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im_stdif() -> a class 

also many bands support
This commit is contained in:
John Cupitt 2013-09-10 20:19:11 +01:00
parent f1c3e1a434
commit 96b3bf1fcb
9 changed files with 446 additions and 303 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
ChangeLog
View File

@ -4,9 +4,9 @@
INTERPRETATION_MATRIX etc.
- rewrite im_buildlut(), im_identity*(), im_maplut(), im_falsecolour(),
im_gammacorrect(), im_histgr(), im_histcum(), im_histnorm(), im_heq(),
im_histnD(), im_histindexed(), im_histspec(), im_invertlut(), im_lhisteq()
as classes
- vips_hist_local() does any number of bands
im_histnD(), im_histindexed(), im_histspec(), im_invertlut(), im_lhisteq(),
im_stdif() as classes
- vips_hist_local(), vips_stdif() do any number of bands
- thin vips8 wrapper for im_histplot()
- added vips_error_freeze() / vips_error_thaw()
- used freeze() / thaw() to stop file format sniffers logging spurious errors

24
libvips/deprecated/vips7compat.c
View File

@ -3445,6 +3445,30 @@ im_histgr( IMAGE *in, IMAGE *out, int bandno )
return( 0 );
}
int
im_stdif( IMAGE *in, IMAGE *out,
double a, double m0, double b, double s0,
int width, int height )
{
VipsImage *x;
if( vips_stdif( in, &x, width, height,
"a", a,
"b", b,
"m0", m0,
"s0", s0,
NULL ) )
return( -1 );
if( im_copy( x, out ) ) {
g_object_unref( x );
return( -1 );
}
g_object_unref( x );
return( 0 );
}
int
im_lhisteq( VipsImage *in, VipsImage *out, int width, int height )
{

2
libvips/histogram/Makefile.am
View File

@ -12,11 +12,11 @@ libhistogram_la_SOURCES = \
hist_plot.c \
hist_match.c \
hist_local.c \
stdif.c \
\
hist_dispatch.c \
im_mpercent.c \
im_project.c \
im_stdif.c \
tone.c
AM_CPPFLAGS = -I${top_srcdir}/libvips/include @VIPS_CFLAGS@ @VIPS_INCLUDES@

5
libvips/histogram/hist_local.c
View File

@ -243,11 +243,6 @@ vips_hist_local_build( VipsObject *object )
vips_error( class->nickname, "%s", _( "window too large" ) );
return( -1 );
}
if( local->width <= 0 ||
local->height <= 0 ) {
vips_error( class->nickname, "%s", _( "window too small" ) );
return( -1 );
}
/* Expand the input.
*/

2
libvips/histogram/histogram.c
View File

@ -239,6 +239,7 @@ vips_histogram_operation_init( void )
extern GType vips_hist_plot_get_type( void );
extern GType vips_hist_match_get_type( void );
extern GType vips_hist_local_get_type( void );
extern GType vips_stdif_get_type( void );
vips_maplut_get_type();
vips_hist_cum_get_type();
@ -247,4 +248,5 @@ vips_histogram_operation_init( void )
vips_hist_plot_get_type();
vips_hist_match_get_type();
vips_hist_local_get_type();
vips_stdif_get_type();
}

290
libvips/histogram/im_stdif.c
View File

@ -1,290 +0,0 @@
/* statistical difference
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 02/05/1990
* Modified on :
* 6/8/93 JC
* - now works for odd window sizes
* - ANSIfication
* 25/5/95 JC
* - new IM_ARRAY() macro
* 25/1/96 JC
* - im_lhisteq() adapted to make new im_stdif()
* - now partial, plus rolling window
* - 5x faster, amazingly
* - works
* 7/4/04
* - now uses im_embed() with edge stretching on the input, not
* the output
* 25/3/10
* - gtkdoc
* - small cleanups
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <vips/vips.h>
/* Hold global stuff here.
*/
typedef struct {
int xwin, ywin; /* Parameters */
double a, m0, b, s0;
} StdifInfo;
/* stdif generate function.
*/
static int
stdif_gen( REGION *or, void *seq, void *a, void *b )
{
REGION *ir = (REGION *) seq;
StdifInfo *inf = (StdifInfo *) b;
int npel = inf->xwin * inf->ywin;
Rect *r = &or->valid;
Rect irect;
int x, y, i, j;
int lsk;
int centre; /* Offset to move to centre of window */
/* What part of ir do we need?
*/
irect.left = or->valid.left;
irect.top = or->valid.top;
irect.width = or->valid.width + inf->xwin;
irect.height = or->valid.height + inf->ywin;
if( im_prepare( ir, &irect ) )
return( -1 );
lsk = IM_REGION_LSKIP( ir );
centre = lsk * (inf->ywin / 2) + inf->xwin / 2;
for( y = 0; y < r->height; y++ ) {
/* Get input and output pointers for this line.
*/
VipsPel *p = IM_REGION_ADDR( ir, r->left, r->top + y );
VipsPel *q = IM_REGION_ADDR( or, r->left, r->top + y );
/* Precompute some factors.
*/
double f1 = inf->a * inf->m0;
double f2 = 1.0 - inf->a;
double f3 = inf->b * inf->s0;
VipsPel *p1;
int sum;
int sum2;
/* Find sum, sum of squares for the start of this line.
*/
sum = 0;
sum2 = 0;
p1 = p;
for( j = 0; j < inf->ywin; j++ ) {
for( i = 0; i < inf->xwin; i++ ) {
int t = p1[i];
sum += t;
sum2 += t * t;
}
p1 += lsk;
}
/* Loop for output pels.
*/
for( x = 0; x < r->width; x++ ) {
/* Find stats.
*/
double mean = (double) sum / npel;
double var = (double) sum2 / npel - (mean * mean);
double sig = sqrt( var );
/* Transform.
*/
double res = f1 + f2 * mean +
((double) p[centre] - mean) *
(f3 / (inf->s0 + inf->b * sig));
/* And write.
*/
if( res < 0.0 )
q[x] = 0;
else if( res >= 256.0 )
q[x] = 255;
else
q[x] = res + 0.5;
/* Adapt sums - remove the pels from the left hand
* column, add in pels for a new right-hand column.
*/
p1 = p;
for( j = 0; j < inf->ywin; j++ ) {
int t1 = p1[0];
int t2 = p1[inf->xwin];
sum -= t1;
sum2 -= t1 * t1;
sum += t2;
sum2 += t2 * t2;
p1 += lsk;
}
p += 1;
}
}
return( 0 );
}
int
im_stdif_raw( IMAGE *in, IMAGE *out,
double a, double m0, double b, double s0,
int xwin, int ywin )
{
StdifInfo *inf;
if( xwin > in->Xsize ||
ywin > in->Ysize ) {
im_error( "im_stdif", "%s", _( "window too large" ) );
return( -1 );
}
if( xwin <= 0 ||
ywin <= 0 ) {
im_error( "im_lhisteq", "%s", _( "window too small" ) );
return( -1 );
}
if( m0 < 0 || m0 > 255 || a < 0 || a > 1.0 || b < 0 || b > 2 ||
s0 < 0 || s0 > 255 ) {
im_error( "im_stdif", "%s", _( "parameters out of range" ) );
return( -1 );
}
if( im_check_format( "im_stdif", in, IM_BANDFMT_UCHAR ) ||
im_check_uncoded( "im_stdif", in ) ||
im_check_mono( "im_stdif", in ) ||
im_piocheck( in, out ) )
return( -1 );
if( im_cp_desc( out, in ) )
return( -1 );
out->Xsize -= xwin;
out->Ysize -= ywin;
/* Save parameters.
*/
if( !(inf = IM_NEW( out, StdifInfo )) )
return( -1 );
inf->xwin = xwin;
inf->ywin = ywin;
inf->a = a;
inf->m0 = m0;
inf->b = b;
inf->s0 = s0;
/* Set demand hints. FATSTRIP is good for us, as THINSTRIP will cause
* too many recalculations on overlaps.
*/
if( im_demand_hint( out, IM_FATSTRIP, in, NULL ) )
return( -1 );
/* Write the hist.
*/
if( im_generate( out,
im_start_one, stdif_gen, im_stop_one, in, inf ) )
return( -1 );
return( 0 );
}
/**
* im_stdif:
* @in: input image
* @out: output image
* @a: weight of new mean
* @m0: target mean
* @b: weight of new deviation
* @s0:target deviation
* @xwin: width of region
* @ywin: height of region
*
* im_stdif() preforms statistical differencing according to the formula
* given in page 45 of the book "An Introduction to Digital Image
* Processing" by Wayne Niblack. This transformation emphasises the way in
* which a pel differs statistically from its neighbours. It is useful for
* enhancing low-contrast images with lots of detail, such as X-ray plates.
*
* At point (i,j) the output is given by the equation:
*
* vout(i,j) = @a * @m0 + (1 - @a) * meanv +
* (vin(i,j) - meanv) * (@b * @s0) / (@s0 + @b * stdv)
*
* Values @a, @m0, @b and @s0 are entered, while meanv and stdv are the values
* calculated over a moving window of size @xwin, @ywin centred on pixel (i,j).
* @m0 is the new mean, @a is the weight given to it. @s0 is the new standard
* deviation, @b is the weight given to it.
*
* Try:
*
* vips im_stdif $VIPSHOME/pics/huysum.v fred.v 0.5 128 0.5 50 11 11
*
* The operation works on one-band uchar images only, and writes a one-band
* uchar image as its result. The output image has the same size as the
* input.
*
* See also: im_lhisteq().
*
* Returns: 0 on success, -1 on error
*/
int
im_stdif( IMAGE *in, IMAGE *out,
double a, double m0, double b, double s0,
int xwin, int ywin )
{
IMAGE *t1;
if( !(t1 = im_open_local( out, "im_stdif:1", "p" )) ||
im_embed( in, t1, 1, xwin / 2, ywin / 2,
in->Xsize + xwin - 1,
in->Ysize + ywin - 1 ) ||
im_stdif_raw( t1, out, a, m0, b, s0, xwin, ywin ) )
return( -1 );
return( 0 );
}

412
libvips/histogram/stdif.c Normal file
View File

@ -0,0 +1,412 @@
/* statistical difference
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 02/05/1990
* Modified on :
* 6/8/93 JC
* - now works for odd window sizes
* - ANSIfication
* 25/5/95 JC
* - new IM_ARRAY() macro
* 25/1/96 JC
* - im_lhisteq() adapted to make new im_stdif()
* - now partial, plus rolling window
* - 5x faster, amazingly
* - works
* 7/4/04
* - now uses im_embed() with edge stretching on the input, not
* the output
* 25/3/10
* - gtkdoc
* - small cleanups
* 10/8/13
* - wrapped as a class using hist_local.c
* - many bands
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <vips/vips.h>
typedef struct _VipsStdif {
VipsOperation parent_instance;
VipsImage *in;
VipsImage *out;
int width;
int height;
double a;
double m0;
double b;
double s0;
} VipsStdif;
typedef VipsOperationClass VipsStdifClass;
G_DEFINE_TYPE( VipsStdif, vips_stdif, VIPS_TYPE_OPERATION );
/* How ugly and stupid.
*/
#define MAX_BANDS (100)
static int
vips_stdif_generate( VipsRegion *or,
void *vseq, void *a, void *b, gboolean *stop )
{
VipsRect *r = &or->valid;
VipsRegion *ir = (VipsRegion *) vseq;
VipsImage *in = (VipsImage *) a;
VipsStdif *stdif = (VipsStdif *) b;
int bands = in->Bands;
int npel = stdif->width * stdif->width;
VipsRect irect;
int y;
int lsk;
int centre; /* Offset to move to centre of window */
/* What part of ir do we need?
*/
irect.left = or->valid.left;
irect.top = or->valid.top;
irect.width = or->valid.width + stdif->width;
irect.height = or->valid.height + stdif->height;
if( vips_region_prepare( ir, &irect ) )
return( -1 );
lsk = VIPS_REGION_LSKIP( ir );
centre = lsk * (stdif->height / 2) + stdif->width / 2;
for( y = 0; y < r->height; y++ ) {
/* Get input and output pointers for this line.
*/
VipsPel *p = VIPS_REGION_ADDR( ir, r->left, r->top + y );
VipsPel *q = VIPS_REGION_ADDR( or, r->left, r->top + y );
double f1 = stdif->a * stdif->m0;
double f2 = 1.0 - stdif->a;
double f3 = stdif->b * stdif->s0;
VipsPel *p1;
int x, i, j, b;
/* We will get int overflow for windows larger than about 256
* x 256, sadly.
*/
unsigned int sum[MAX_BANDS];
unsigned int sum2[MAX_BANDS];
/* Find sum, sum of squares for the start of this line.
*/
for( b = 0; b < bands; b++ ) {
memset( sum, 0, bands * sizeof( unsigned int ) );
memset( sum2, 0, bands * sizeof( unsigned int ) );
}
p1 = p;
for( j = 0; j < stdif->height; j++ ) {
i = 0;
for( x = 0; x < stdif->width; x++ ) {
for( b = 0; b < bands; b++ ) {
int t = p1[i++];
sum[b] += t;
sum2[b] += t * t;
}
}
p1 += lsk;
}
/* Loop for output pels.
*/
for( x = 0; x < r->width; x++ ) {
for( b = 0; b < bands; b++ ) {
/* Find stats.
*/
double mean = (double) sum[b] / npel;
double var = (double) sum2[b] / npel -
(mean * mean);
double sig = sqrt( var );
/* Transform.
*/
double res = f1 + f2 * mean +
((double) p[centre] - mean) *
(f3 / (stdif->s0 + stdif->b * sig));
/* And write.
*/
if( res < 0.0 )
*q++ = 0;
else if( res >= 256.0 )
*q++ = 255;
else
*q++ = res + 0.5;
/* Adapt sums - remove the pels from the left
* hand column, add in pels for a new
* right-hand column.
*/
p1 = p;
for( j = 0; j < stdif->height; j++ ) {
int t1 = p1[0];
int t2 = p1[bands * stdif->width];
sum[b] -= t1;
sum2[b] -= t1 * t1;
sum[b] += t2;
sum2[b] += t2 * t2;
p1 += lsk;
}
p += 1;
}
}
}
return( 0 );
}
static int
vips_stdif_build( VipsObject *object )
{
VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
VipsStdif *stdif = (VipsStdif *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 3 );
VipsImage *in;
if( VIPS_OBJECT_CLASS( vips_stdif_parent_class )->build( object ) )
return( -1 );
in = stdif->in;
if( vips_check_uncoded( class->nickname, in ) ||
vips_check_format( class->nickname, in, VIPS_FORMAT_UCHAR ) )
return( -1 );
if( stdif->width > in->Xsize ||
stdif->height > in->Ysize ) {
vips_error( class->nickname, "%s", _( "window too large" ) );
return( -1 );
}
if( in->Bands > MAX_BANDS ) {
vips_error( class->nickname, "%s", _( "too many bands" ) );
return( -1 );
}
/* Expand the input.
*/
if( vips_embed( in, &t[0],
stdif->width / 2, stdif->height / 2,
in->Xsize + stdif->width - 1, in->Ysize + stdif->height - 1,
"extend", VIPS_EXTEND_COPY,
NULL ) )
return( -1 );
in = t[0];
g_object_set( object, "out", vips_image_new(), NULL );
if( vips_image_copy_fields( stdif->out, in ) )
return( -1 );
stdif->out->Xsize -= stdif->width - 1;
stdif->out->Ysize -= stdif->height - 1;
/* Set demand hints. FATSTRIP is good for us, as THINSTRIP will cause
* too many recalculations on overlaps.
*/
vips_demand_hint( stdif->out,
VIPS_DEMAND_STYLE_FATSTRIP, in, NULL );
if( vips_image_generate( stdif->out,
vips_start_one,
vips_stdif_generate,
vips_stop_one,
in, stdif ) )
return( -1 );
stdif->out->Xoffset = 0;
stdif->out->Yoffset = 0;
return( 0 );
}
static void
vips_stdif_class_init( VipsStdifClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *object_class = (VipsObjectClass *) class;
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
object_class->nickname = "stdif";
object_class->description = _( "statistical difference" );
object_class->build = vips_stdif_build;
VIPS_ARG_IMAGE( class, "in", 1,
_( "Input" ),
_( "Input image" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsStdif, in ) );
VIPS_ARG_IMAGE( class, "out", 2,
_( "Output" ),
_( "Output image" ),
VIPS_ARGUMENT_REQUIRED_OUTPUT,
G_STRUCT_OFFSET( VipsStdif, out ) );
/* Windows larger than 256x256 will overflow sum2, see above.
*/
VIPS_ARG_INT( class, "width", 4,
_( "Width" ),
_( "Window width in pixels" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsStdif, width ),
1, 256, 11 );
VIPS_ARG_INT( class, "height", 5,
_( "Height" ),
_( "Window height in pixels" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipsStdif, height ),
1, 256, 11 );
VIPS_ARG_DOUBLE( class, "a", 2,
_( "Mean weight" ),
_( "Weight of new mean" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsStdif, a ),
0.0, 1.0, 0.5 );
VIPS_ARG_DOUBLE( class, "m0", 2,
_( "Mean" ),
_( "New mean" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsStdif, m0 ),
-INFINITY, INFINITY, 128 );
VIPS_ARG_DOUBLE( class, "b", 2,
_( "Deviation weight" ),
_( "Weight of new deviation" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsStdif, b ),
0.0, 2.0, 0.5 );
VIPS_ARG_DOUBLE( class, "s0", 2,
_( "Deviation" ),
_( "New deviation" ),
VIPS_ARGUMENT_OPTIONAL_INPUT,
G_STRUCT_OFFSET( VipsStdif, s0 ),
-INFINITY, INFINITY, 50 );
}
static void
vips_stdif_init( VipsStdif *stdif )
{
stdif->width = 11;
stdif->height = 11;
stdif->a = 0.5;
stdif->m0 = 128.0;
stdif->b = 0.5;
stdif->s0 = 50.0;
}
/**
* vips_stdif:
* @in: input image
* @out: output image
* @width: width of region
* @height: height of region
*
* Optional arguments:
*
* @a: weight of new mean
* @m0: target mean
* @b: weight of new deviation
* @s0: target deviation
*
* vips_stdif() preforms statistical differencing according to the formula
* given in page 45 of the book "An Introduction to Digital Image
* Processing" by Wayne Niblack. This transformation emphasises the way in
* which a pel differs statistically from its neighbours. It is useful for
* enhancing low-contrast images with lots of detail, such as X-ray plates.
*
* At point (i,j) the output is given by the equation:
*
* vout(i,j) = @a * @m0 + (1 - @a) * meanv +
* (vin(i,j) - meanv) * (@b * @s0) / (@s0 + @b * stdv)
*
* Values @a, @m0, @b and @s0 are entered, while meanv and stdv are the values
* calculated over a moving window of size @width, @height centred on pixel
* (i,j). @m0 is the new mean, @a is the weight given to it. @s0 is the new
* standard deviation, @b is the weight given to it.
*
* Try:
*
* vips stdif $VIPSHOME/pics/huysum.v fred.v 0.5 128 0.5 50 11 11
*
* The operation works on one-band uchar images only, and writes a one-band
* uchar image as its result. The output image has the same size as the
* input.
*
* See also: vips_hist_local().
*
* Returns: 0 on success, -1 on error
*/
int
vips_stdif( VipsImage *in, VipsImage **out, int width, int height, ... )
{
va_list ap;
int result;
va_start( ap, height );
result = vips_call_split( "stdif", ap, in, out, width, height );
va_end( ap );
return( result );
}

6
libvips/include/vips/histogram.h
View File

@ -53,7 +53,8 @@ int vips_hist_match( VipsImage *in, VipsImage *ref, VipsImage **out, ... )
int vips_hist_local( VipsImage *in, VipsImage **out,
int width, int height, ... )
__attribute__((sentinel));
int vips_stdif( VipsImage *in, VipsImage **out, int width, int height, ... )
__attribute__((sentinel));
int im_project( VipsImage *in, VipsImage *hout, VipsImage *vout );
@ -62,9 +63,6 @@ int im_ismonotonic( VipsImage *lut, int *out );
int im_mpercent( VipsImage *in, double percent, int *out );
int im_mpercent_hist( VipsImage *hist, double percent, int *out );
int im_stdif( VipsImage *in, VipsImage *out,
double a, double m0, double b, double s0, int xwin, int ywin );
int im_tone_build_range( VipsImage *out,
int in_max, int out_max,
double Lb, double Lw, double Ps, double Pm, double Ph,

2
libvips/include/vips/vips7compat.h
View File

@ -864,6 +864,8 @@ int im_histplot( VipsImage *in, VipsImage *out );
int im_hsp( VipsImage *in, VipsImage *ref, VipsImage *out );
int im_histspec( VipsImage *in, VipsImage *ref, VipsImage *out );
int im_lhisteq( VipsImage *in, VipsImage *out, int xwin, int ywin );
int im_stdif( VipsImage *in, VipsImage *out,
double a, double m0, double b, double s0, int xwin, int ywin );
/* Not really correct, but who uses this.
*/