gimp/plug-ins/common/nl-filter.c

1147 lines
39 KiB
C

/**************************************************
* file: nlfilt/nlfilt.c
*
* Copyright (c) 1997 Eric L. Hernes (erich@rrnet.com)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Algorithm fixes, V2.0 compatibility by David Hodson hodsond@ozemail.com.au
*/
#include "config.h"
#include <string.h>
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
#include "libgimp/stdplugins-intl.h"
#define PLUG_IN_PROC "plug-in-nl-filter"
#define PLUG_IN_BINARY "nl-filter"
#define PLUG_IN_ROLE "gimp-nl-filter"
typedef struct
{
gdouble alpha;
gdouble radius;
gint filter;
} NLFilterValues;
typedef enum
{
filter_alpha_trim,
filter_opt_est,
filter_edge_enhance
} FilterType;
typedef struct _Nlfilter Nlfilter;
typedef struct _NlfilterClass NlfilterClass;
struct _Nlfilter
{
GimpPlugIn parent_instance;
};
struct _NlfilterClass
{
GimpPlugInClass parent_class;
};
#define NLFILTER_TYPE (nlfilter_get_type ())
#define NLFILTER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), NLFILTER_TYPE, Nlfilter))
GType nlfilter_get_type (void) G_GNUC_CONST;
static GList * nlfilter_query_procedures (GimpPlugIn *plug_in);
static GimpProcedure * nlfilter_create_procedure (GimpPlugIn *plug_in,
const gchar *name);
static GimpValueArray * nlfilter_run (GimpProcedure *procedure,
GimpRunMode run_mode,
GimpImage *image,
GimpDrawable **drawables,
GimpProcedureConfig *config,
gpointer run_data);
static void nlfilter (GObject *config,
GimpDrawable *drawable,
GimpPreview *preview);
static void nlfilter_preview (GtkWidget *widget,
GObject *config);
static gboolean nlfilter_dialog (GimpProcedure *procedure,
GObject *config,
GimpDrawable *drawable);
static gint nlfiltInit (gdouble alpha,
gdouble radius,
FilterType filter);
static void nlfiltRow (guchar *srclast,
guchar *srcthis,
guchar *srcnext,
guchar *dst,
gint width,
gint bpp,
gint filtno);
G_DEFINE_TYPE (Nlfilter, nlfilter, GIMP_TYPE_PLUG_IN)
GIMP_MAIN (NLFILTER_TYPE)
DEFINE_STD_SET_I18N
static void
nlfilter_class_init (NlfilterClass *klass)
{
GimpPlugInClass *plug_in_class = GIMP_PLUG_IN_CLASS (klass);
plug_in_class->query_procedures = nlfilter_query_procedures;
plug_in_class->create_procedure = nlfilter_create_procedure;
plug_in_class->set_i18n = STD_SET_I18N;
}
static void
nlfilter_init (Nlfilter *nlfilter)
{
}
static GList *
nlfilter_query_procedures (GimpPlugIn *plug_in)
{
return g_list_append (NULL, g_strdup (PLUG_IN_PROC));
}
static GimpProcedure *
nlfilter_create_procedure (GimpPlugIn *plug_in,
const gchar *name)
{
GimpProcedure *procedure = NULL;
if (! strcmp (name, PLUG_IN_PROC))
{
procedure = gimp_image_procedure_new (plug_in, name,
GIMP_PDB_PROC_TYPE_PLUGIN,
nlfilter_run, NULL, NULL);
gimp_procedure_set_image_types (procedure, "RGB, GRAY");
gimp_procedure_set_sensitivity_mask (procedure,
GIMP_PROCEDURE_SENSITIVE_DRAWABLE);
gimp_procedure_set_menu_label (procedure, _("_NL Filter..."));
gimp_procedure_add_menu_path (procedure,"<Image>/Filters/Enhance");
gimp_procedure_set_documentation (procedure,
_("Nonlinear swiss army knife filter"),
_("This is the pnmnlfilt, in GIMP's "
"clothing. See the pnmnlfilt manpage "
"for details."),
name);
gimp_procedure_set_attribution (procedure,
"Graeme W. Gill, GIMP 0.99 plug-in "
"by Eric L. Hernes",
"Graeme W. Gill, Eric L. Hernes",
"1997");
gimp_procedure_add_double_argument (procedure, "alpha",
_("_Alpha"),
_("The amount of the filter to apply"),
0, 1, 0.3,
G_PARAM_READWRITE);
gimp_procedure_add_double_argument (procedure, "radius",
_("Ra_dius"),
_("The filter radius"),
1.0 / 3.0, 1, 1.0 / 3.0,
G_PARAM_READWRITE);
gimp_procedure_add_choice_argument (procedure, "filter",
_("_Filter"),
_("The Filter to Run"),
gimp_choice_new_with_values ("alpha-trim", filter_alpha_trim, _("Alpha trimmed mean"), NULL,
"optimal-estimation", filter_opt_est, _("Optimal estimation"), NULL,
"edge-enhancement", filter_edge_enhance, _("Edge enhancement"), NULL,
NULL),
"alpha-trim",
G_PARAM_READWRITE);
}
return procedure;
}
static GimpValueArray *
nlfilter_run (GimpProcedure *procedure,
GimpRunMode run_mode,
GimpImage *image,
GimpDrawable **drawables,
GimpProcedureConfig *config,
gpointer run_data)
{
GimpDrawable *drawable;
gegl_init (NULL, NULL);
if (gimp_core_object_array_get_length ((GObject **) drawables) != 1)
{
GError *error = NULL;
g_set_error (&error, GIMP_PLUG_IN_ERROR, 0,
_("Procedure '%s' only works with one drawable."),
gimp_procedure_get_name (procedure));
return gimp_procedure_new_return_values (procedure,
GIMP_PDB_CALLING_ERROR,
error);
}
else
{
drawable = drawables[0];
}
if (run_mode == GIMP_RUN_INTERACTIVE && ! nlfilter_dialog (procedure, G_OBJECT (config), drawable))
return gimp_procedure_new_return_values (procedure,
GIMP_PDB_CANCEL,
NULL);
nlfilter (G_OBJECT (config), drawable, NULL);
if (run_mode != GIMP_RUN_NONINTERACTIVE)
gimp_displays_flush ();
return gimp_procedure_new_return_values (procedure, GIMP_PDB_SUCCESS, NULL);
}
/* pnmnlfilt.c - 4 in 1 (2 non-linear) filter
** - smooth an anyimage
** - do alpha trimmed mean filtering on an anyimage
** - do optimal estimation smoothing on an anyimage
** - do edge enhancement on an anyimage
**
** Version 1.0
**
** The implementation of an alpha-trimmed mean filter
** is based on the description in IEEE CG&A May 1990
** Page 23 by Mark E. Lee and Richard A. Redner.
**
** The paper recommends using a hexagon sampling region around each
** pixel being processed, allowing an effective sub pixel radius to be
** specified. The hexagon values are sythesised by area sampling the
** rectangular pixels with a hexagon grid. The seven hexagon values
** obtained from the 3x3 pixel grid are used to compute the alpha
** trimmed mean. Note that an alpha value of 0.0 gives a conventional
** mean filter (where the radius controls the contribution of
** surrounding pixels), while a value of 0.5 gives a median filter.
** Although there are only seven values to trim from before finding
** the mean, the algorithm has been extended from that described in
** CG&A by using interpolation, to allow a continuous selection of
** alpha value between and including 0.0 to 0.5 The useful values
** for radius are between 0.3333333 (where the filter will have no
** effect because only one pixel is sampled), to 1.0, where all
** pixels in the 3x3 grid are sampled.
**
** The optimal estimation filter is taken from an article "Converting Dithered
** Images Back to Gray Scale" by Allen Stenger, Dr Dobb's Journal, November
** 1992, and this article references "Digital Image Enhancement andNoise Filtering by
** Use of Local Statistics", Jong-Sen Lee, IEEE Transactions on Pattern Analysis and
** Machine Intelligence, March 1980.
**
** Also borrow the technique used in pgmenhance(1) to allow edge
** enhancement if the alpha value is negative.
**
** Author:
** Graeme W. Gill, 30th Jan 1993
** graeme@labtam.oz.au
**
** Permission is hereby granted, to use, copy, modify, distribute,
** and sell this software and its associated documentation files
** (the "Software") for any purpose without fee, provided
** that:
**
** 1) The above copyright notices and this permission notice
** accompany all source code copies of the Software and
** related documentation.
** and
**
** 2) If executable code based on the Software only is distributed,
** then the accompanying documentation must acknowledge that
** "this software is based in part on the work of Graeme W. Gill".
** and
**
** 3) It is accepted that Graeme W. Gill (the "Author") accepts
** NO LIABILITY for damages of any kind. The Software is
** provided without fee by the Author "AS-IS" and without
** warranty of any kind, express, implied or otherwise,
** including without limitation, any warranty of merchantability
** or fitness for a particular purpose.
** and
**
** 4) These conditions apply to any software derived from or based
** on the Software, not just to the unmodified library.
**
*/
/* ************************************************** */
/* Hexagon intersecting square area functions */
/* Compute the area of the intersection of a triangle */
/* and a rectangle */
static gdouble triang_area(gdouble, gdouble, gdouble, gdouble, gdouble,
gdouble, gdouble, gdouble, gint);
static gdouble rectang_area(gdouble, gdouble, gdouble, gdouble,
gdouble, gdouble, gdouble, gdouble);
static gdouble hex_area(gdouble, gdouble, gdouble, gdouble, gdouble);
static gint atfilt0 (gint *p);
static gint atfilt1 (gint *p);
static gint atfilt2 (gint *p);
static gint atfilt3 (gint *p);
static gint atfilt4 (gint *p);
static gint atfilt5 (gint *p);
gint (*atfuncs[6])(gint *) =
{
atfilt0,
atfilt1,
atfilt2,
atfilt3,
atfilt4,
atfilt5
};
static gint noisevariance;
#define MXIVAL 255 /* maximum input value */
#define NOIVAL (MXIVAL + 1) /* number of possible input values */
#define SCALEB 8 /* scale bits */
#define SCALE (1 << SCALEB) /* scale factor */
#define CSCALEB 2 /* coarse scale bits */
#define CSCALE (1 << CSCALEB) /* coarse scale factor */
#define MXCSVAL (MXIVAL * CSCALE) /* maximum coarse scaled values */
#define NOCSVAL (MXCSVAL + 1) /* number of coarse scaled values */
#define SCTOCSC(x) ((x) >> (SCALEB - CSCALEB)) /* convert from scaled to coarse scaled */
#define CSCTOSC(x) ((x) << (SCALEB - CSCALEB)) /* convert from course scaled to scaled */
/* round and scale floating point to scaled integer */
#define SROUND(x) ((gint)(((x) * (gdouble)SCALE) + 0.5))
/* round and un-scale scaled integer value */
#define RUNSCALE(x) (((x) + (1 << (SCALEB-1))) >> SCALEB) /* rounded un-scale */
#define UNSCALE(x) ((x) >> SCALEB)
/* Note: modified by David Hodson, nlfiltRow now accesses
* srclast, srcthis, and srcnext from [-bpp] to [width*bpp-1].
* Beware if you use this code anywhere else!
*/
static void
nlfiltRow (guchar *srclast, guchar *srcthis, guchar *srcnext, guchar *dst,
gint width, gint bpp, gint filtno)
{
gint pf[9];
guchar *ip0, *ip1, *ip2, *or, *orend;
orend = dst + width * bpp;
ip0 = srclast;
ip1 = srcthis;
ip2 = srcnext;
for (or = dst; or < orend; ip0++, ip1++, ip2++, or++)
{
pf[0] = *ip1;
pf[1] = *(ip1 - bpp);
pf[2] = *(ip2 - bpp);
pf[3] = *(ip2);
pf[4] = *(ip2 + bpp);
pf[5] = *(ip1 + bpp);
pf[6] = *(ip0 + bpp);
pf[7] = *(ip0);
pf[8] = *(ip0 - bpp);
*or=(atfuncs[filtno])(pf);
}
}
/* We restrict radius to the values: 0.333333 <= radius <= 1.0 */
/* so that no fewer and no more than a 3x3 grid of pixels around */
/* the pixel in question needs to be read. Given this, we only */
/* need 3 or 4 weightings per hexagon, as follows: */
/* _ _ */
/* Vertical hex: |_|_| 1 2 */
/* |X|_| 0 3 */
/* _ */
/* _ _|_| 1 */
/* Middle hex: |_| 1 Horizontal hex: |X|_| 0 2 */
/* |X| 0 |_| 3 */
/* |_| 2 */
/* all filters */
gint V0[NOIVAL],V1[NOIVAL],V2[NOIVAL],V3[NOIVAL]; /* vertical hex */
gint M0[NOIVAL],M1[NOIVAL],M2[NOIVAL]; /* middle hex */
gint H0[NOIVAL],H1[NOIVAL],H2[NOIVAL],H3[NOIVAL]; /* horizontal hex */
/* alpha trimmed and edge enhancement only */
gint ALFRAC[NOIVAL * 8]; /* fractional alpha divider table */
/* optimal estimation only */
gint AVEDIV[7 * NOCSVAL]; /* divide by 7 to give average value */
gint SQUARE[2 * NOCSVAL]; /* scaled square lookup table */
/* Table initialisation function - return alpha range */
static gint
nlfiltInit (gdouble alpha, gdouble radius, FilterType filter)
{
gint alpharange; /* alpha range value 0 - 3 */
gdouble meanscale; /* scale for finding mean */
gdouble mmeanscale; /* scale for finding mean - midle hex */
gdouble alphafraction; /* fraction of next largest/smallest
* to subtract from sum
*/
switch (filter)
{
case filter_alpha_trim:
{
gdouble noinmean;
/* alpha only makes sense in range 0.0 - 0.5 */
alpha /= 2.0;
/* number of elements (out of a possible 7) used in the mean */
noinmean = ((0.5 - alpha) * 12.0) + 1.0;
mmeanscale = meanscale = 1.0/noinmean;
if (alpha == 0.0) { /* mean filter */
alpharange = 0;
alphafraction = 0.0; /* not used */
} else if (alpha < (1.0/6.0)) { /* mean of 5 to 7 middle values */
alpharange = 1;
alphafraction = (7.0 - noinmean)/2.0;
} else if (alpha < (1.0/3.0)) { /* mean of 3 to 5 middle values */
alpharange = 2;
alphafraction = (5.0 - noinmean)/2.0;
} else { /* mean of 1 to 3 middle values */
/* alpha==0.5 => median filter */
alpharange = 3;
alphafraction = (3.0 - noinmean)/2.0;
}
}
break;
case filter_opt_est: {
gint i;
gdouble noinmean = 7.0;
/* edge enhancement function */
alpharange = 5;
/* compute scaled hex values */
mmeanscale=meanscale=1.0;
/* Set up 1:1 division lookup - not used */
alphafraction=1.0/noinmean;
/* estimate of noise variance */
noisevariance = alpha * (gdouble)255;
noisevariance = noisevariance * noisevariance / 8.0;
/* set yp optimal estimation specific stuff */
for (i=0;i<(7*NOCSVAL);i++) { /* divide scaled value by 7 lookup */
AVEDIV[i] = CSCTOSC(i)/7; /* scaled divide by 7 */
}
/* compute square and rescale by
* (val >> (2 * SCALEB + 2)) table
*/
for (i=0;i<(2*NOCSVAL);i++) {
gint val;
/* NOCSVAL offset to cope with -ve input values */
val = CSCTOSC(i - NOCSVAL);
SQUARE[i] = (val * val) >> (2 * SCALEB + 2);
}
}
break;
case filter_edge_enhance: {
if (alpha == 1.0) alpha = 0.99;
alpharange = 4;
/* mean of 7 and scaled by -alpha/(1-alpha) */
meanscale = 1.0 * (-alpha/((1.0 - alpha) * 7.0));
/* middle pixel has 1/(1-alpha) as well */
mmeanscale = 1.0 * (1.0/(1.0 - alpha) + meanscale);
alphafraction = 0.0; /* not used */
}
break;
default:
g_printerr ("unknown filter %d\n", filter);
return -1;
}
/*
* Setup pixel weighting tables -
* note we pre-compute mean division here too.
*/
{
gint i;
gdouble hexhoff,hexvoff;
gdouble tabscale,mtabscale;
gdouble v0,v1,v2,v3,m0,m1,m2,h0,h1,h2,h3;
/* horizontal offset of vertical hex centers */
hexhoff = radius/2;
/* vertical offset of vertical hex centers */
hexvoff = 3.0 * radius/sqrt(12.0);
/*
* scale tables to normalise by hexagon
* area, and number of hexes used in mean
*/
tabscale = meanscale / (radius * hexvoff);
mtabscale = mmeanscale / (radius * hexvoff);
v0 = hex_area(0.0,0.0,hexhoff,hexvoff,radius) * tabscale;
v1 = hex_area(0.0,1.0,hexhoff,hexvoff,radius) * tabscale;
v2 = hex_area(1.0,1.0,hexhoff,hexvoff,radius) * tabscale;
v3 = hex_area(1.0,0.0,hexhoff,hexvoff,radius) * tabscale;
m0 = hex_area(0.0,0.0,0.0,0.0,radius) * mtabscale;
m1 = hex_area(0.0,1.0,0.0,0.0,radius) * mtabscale;
m2 = hex_area(0.0,-1.0,0.0,0.0,radius) * mtabscale;
h0 = hex_area(0.0,0.0,radius,0.0,radius) * tabscale;
h1 = hex_area(1.0,1.0,radius,0.0,radius) * tabscale;
h2 = hex_area(1.0,0.0,radius,0.0,radius) * tabscale;
h3 = hex_area(1.0,-1.0,radius,0.0,radius) * tabscale;
for (i=0; i <= MXIVAL; i++) {
gdouble fi;
fi = (gdouble)i;
V0[i] = SROUND(fi * v0);
V1[i] = SROUND(fi * v1);
V2[i] = SROUND(fi * v2);
V3[i] = SROUND(fi * v3);
M0[i] = SROUND(fi * m0);
M1[i] = SROUND(fi * m1);
M2[i] = SROUND(fi * m2);
H0[i] = SROUND(fi * h0);
H1[i] = SROUND(fi * h1);
H2[i] = SROUND(fi * h2);
H3[i] = SROUND(fi * h3);
}
/* set up alpha fraction lookup table used on big/small */
for (i=0; i < (NOIVAL * 8); i++) {
ALFRAC[i] = SROUND((gdouble)i * alphafraction);
}
}
return alpharange;
}
/* Core pixel processing function - hand it 3x3 pixels and return result. */
/* Mean filter */
static gint
atfilt0(gint32 *p)
{
gint retv;
/* map to scaled hexagon values */
retv = M0[p[0]] + M1[p[3]] + M2[p[7]];
retv += H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
retv += V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
retv += V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
retv += H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
retv += V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
retv += V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
return UNSCALE(retv);
}
/* Mean of 5 - 7 middle values */
static gint
atfilt1 (gint32 *p)
{
gint h0,h1,h2,h3,h4,h5,h6; /* hexagon values 2 3 */
/* 1 0 4 */
/* 6 5 */
gint big,small;
/* map to scaled hexagon values */
h0 = M0[p[0]] + M1[p[3]] + M2[p[7]];
h1 = H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
h2 = V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
h3 = V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
h4 = H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
h5 = V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
h6 = V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
/* sum values and also discover the largest and smallest */
big = small = h0;
#define CHECK(xx) \
h0 += xx; \
if (xx > big) \
big = xx; \
else if (xx < small) \
small = xx;
CHECK(h1)
CHECK(h2)
CHECK(h3)
CHECK(h4)
CHECK(h5)
CHECK(h6)
#undef CHECK
/* Compute mean of middle 5-7 values */
return UNSCALE(h0 -ALFRAC[(big + small)>>SCALEB]);
}
/* Mean of 3 - 5 middle values */
static gint
atfilt2 (gint32 *p)
{
gint h0,h1,h2,h3,h4,h5,h6; /* hexagon values 2 3 */
/* 1 0 4 */
/* 6 5 */
gint big0,big1,small0,small1;
/* map to scaled hexagon values */
h0 = M0[p[0]] + M1[p[3]] + M2[p[7]];
h1 = H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
h2 = V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
h3 = V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
h4 = H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
h5 = V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
h6 = V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
/* sum values and also discover the 2 largest and 2 smallest */
big0 = small0 = h0;
small1 = G_MAXINT;
big1 = 0;
#define CHECK(xx) \
h0 += xx; \
if (xx > big1) \
{ \
if (xx > big0) \
{ \
big1 = big0; \
big0 = xx; \
} \
else \
big1 = xx; \
} \
if (xx < small1) \
{ \
if (xx < small0) \
{ \
small1 = small0; \
small0 = xx; \
} \
else \
small1 = xx; \
}
CHECK(h1)
CHECK(h2)
CHECK(h3)
CHECK(h4)
CHECK(h5)
CHECK(h6)
#undef CHECK
/* Compute mean of middle 3-5 values */
return UNSCALE(h0 -big0 -small0 -ALFRAC[(big1 + small1)>>SCALEB]);
}
/*
* Mean of 1 - 3 middle values.
* If only 1 value, then this is a median filter.
*/
static gint32
atfilt3(gint32 *p)
{
gint h0,h1,h2,h3,h4,h5,h6; /* hexagon values 2 3 */
/* 1 0 4 */
/* 6 5 */
gint big0,big1,big2,small0,small1,small2;
/* map to scaled hexagon values */
h0 = M0[p[0]] + M1[p[3]] + M2[p[7]];
h1 = H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
h2 = V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
h3 = V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
h4 = H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
h5 = V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
h6 = V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
/* sum values and also discover the 3 largest and 3 smallest */
big0 = small0 = h0;
small1 = small2 = G_MAXINT;
big1 = big2 = 0;
#define CHECK(xx) \
h0 += xx; \
if (xx > big2) \
{ \
if (xx > big1) \
{ \
if (xx > big0) \
{ \
big2 = big1; \
big1 = big0; \
big0 = xx; \
} \
else \
{ \
big2 = big1; \
big1 = xx; \
} \
} \
else \
big2 = xx; \
} \
if (xx < small2) \
{ \
if (xx < small1) \
{ \
if (xx < small0) \
{ \
small2 = small1; \
small1 = small0; \
small0 = xx; \
} \
else \
{ \
small2 = small1; \
small1 = xx; \
} \
} \
else \
small2 = xx; \
}
CHECK(h1)
CHECK(h2)
CHECK(h3)
CHECK(h4)
CHECK(h5)
CHECK(h6)
#undef CHECK
/* Compute mean of middle 1-3 values */
return UNSCALE(h0-big0-big1-small0-small1-ALFRAC[(big2+small2)>>SCALEB]);
}
/* Edge enhancement */
static gint
atfilt4 (gint *p)
{
gint hav;
/* map to scaled hexagon values and compute enhance value */
hav = M0[p[0]] + M1[p[3]] + M2[p[7]];
hav += H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
hav += V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
hav += V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
hav += H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
hav += V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
hav += V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
if (hav < 0)
hav = 0;
hav = UNSCALE(hav);
if (hav > (gdouble)255)
hav = (gdouble)255;
return hav;
}
/* Optimal estimation - do smoothing in inverse proportion */
/* to the local variance. */
/* notice we use the globals noisevariance */
gint
atfilt5(gint *p) {
gint mean,variance,temp;
gint h0,h1,h2,h3,h4,h5,h6; /* hexagon values 2 3 */
/* 1 0 4 */
/* 6 5 */
/* map to scaled hexagon values */
h0 = M0[p[0]] + M1[p[3]] + M2[p[7]];
h1 = H0[p[0]] + H1[p[2]] + H2[p[1]] + H3[p[8]];
h2 = V0[p[0]] + V1[p[3]] + V2[p[2]] + V3[p[1]];
h3 = V0[p[0]] + V1[p[3]] + V2[p[4]] + V3[p[5]];
h4 = H0[p[0]] + H1[p[4]] + H2[p[5]] + H3[p[6]];
h5 = V0[p[0]] + V1[p[7]] + V2[p[6]] + V3[p[5]];
h6 = V0[p[0]] + V1[p[7]] + V2[p[8]] + V3[p[1]];
mean = h0 + h1 + h2 + h3 + h4 + h5 + h6;
/* compute scaled mean by dividing by 7 */
mean = AVEDIV[SCTOCSC(mean)];
/* compute scaled variance */
temp = (h1 - mean); variance = SQUARE[NOCSVAL + SCTOCSC(temp)];
/* and rescale to keep */
temp = (h2 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
/* within 32 bit limits */
temp = (h3 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
temp = (h4 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
temp = (h5 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
temp = (h6 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
/* (temp = h0 - mean) */
temp = (h0 - mean); variance += SQUARE[NOCSVAL + SCTOCSC(temp)];
if (variance != 0) /* avoid possible divide by 0 */
/* optimal estimate */
temp = mean + (variance * temp) / (variance + noisevariance);
else temp = h0;
if (temp < 0)
temp = 0;
temp = RUNSCALE(temp);
if (temp > (gdouble)255) temp = (gdouble)255;
return temp;
}
/* Triangle orientation is per geometric axes (not graphical axies) */
#define NW 0 /* North west triangle /| */
#define NE 1 /* North east triangle |\ */
#define SW 2 /* South west triangle \| */
#define SE 3 /* South east triangle |/ */
#define STH 2
#define EST 1
#define SWAPI(a,b) (t = a, a = -b, b = -t)
/* compute the area of overlap of a hexagon diameter d, */
/* centered at hx,hy, with a unit square of center sx,sy. */
static gdouble
hex_area (gdouble sx, gdouble sy, gdouble hx, gdouble hy, gdouble d)
{
gdouble hx0,hx1,hx2,hy0,hy1,hy2,hy3;
gdouble sx0,sx1,sy0,sy1;
/* compute square coordinates */
sx0 = sx - 0.5;
sy0 = sy - 0.5;
sx1 = sx + 0.5;
sy1 = sy + 0.5;
/* compute hexagon coordinates */
hx0 = hx - d/2.0;
hx1 = hx;
hx2 = hx + d/2.0;
hy0 = hy - 0.5773502692 * d; /* d / sqrt(3) */
hy1 = hy - 0.2886751346 * d; /* d / sqrt(12) */
hy2 = hy + 0.2886751346 * d; /* d / sqrt(12) */
hy3 = hy + 0.5773502692 * d; /* d / sqrt(3) */
return
triang_area(sx0,sy0,sx1,sy1,hx0,hy2,hx1,hy3,NW) +
triang_area(sx0,sy0,sx1,sy1,hx1,hy2,hx2,hy3,NE) +
rectang_area(sx0,sy0,sx1,sy1,hx0,hy1,hx2,hy2) +
triang_area(sx0,sy0,sx1,sy1,hx0,hy0,hx1,hy1,SW) +
triang_area(sx0,sy0,sx1,sy1,hx1,hy0,hx2,hy1,SE);
}
static gdouble
triang_area (gdouble rx0, gdouble ry0, gdouble rx1, gdouble ry1, gdouble tx0,
gdouble ty0, gdouble tx1, gdouble ty1, gint tt)
{
gdouble a,b,c,d;
gdouble lx0,ly0,lx1,ly1;
/* Convert everything to a NW triangle */
if (tt & STH) {
gdouble t;
SWAPI(ry0,ry1);
SWAPI(ty0,ty1);
} if (tt & EST) {
gdouble t;
SWAPI(rx0,rx1);
SWAPI(tx0,tx1);
}
/* Compute overlapping box */
if (tx0 > rx0)
rx0 = tx0;
if (ty0 > ry0)
ry0 = ty0;
if (tx1 < rx1)
rx1 = tx1;
if (ty1 < ry1)
ry1 = ty1;
if (rx1 <= rx0 || ry1 <= ry0)
return 0.0;
/* Need to compute diagonal line intersection with the box */
/* First compute co-efficients to formulas x = a + by and y = c + dx */
b = (tx1 - tx0)/(ty1 - ty0);
a = tx0 - b * ty0;
d = (ty1 - ty0)/(tx1 - tx0);
c = ty0 - d * tx0;
/* compute top or right intersection */
tt = 0;
ly1 = ry1;
lx1 = a + b * ly1;
if (lx1 <= rx0)
return (rx1 - rx0) * (ry1 - ry0);
else if (lx1 > rx1) { /* could be right hand side */
lx1 = rx1;
ly1 = c + d * lx1;
if (ly1 <= ry0)
return (rx1 - rx0) * (ry1 - ry0);
tt = 1; /* right hand side intersection */
}
/* compute left or bottom intersection */
lx0 = rx0;
ly0 = c + d * lx0;
if (ly0 >= ry1)
return (rx1 - rx0) * (ry1 - ry0);
else if (ly0 < ry0) { /* could be right hand side */
ly0 = ry0;
lx0 = a + b * ly0;
if (lx0 >= rx1)
return (rx1 - rx0) * (ry1 - ry0);
tt |= 2; /* bottom intersection */
}
if (tt == 0) { /* top and left intersection */
/* rectangle minus triangle */
return ((rx1 - rx0) * (ry1 - ry0))
- (0.5 * (lx1 - rx0) * (ry1 - ly0));
}
else if (tt == 1) { /* right and left intersection */
return ((rx1 - rx0) * (ly0 - ry0))
+ (0.5 * (rx1 - rx0) * (ly1 - ly0));
} else if (tt == 2) { /* top and bottom intersection */
return ((rx1 - lx1) * (ry1 - ry0))
+ (0.5 * (lx1 - lx0) * (ry1 - ry0));
} else { /* tt == 3 */ /* right and bottom intersection */
/* triangle */
return (0.5 * (rx1 - lx0) * (ly1 - ry0));
}
}
/* Compute rectangle area */
static gdouble
rectang_area (gdouble rx0, gdouble ry0, gdouble rx1, gdouble ry1, gdouble tx0,
gdouble ty0, gdouble tx1, gdouble ty1)
{
/* Compute overlapping box */
if (tx0 > rx0)
rx0 = tx0;
if (ty0 > ry0)
ry0 = ty0;
if (tx1 < rx1)
rx1 = tx1;
if (ty1 < ry1)
ry1 = ty1;
if (rx1 <= rx0 || ry1 <= ry0)
return 0.0;
return (rx1 - rx0) * (ry1 - ry0);
}
static void
nlfilter (GObject *config,
GimpDrawable *drawable,
GimpPreview *preview)
{
GeglBuffer *src_buffer;
GeglBuffer *dest_buffer;
const Babl *format;
guchar *srcbuf, *dstbuf;
guchar *lastrow, *thisrow, *nextrow, *temprow;
gint x1, y1, y2;
gint width, height, bpp;
gint filtno, y, rowsize, exrowsize, p_update;
gdouble alpha;
gdouble radius;
gint filter;
g_object_get (config,
"alpha", &alpha,
"radius", &radius,
NULL);
filter = gimp_procedure_config_get_choice_id (GIMP_PROCEDURE_CONFIG (config),
"filter");
if (preview)
{
gimp_preview_get_position (preview, &x1, &y1);
gimp_preview_get_size (preview, &width, &height);
y2 = y1 + height;
}
else
{
if (! gimp_drawable_mask_intersect (drawable,
&x1, &y1, &width, &height))
return;
y2 = y1 + height;
}
if (gimp_drawable_has_alpha (drawable))
format = babl_format ("R'G'B'A u8");
else
format = babl_format ("R'G'B' u8");
src_buffer = gimp_drawable_get_buffer (drawable);
if (preview)
dest_buffer = gegl_buffer_new (gegl_buffer_get_extent (src_buffer), format);
else
dest_buffer = gimp_drawable_get_shadow_buffer (drawable);
bpp = babl_format_get_bytes_per_pixel (format);
rowsize = width * bpp;
exrowsize = (width + 2) * bpp;
p_update = width / 20 + 1;
/* source buffer gives one pixel margin all around destination buffer */
srcbuf = g_new0 (guchar, exrowsize * 3);
dstbuf = g_new0 (guchar, rowsize);
/* pointers to second pixel in each source row */
lastrow = srcbuf + bpp;
thisrow = lastrow + exrowsize;
nextrow = thisrow + exrowsize;
filtno = nlfiltInit (alpha, radius, filter);
if (!preview)
gimp_progress_init (_("NL Filter"));
/* first row */
gegl_buffer_get (src_buffer, GEGL_RECTANGLE (x1, y1, width, 1), 1.0,
format, thisrow,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
/* copy thisrow[0] to thisrow[-1], thisrow[width-1] to thisrow[width] */
memcpy (thisrow - bpp, thisrow, bpp);
memcpy (thisrow + rowsize, thisrow + rowsize - bpp, bpp);
/* copy whole thisrow to lastrow */
memcpy (lastrow - bpp, thisrow - bpp, exrowsize);
for (y = y1; y < y2 - 1; y++)
{
if (((y % p_update) == 0) && !preview)
gimp_progress_update ((gdouble) y / (gdouble) height);
gegl_buffer_get (src_buffer, GEGL_RECTANGLE (x1, y + 1, width, 1), 1.0,
format, nextrow,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
memcpy (nextrow - bpp, nextrow, bpp);
memcpy (nextrow + rowsize, nextrow + rowsize - bpp, bpp);
nlfiltRow (lastrow, thisrow, nextrow, dstbuf, width, bpp, filtno);
gegl_buffer_set (dest_buffer, GEGL_RECTANGLE (x1, y, width, 1), 0,
format, dstbuf,
GEGL_AUTO_ROWSTRIDE);
/* rotate row buffers */
temprow = lastrow; lastrow = thisrow;
thisrow = nextrow; nextrow = temprow;
}
/* last row */
memcpy (nextrow - bpp, thisrow - bpp, exrowsize);
nlfiltRow (lastrow, thisrow, nextrow, dstbuf, width, bpp, filtno);
gegl_buffer_set (dest_buffer, GEGL_RECTANGLE (x1, y2 - 1, width, 1), 0,
format, dstbuf,
GEGL_AUTO_ROWSTRIDE);
g_free (srcbuf);
g_free (dstbuf);
if (preview)
{
guchar *buf = g_new (guchar, width * height * bpp);
gegl_buffer_get (dest_buffer, GEGL_RECTANGLE (x1, y1, width, height), 1.0,
format, buf,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
gimp_preview_draw_buffer (GIMP_PREVIEW (preview), buf, width * bpp);
g_free (buf);
}
g_object_unref (src_buffer);
g_object_unref (dest_buffer);
if (! preview)
{
gimp_progress_update (1.0);
gimp_drawable_merge_shadow (drawable, TRUE);
gimp_drawable_update (drawable, x1, y1, width, height);
gimp_displays_flush ();
}
}
static void
nlfilter_preview (GtkWidget *widget,
GObject *config)
{
GimpPreview *preview = GIMP_PREVIEW (widget);
GimpDrawable *drawable = g_object_get_data (config, "drawable");
nlfilter (config, drawable, preview);
}
static gboolean
nlfilter_dialog (GimpProcedure *procedure,
GObject *config,
GimpDrawable *drawable)
{
GtkWidget *dialog;
GtkWidget *preview;
GtkWidget *frame;
GtkWidget *scale;
gboolean run;
gimp_ui_init (PLUG_IN_BINARY);
dialog = gimp_procedure_dialog_new (procedure,
GIMP_PROCEDURE_CONFIG (config),
_("NL Filter"));
frame = gimp_procedure_dialog_get_widget (GIMP_PROCEDURE_DIALOG (dialog),
"filter", GIMP_TYPE_INT_RADIO_FRAME);
gtk_widget_set_margin_bottom (frame, 12);
scale = gimp_procedure_dialog_get_scale_entry (GIMP_PROCEDURE_DIALOG (dialog),
"alpha", 1.0);
gtk_widget_set_margin_bottom (scale, 12);
scale = gimp_procedure_dialog_get_scale_entry (GIMP_PROCEDURE_DIALOG (dialog),
"radius", 1.0);
gtk_widget_set_margin_bottom (scale, 12);
gimp_procedure_dialog_fill_box (GIMP_PROCEDURE_DIALOG (dialog),
"nlfilter-vbox", "filter", "alpha",
"radius", NULL);
preview = gimp_procedure_dialog_get_drawable_preview (GIMP_PROCEDURE_DIALOG (dialog),
"preview", drawable);
gtk_widget_set_margin_bottom (preview, 12);
g_object_set_data (config, "drawable", drawable);
g_signal_connect (preview, "invalidated",
G_CALLBACK (nlfilter_preview),
config);
g_signal_connect_swapped (config, "notify",
G_CALLBACK (gimp_preview_invalidate),
preview);
gimp_procedure_dialog_fill (GIMP_PROCEDURE_DIALOG (dialog),
"preview", "nlfilter-vbox", NULL);
gtk_widget_show (dialog);
run = gimp_procedure_dialog_run (GIMP_PROCEDURE_DIALOG (dialog));
gtk_widget_destroy (dialog);
return run;
}