/*
* PIKA - Photo and Image Kooker Application
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 .
*/
/*
* hot.c - Scan an image for pixels with RGB values that will give
* "unsafe" values of chrominance signal or composite signal
* amplitude when encoded into an NTSC or PAL color signal.
* (This happens for certain high-intensity high-saturation colors
* that are rare in real scenes, but can easily be present
* in synthetic images.)
*
* Such pixels can be flagged so the user may then choose other
* colors. Or, the offending pixels can be made "safe"
* in a manner that preserves hue.
*
* There are two reasonable ways to make a pixel "safe":
* We can reduce its intensity (luminance) while leaving
* hue and saturation the same. Or, we can reduce saturation
* while leaving hue and luminance the same. A #define selects
* which strategy to use.
*
* Note to the user: You must add your own read_pixel() and write_pixel()
* routines. You may have to modify pix_decode() and pix_encode().
* MAXPIX, WID, and HGT are likely to need modification.
*/
/*
* Originally written as "ikNTSC.c" by Alan Wm Paeth,
* University of Waterloo, August, 1985
* Updated by Dave Martindale, Imax Systems Corp., December 1990
*/
/*
* Compile time options:
*
*
* CHROMA_LIM is the limit (in IRE units) of the overall
* chrominance amplitude; it should be 50 or perhaps
* very slightly higher.
*
* COMPOS_LIM is the maximum amplitude (in IRE units) allowed for
* the composite signal. A value of 100 is the maximum
* monochrome white, and is always safe. 120 is the absolute
* limit for NTSC broadcasting, since the transmitter's carrier
* goes to zero with 120 IRE input signal. Generally, 110
* is a good compromise - it allows somewhat brighter colors
* than 100, while staying safely away from the hard limit.
*/
#include "config.h"
#include
#include
#include
#include "libpika/stdplugins-intl.h"
#define PLUG_IN_PROC "plug-in-hot"
#define PLUG_IN_BINARY "hot"
#define PLUG_IN_ROLE "pika-hot"
typedef enum
{
ACT_LREDUX,
ACT_SREDUX,
ACT_FLAG
} hotAction;
typedef enum
{
MODE_NTSC,
MODE_PAL
} hotModes;
#define CHROMA_LIM 50.0 /* chroma amplitude limit */
#define COMPOS_LIM 110.0 /* max IRE amplitude */
/*
* RGB to YIQ encoding matrix.
*/
struct
{
gdouble pedestal;
gdouble gamma;
gdouble code[3][3];
}
static mode_vals[2] =
{
{
7.5,
2.2,
{
{ 0.2989, 0.5866, 0.1144 },
{ 0.5959, -0.2741, -0.3218 },
{ 0.2113, -0.5227, 0.3113 }
}
},
{
0.0,
2.8,
{
{ 0.2989, 0.5866, 0.1144 },
{ -0.1473, -0.2891, 0.4364 },
{ 0.6149, -0.5145, -0.1004 }
}
}
};
#define SCALE 8192 /* scale factor: do floats with int math */
#define MAXPIX 255 /* white value */
typedef struct _Hot Hot;
typedef struct _HotClass HotClass;
struct _Hot
{
PikaPlugIn parent_instance;
};
struct _HotClass
{
PikaPlugInClass parent_class;
};
#define HOT_TYPE (hot_get_type ())
#define HOT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), HOT_TYPE, Hot))
GType hot_get_type (void) G_GNUC_CONST;
static GList * hot_query_procedures (PikaPlugIn *plug_in);
static PikaProcedure * hot_create_procedure (PikaPlugIn *plug_in,
const gchar *name);
static PikaValueArray * hot_run (PikaProcedure *procedure,
PikaRunMode run_mode,
PikaImage *image,
gint n_drawables,
PikaDrawable **drawables,
PikaProcedureConfig *config,
gpointer run_data);
static gboolean pluginCore (PikaImage *image,
PikaDrawable *drawable,
GObject *config);
static gboolean plugin_dialog (PikaProcedure *procedure,
GObject *config);
static gboolean hotp (guint8 r,
guint8 g,
guint8 b);
static void build_tab (gint m);
/*
* gc: apply the gamma correction specified for this video standard.
* inv_gc: inverse function of gc.
*
* These are generally just a call to pow(), but be careful!
* Future standards may use more complex functions.
* (e.g. SMPTE 240M's "electro-optic transfer characteristic").
*/
#define gc(x,m) pow(x, 1.0 / mode_vals[m].gamma)
#define inv_gc(x,m) pow(x, mode_vals[m].gamma)
/*
* pix_decode: decode an integer pixel value into a floating-point
* intensity in the range [0, 1].
*
* pix_encode: encode a floating-point intensity into an integer
* pixel value.
*
* The code given here assumes simple linear encoding; you must change
* these routines if you use a different pixel encoding technique.
*/
#define pix_decode(v) ((double)v / (double)MAXPIX)
#define pix_encode(v) ((int)(v * (double)MAXPIX + 0.5))
G_DEFINE_TYPE (Hot, hot, PIKA_TYPE_PLUG_IN)
PIKA_MAIN (HOT_TYPE)
DEFINE_STD_SET_I18N
static gint tab[3][3][MAXPIX+1]; /* multiply lookup table */
static gdouble chroma_lim; /* chroma limit */
static gdouble compos_lim; /* composite amplitude limit */
static glong ichroma_lim2; /* chroma limit squared (scaled integer) */
static gint icompos_lim; /* composite amplitude limit (scaled integer) */
static void
hot_class_init (HotClass *klass)
{
PikaPlugInClass *plug_in_class = PIKA_PLUG_IN_CLASS (klass);
plug_in_class->query_procedures = hot_query_procedures;
plug_in_class->create_procedure = hot_create_procedure;
plug_in_class->set_i18n = STD_SET_I18N;
}
static void
hot_init (Hot *hot)
{
}
static GList *
hot_query_procedures (PikaPlugIn *plug_in)
{
return g_list_append (NULL, g_strdup (PLUG_IN_PROC));
}
static PikaProcedure *
hot_create_procedure (PikaPlugIn *plug_in,
const gchar *name)
{
PikaProcedure *procedure = NULL;
if (! strcmp (name, PLUG_IN_PROC))
{
procedure = pika_image_procedure_new (plug_in, name,
PIKA_PDB_PROC_TYPE_PLUGIN,
hot_run, NULL, NULL);
pika_procedure_set_image_types (procedure, "RGB");
pika_procedure_set_sensitivity_mask (procedure,
PIKA_PROCEDURE_SENSITIVE_DRAWABLE);
pika_procedure_set_menu_label (procedure, _("_Hot..."));
pika_procedure_add_menu_path (procedure, "/Colors/[Modify]");
pika_procedure_set_documentation (procedure,
_("Find and fix pixels that may "
"be unsafely bright"),
"hot scans an image for pixels that "
"will give unsave values of "
"chrominance or composite signale "
"amplitude when encoded into an NTSC "
"or PAL signal. Three actions can be "
"performed on these 'hot' pixels. "
"(0) reduce luminance, "
"(1) reduce saturation, or (2) Blacken.",
name);
pika_procedure_set_attribution (procedure,
"Eric L. Hernes, Alan Wm Paeth",
"Eric L. Hernes",
"1997");
PIKA_PROC_ARG_INT (procedure, "mode",
_("Mode"),
"Mode { NTSC (0), PAL (1) }",
0, 1, MODE_NTSC,
G_PARAM_READWRITE);
PIKA_PROC_ARG_INT (procedure, "action",
_("Action"),
"Action { (0) reduce luminance, "
"(1) reduce saturation, or (2) Blacken }",
0, 2, ACT_LREDUX,
G_PARAM_READWRITE);
PIKA_PROC_ARG_BOOLEAN (procedure, "new-layer",
_("Create _new layer"),
"Create a new layer",
TRUE,
G_PARAM_READWRITE);
}
return procedure;
}
static PikaValueArray *
hot_run (PikaProcedure *procedure,
PikaRunMode run_mode,
PikaImage *image,
gint n_drawables,
PikaDrawable **drawables,
PikaProcedureConfig *config,
gpointer run_data)
{
PikaDrawable *drawable;
gegl_init (NULL, NULL);
if (n_drawables != 1)
{
GError *error = NULL;
g_set_error (&error, PIKA_PLUG_IN_ERROR, 0,
_("Procedure '%s' only works with one drawable."),
pika_procedure_get_name (procedure));
return pika_procedure_new_return_values (procedure,
PIKA_PDB_CALLING_ERROR,
error);
}
else
{
drawable = drawables[0];
}
if (run_mode == PIKA_RUN_INTERACTIVE && ! plugin_dialog (procedure, G_OBJECT (config)))
return pika_procedure_new_return_values (procedure,
PIKA_PDB_CANCEL,
NULL);
if (! pluginCore (image, drawable, G_OBJECT (config)))
return pika_procedure_new_return_values (procedure,
PIKA_PDB_EXECUTION_ERROR,
NULL);
if (run_mode != PIKA_RUN_NONINTERACTIVE)
pika_displays_flush ();
return pika_procedure_new_return_values (procedure, PIKA_PDB_SUCCESS, NULL);
}
static gboolean
pluginCore (PikaImage *image,
PikaDrawable *drawable,
GObject *config)
{
gint mode;
gint action;
gboolean new_layer;
GeglBuffer *src_buffer;
GeglBuffer *dest_buffer;
const Babl *src_format;
const Babl *dest_format;
gint src_bpp;
gint dest_bpp;
gboolean success = TRUE;
PikaLayer *nl = NULL;
gint y, i;
gint Y, I, Q;
gint width, height;
gint sel_x1, sel_x2, sel_y1, sel_y2;
gint prog_interval;
guchar *src, *s, *dst, *d;
guchar r, prev_r=0, new_r=0;
guchar g, prev_g=0, new_g=0;
guchar b, prev_b=0, new_b=0;
gdouble fy, fc, t, scale;
gdouble pr, pg, pb;
gdouble py;
g_object_get (config,
"mode", &mode,
"action", &action,
"new-layer", &new_layer,
NULL);
width = pika_drawable_get_width (drawable);
height = pika_drawable_get_height (drawable);
if (pika_drawable_has_alpha (drawable))
src_format = babl_format ("R'G'B'A u8");
else
src_format = babl_format ("R'G'B' u8");
dest_format = src_format;
if (new_layer)
{
gchar name[40];
const gchar *mode_names[] =
{
"ntsc",
"pal",
};
const gchar *action_names[] =
{
"lum redux",
"sat redux",
"flag",
};
g_snprintf (name, sizeof (name), "hot mask (%s, %s)",
mode_names[mode],
action_names[action]);
nl = pika_layer_new (image, name, width, height,
PIKA_RGBA_IMAGE,
100,
pika_image_get_default_new_layer_mode (image));
pika_drawable_fill (PIKA_DRAWABLE (nl), PIKA_FILL_TRANSPARENT);
pika_image_insert_layer (image, nl, NULL, 0);
dest_format = babl_format ("R'G'B'A u8");
}
if (! pika_drawable_mask_intersect (drawable,
&sel_x1, &sel_y1, &width, &height))
return success;
src_bpp = babl_format_get_bytes_per_pixel (src_format);
dest_bpp = babl_format_get_bytes_per_pixel (dest_format);
sel_x2 = sel_x1 + width;
sel_y2 = sel_y1 + height;
src = g_new (guchar, width * height * src_bpp);
dst = g_new (guchar, width * height * dest_bpp);
src_buffer = pika_drawable_get_buffer (drawable);
if (new_layer)
{
dest_buffer = pika_drawable_get_buffer (PIKA_DRAWABLE (nl));
}
else
{
dest_buffer = pika_drawable_get_shadow_buffer (drawable);
}
gegl_buffer_get (src_buffer,
GEGL_RECTANGLE (sel_x1, sel_y1, width, height), 1.0,
src_format, src,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
s = src;
d = dst;
build_tab (mode);
pika_progress_init (_("Hot"));
prog_interval = height / 10;
for (y = sel_y1; y < sel_y2; y++)
{
gint x;
if (y % prog_interval == 0)
pika_progress_update ((double) y / (double) (sel_y2 - sel_y1));
for (x = sel_x1; x < sel_x2; x++)
{
if (hotp (r = *(s + 0), g = *(s + 1), b = *(s + 2)))
{
if (action == ACT_FLAG)
{
for (i = 0; i < 3; i++)
*d++ = 0;
s += 3;
if (src_bpp == 4)
*d++ = *s++;
else if (new_layer)
*d++ = 255;
}
else
{
/*
* Optimization: cache the last-computed hot pixel.
*/
if (r == prev_r && g == prev_g && b == prev_b)
{
*d++ = new_r;
*d++ = new_g;
*d++ = new_b;
s += 3;
if (src_bpp == 4)
*d++ = *s++;
else if (new_layer)
*d++ = 255;
}
else
{
Y = tab[0][0][r] + tab[0][1][g] + tab[0][2][b];
I = tab[1][0][r] + tab[1][1][g] + tab[1][2][b];
Q = tab[2][0][r] + tab[2][1][g] + tab[2][2][b];
prev_r = r;
prev_g = g;
prev_b = b;
/*
* Get Y and chroma amplitudes in floating point.
*
* If your C library doesn't have hypot(), just use
* hypot(a,b) = sqrt(a*a, b*b);
*
* Then extract linear (un-gamma-corrected)
* floating-point pixel RGB values.
*/
fy = (double)Y / (double)SCALE;
fc = hypot ((double) I / (double) SCALE,
(double) Q / (double) SCALE);
pr = (double) pix_decode (r);
pg = (double) pix_decode (g);
pb = (double) pix_decode (b);
/*
* Reducing overall pixel intensity by scaling R,
* G, and B reduces Y, I, and Q by the same factor.
* This changes luminance but not saturation, since
* saturation is determined by the chroma/luminance
* ratio.
*
* On the other hand, by linearly interpolating
* between the original pixel value and a grey
* pixel with the same luminance (R=G=B=Y), we
* change saturation without affecting luminance.
*/
if (action == ACT_LREDUX)
{
/*
* Calculate a scale factor that will bring the pixel
* within both chroma and composite limits, if we scale
* luminance and chroma simultaneously.
*
* The calculated chrominance reduction applies
* to the gamma-corrected RGB values that are
* the input to the RGB-to-YIQ operation.
* Multiplying the original un-gamma-corrected
* pixel values by the scaling factor raised to
* the "gamma" power is equivalent, and avoids
* calling gc() and inv_gc() three times each. */
scale = chroma_lim / fc;
t = compos_lim / (fy + fc);
if (t < scale)
scale = t;
scale = pow (scale, mode_vals[mode].gamma);
r = (guint8) pix_encode (scale * pr);
g = (guint8) pix_encode (scale * pg);
b = (guint8) pix_encode (scale * pb);
}
else
{ /* ACT_SREDUX hopefully */
/*
* Calculate a scale factor that will bring the
* pixel within both chroma and composite
* limits, if we scale chroma while leaving
* luminance unchanged.
*
* We have to interpolate gamma-corrected RGB
* values, so we must convert from linear to
* gamma-corrected before interpolation and then
* back to linear afterwards.
*/
scale = chroma_lim / fc;
t = (compos_lim - fy) / fc;
if (t < scale)
scale = t;
pr = gc (pr, mode);
pg = gc (pg, mode);
pb = gc (pb, mode);
py = pr * mode_vals[mode].code[0][0] +
pg * mode_vals[mode].code[0][1] +
pb * mode_vals[mode].code[0][2];
r = pix_encode (inv_gc (py + scale * (pr - py),
mode));
g = pix_encode (inv_gc (py + scale * (pg - py),
mode));
b = pix_encode (inv_gc (py + scale * (pb - py),
mode));
}
*d++ = new_r = r;
*d++ = new_g = g;
*d++ = new_b = b;
s += 3;
if (src_bpp == 4)
*d++ = *s++;
else if (new_layer)
*d++ = 255;
}
}
}
else
{
if (! new_layer)
{
for (i = 0; i < src_bpp; i++)
*d++ = *s++;
}
else
{
s += src_bpp;
d += dest_bpp;
}
}
}
}
gegl_buffer_set (dest_buffer,
GEGL_RECTANGLE (sel_x1, sel_y1, width, height), 0,
dest_format, dst,
GEGL_AUTO_ROWSTRIDE);
pika_progress_update (1.0);
g_free (src);
g_free (dst);
g_object_unref (src_buffer);
g_object_unref (dest_buffer);
if (new_layer)
{
pika_drawable_update (PIKA_DRAWABLE (nl), sel_x1, sel_y1, width, height);
}
else
{
pika_drawable_merge_shadow (drawable, TRUE);
pika_drawable_update (drawable, sel_x1, sel_y1, width, height);
}
pika_displays_flush ();
return success;
}
static gboolean
plugin_dialog (PikaProcedure *procedure,
GObject *config)
{
GtkWidget *dlg;
GtkWidget *vbox;
GtkWidget *hbox;
GtkListStore *store;
gboolean run;
pika_ui_init (PLUG_IN_BINARY);
dlg = pika_procedure_dialog_new (procedure,
PIKA_PROCEDURE_CONFIG (config),
_("Hot"));
pika_dialog_set_alternative_button_order (GTK_DIALOG (dlg),
GTK_RESPONSE_OK,
GTK_RESPONSE_CANCEL,
-1);
pika_window_set_transient (GTK_WINDOW (dlg));
store = pika_int_store_new (_("N_TSC"), MODE_NTSC,
_("_PAL"), MODE_PAL,
NULL);
pika_procedure_dialog_get_int_radio (PIKA_PROCEDURE_DIALOG (dlg),
"mode", PIKA_INT_STORE (store));
store = pika_int_store_new (_("Reduce _Luminance"), ACT_LREDUX,
_("Reduce _Saturation"), ACT_SREDUX,
_("_Blacken"), ACT_FLAG,
NULL);
pika_procedure_dialog_get_int_radio (PIKA_PROCEDURE_DIALOG (dlg),
"action", PIKA_INT_STORE (store));
vbox = pika_procedure_dialog_fill_box (PIKA_PROCEDURE_DIALOG (dlg),
"hot-left-side",
"mode",
"new-layer",
NULL);
gtk_box_set_spacing (GTK_BOX (vbox), 12);
hbox = pika_procedure_dialog_fill_box (PIKA_PROCEDURE_DIALOG (dlg),
"hot-hbox",
"hot-left-side",
"action",
NULL);
gtk_box_set_spacing (GTK_BOX (hbox), 12);
gtk_box_set_homogeneous (GTK_BOX (hbox), TRUE);
gtk_widget_set_margin_bottom (hbox, 12);
gtk_orientable_set_orientation (GTK_ORIENTABLE (hbox),
GTK_ORIENTATION_HORIZONTAL);
pika_procedure_dialog_fill (PIKA_PROCEDURE_DIALOG (dlg),
"hot-hbox",
NULL);
gtk_widget_show (dlg);
run = pika_procedure_dialog_run (PIKA_PROCEDURE_DIALOG (dlg));
gtk_widget_destroy (dlg);
return run;
}
/*
* build_tab: Build multiply lookup table.
*
* For each possible pixel value, decode value into floating-point
* intensity. Then do gamma correction required by the video
* standard. Scale the result by our fixed-point scale factor.
* Then calculate 9 lookup table entries for this pixel value.
*
* We also calculate floating-point and scaled integer versions
* of our limits here. This prevents evaluating expressions every pixel
* when the compiler is too stupid to evaluate constant-valued
* floating-point expressions at compile time.
*
* For convenience, the limits are #defined using IRE units.
* We must convert them here into the units in which YIQ
* are measured. The conversion from IRE to internal units
* depends on the pedestal level in use, since as Y goes from
* 0 to 1, the signal goes from the pedestal level to 100 IRE.
* Chroma is always scaled to remain consistent with Y.
*/
static void
build_tab (int m)
{
double f;
int pv;
for (pv = 0; pv <= MAXPIX; pv++)
{
f = (double) SCALE * (double) gc ((double) pix_decode (pv), m);
tab[0][0][pv] = (int) (f * mode_vals[m].code[0][0] + 0.5);
tab[0][1][pv] = (int) (f * mode_vals[m].code[0][1] + 0.5);
tab[0][2][pv] = (int) (f * mode_vals[m].code[0][2] + 0.5);
tab[1][0][pv] = (int) (f * mode_vals[m].code[1][0] + 0.5);
tab[1][1][pv] = (int) (f * mode_vals[m].code[1][1] + 0.5);
tab[1][2][pv] = (int) (f * mode_vals[m].code[1][2] + 0.5);
tab[2][0][pv] = (int) (f * mode_vals[m].code[2][0] + 0.5);
tab[2][1][pv] = (int) (f * mode_vals[m].code[2][1] + 0.5);
tab[2][2][pv] = (int) (f * mode_vals[m].code[2][2] + 0.5);
}
chroma_lim = (double) CHROMA_LIM / (100.0 - mode_vals[m].pedestal);
compos_lim = ((double )COMPOS_LIM - mode_vals[m].pedestal) /
(100.0 - mode_vals[m].pedestal);
ichroma_lim2 = (int)(chroma_lim * SCALE + 0.5);
ichroma_lim2 *= ichroma_lim2;
icompos_lim = (int)(compos_lim * SCALE + 0.5);
}
static gboolean
hotp (guint8 r,
guint8 g,
guint8 b)
{
int y, i, q;
long y2, c2;
/*
* Pixel decoding, gamma correction, and matrix multiplication
* all done by lookup table.
*
* "i" and "q" are the two chrominance components;
* they are I and Q for NTSC.
* For PAL, "i" is U (scaled B-Y) and "q" is V (scaled R-Y).
* Since we only care about the length of the chroma vector,
* not its angle, we don't care which is which.
*/
y = tab[0][0][r] + tab[0][1][g] + tab[0][2][b];
i = tab[1][0][r] + tab[1][1][g] + tab[1][2][b];
q = tab[2][0][r] + tab[2][1][g] + tab[2][2][b];
/*
* Check to see if the chrominance vector is too long or the
* composite waveform amplitude is too large.
*
* Chrominance is too large if
*
* sqrt(i^2, q^2) > chroma_lim.
*
* The composite signal amplitude is too large if
*
* y + sqrt(i^2, q^2) > compos_lim.
*
* We avoid doing the sqrt by checking
*
* i^2 + q^2 > chroma_lim^2
* and
* y + sqrt(i^2 + q^2) > compos_lim
* sqrt(i^2 + q^2) > compos_lim - y
* i^2 + q^2 > (compos_lim - y)^2
*
*/
c2 = (long)i * i + (long)q * q;
y2 = (long)icompos_lim - y;
y2 *= y2;
if (c2 <= ichroma_lim2 && c2 <= y2)
{ /* no problems */
return FALSE;
}
return TRUE;
}