (GObject *config,
{
/* ditto */
store = gimp_enum_store_new_with_values (param_spec->value_type,
- 11,
+ 12,
GIMP_SELECT_CRITERION_COMPOSITE,
GIMP_SELECT_CRITERION_R,
GIMP_SELECT_CRITERION_G,
@@ -564,7 +564,8 @@ gimp_prop_enum_combo_box_new (GObject *config,
GIMP_SELECT_CRITERION_V,
GIMP_SELECT_CRITERION_LCH_L,
GIMP_SELECT_CRITERION_LCH_C,
- GIMP_SELECT_CRITERION_LCH_H);
+ GIMP_SELECT_CRITERION_LCH_H,
+ GIMP_SELECT_CRITERION_LINE_ART);
}
if (store)
diff --git a/pdb/enums.pl b/pdb/enums.pl
index a04d88b62d..1efe0318c7 100644
--- a/pdb/enums.pl
+++ b/pdb/enums.pl
@@ -547,7 +547,8 @@ package Gimp::CodeGen::enums;
GIMP_SELECT_CRITERION_A
GIMP_SELECT_CRITERION_LCH_L
GIMP_SELECT_CRITERION_LCH_C
- GIMP_SELECT_CRITERION_LCH_H) ],
+ GIMP_SELECT_CRITERION_LCH_H
+ GIMP_SELECT_CRITERION_LINE_ART) ],
mapping => { GIMP_SELECT_CRITERION_COMPOSITE => '0',
GIMP_SELECT_CRITERION_R => '1',
GIMP_SELECT_CRITERION_G => '2',
@@ -558,7 +559,8 @@ package Gimp::CodeGen::enums;
GIMP_SELECT_CRITERION_A => '7',
GIMP_SELECT_CRITERION_LCH_L => '8',
GIMP_SELECT_CRITERION_LCH_C => '9',
- GIMP_SELECT_CRITERION_LCH_H => '10' }
+ GIMP_SELECT_CRITERION_LCH_H => '10',
+ GIMP_SELECT_CRITERION_LINE_ART => '11' }
},
GimpSizeType =>
{ contig => 1,
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