353 lines
8.2 KiB
C
353 lines
8.2 KiB
C
/* Build a LUT from a set of x/y points.
|
|
*
|
|
* Written on: 26/9/06
|
|
* - from im_invertlut()
|
|
* 9/10/06
|
|
* - don't output x values
|
|
* 18/3/09
|
|
* - saner limit and rounding behaviour
|
|
* 30/3/09
|
|
* - argh, fixed again
|
|
* 22/6/09
|
|
* - more fixes for tables that don't start at zero (thanks Jack)
|
|
* 23/3/10
|
|
* - gtkdoc
|
|
* 2/7/13
|
|
* - convert to a class
|
|
* 10/12/13
|
|
* - be more forgiving about x vales not quite integers
|
|
*/
|
|
|
|
/*
|
|
|
|
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
|
|
|
|
*/
|
|
|
|
/*
|
|
#define DEBUG
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include <config.h>
|
|
#endif /*HAVE_CONFIG_H*/
|
|
#include <glib/gi18n-lib.h>
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
|
|
#include <vips/vips.h>
|
|
|
|
#include "pcreate.h"
|
|
|
|
typedef struct _VipsBuildlut {
|
|
VipsCreate parent_instance;
|
|
|
|
/* Input image.
|
|
*/
|
|
VipsImage *in;
|
|
|
|
/* .. and cast to a matrix.
|
|
*/
|
|
VipsImage *mat;
|
|
|
|
int xlow; /* Index 0 in output is this x */
|
|
int lut_size; /* Number of output elements to generate */
|
|
double **data; /* Matrix row pointers */
|
|
double *buf; /* Output buffer */
|
|
} VipsBuildlut;
|
|
|
|
typedef VipsCreateClass VipsBuildlutClass;
|
|
|
|
G_DEFINE_TYPE( VipsBuildlut, vips_buildlut, VIPS_TYPE_CREATE );
|
|
|
|
static void
|
|
vips_buildlut_dispose( GObject *gobject )
|
|
{
|
|
VipsBuildlut *lut = (VipsBuildlut *) gobject;
|
|
|
|
VIPS_FREE( lut->data );
|
|
VIPS_FREE( lut->buf );
|
|
VIPS_UNREF( lut->mat );
|
|
|
|
G_OBJECT_CLASS( vips_buildlut_parent_class )->dispose( gobject );
|
|
}
|
|
|
|
/* Use this to sort our input rows by the first column.
|
|
*/
|
|
static int
|
|
vips_buildlut_compare( const void *a, const void *b )
|
|
{
|
|
double **r1 = (double **) a;
|
|
double **r2 = (double **) b;
|
|
|
|
double diff = r1[0][0] - r2[0][0];
|
|
|
|
if( diff > 0 )
|
|
return( 1 );
|
|
else if( diff == 0 )
|
|
return( 0 );
|
|
else
|
|
return( -1 );
|
|
}
|
|
|
|
static int
|
|
vips_buildlut_build_init( VipsBuildlut *lut )
|
|
{
|
|
VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( lut );
|
|
|
|
int y;
|
|
int xlow, xhigh;
|
|
|
|
/* Need xlow and xhigh to get the size of the LUT we build.
|
|
*/
|
|
xlow = xhigh = *VIPS_MATRIX( lut->mat, 0, 0 );
|
|
for( y = 0; y < lut->mat->Ysize; y++ ) {
|
|
double v = *VIPS_MATRIX( lut->mat, 0, y );
|
|
|
|
/* Allow for being a bit off.
|
|
*/
|
|
if( VIPS_FABS( v - VIPS_RINT( v ) ) > 0.001 ) {
|
|
vips_error( class->nickname,
|
|
_( "x value row %d not an int" ), y );
|
|
return( -1 );
|
|
}
|
|
|
|
v = VIPS_RINT( v );
|
|
|
|
if( v < xlow )
|
|
xlow = v;
|
|
if( v > xhigh )
|
|
xhigh = v;
|
|
}
|
|
lut->xlow = xlow;
|
|
lut->lut_size = xhigh - xlow + 1;
|
|
|
|
if( lut->lut_size < 1 ) {
|
|
vips_error( class->nickname, "%s", _( "x range too small" ) );
|
|
return( -1 );
|
|
}
|
|
|
|
if( !(lut->data = VIPS_ARRAY( NULL, lut->mat->Ysize, double * )) )
|
|
return( -1 );
|
|
for( y = 0; y < lut->mat->Ysize; y++ )
|
|
lut->data[y] = VIPS_MATRIX( lut->mat, 0, y );
|
|
|
|
if( !(lut->buf = VIPS_ARRAY( NULL,
|
|
lut->lut_size * (lut->mat->Xsize - 1), double )) )
|
|
return( -1 );
|
|
|
|
/* Sort by 1st column in input.
|
|
*/
|
|
qsort( lut->data, lut->mat->Ysize,
|
|
sizeof( double * ), vips_buildlut_compare );
|
|
|
|
#ifdef DEBUG
|
|
printf( "Input table, sorted by 1st column\n" );
|
|
for( y = 0; y < lut->mat->Ysize; y++ ) {
|
|
int x;
|
|
|
|
printf( "%.4d ", y );
|
|
|
|
for( x = 0; x < lut->mat->Xsize; x++ )
|
|
printf( "%.9f ", lut->data[y][x] );
|
|
|
|
printf( "\n" );
|
|
}
|
|
#endif /*DEBUG*/
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int
|
|
vips_buildlut_build_create( VipsBuildlut *lut )
|
|
{
|
|
const int xlow = lut->xlow;
|
|
const VipsImage *mat = lut->mat;
|
|
const int xsize = mat->Xsize;
|
|
const int ysize = mat->Ysize;
|
|
const int bands = xsize - 1;
|
|
const int xlast = lut->data[ysize - 1][0];
|
|
|
|
int b, i, x;
|
|
|
|
/* Do each output channel separately.
|
|
*/
|
|
for( b = 0; b < bands; b++ ) {
|
|
for( i = 0; i < ysize - 1; i++ ) {
|
|
const int x1 = VIPS_RINT( lut->data[i][0] );
|
|
const int x2 = VIPS_RINT( lut->data[i + 1][0] );
|
|
const int dx = x2 - x1;
|
|
const double y1 = lut->data[i][b + 1];
|
|
const double y2 = lut->data[i + 1][b + 1];
|
|
const double dy = y2 - y1;
|
|
|
|
for( x = 0; x < dx; x++ )
|
|
lut->buf[b + (x + x1 - xlow) * bands] =
|
|
y1 + x * dy / dx;
|
|
}
|
|
|
|
/* We are inclusive: pop the final value in by hand.
|
|
*/
|
|
lut->buf[b + (xlast - xlow) * bands] =
|
|
lut->data[ysize - 1][b + 1];
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int
|
|
vips_buildlut_build( VipsObject *object )
|
|
{
|
|
VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
|
|
VipsCreate *create = VIPS_CREATE( object );
|
|
VipsBuildlut *lut = (VipsBuildlut *) object;
|
|
|
|
if( VIPS_OBJECT_CLASS( vips_buildlut_parent_class )->build( object ) )
|
|
return( -1 );
|
|
|
|
if( vips_check_matrix( class->nickname, lut->in, &lut->mat ) )
|
|
return( -1 );
|
|
|
|
if( vips_buildlut_build_init( lut ) ||
|
|
vips_buildlut_build_create( lut ) )
|
|
return( -1 );
|
|
|
|
vips_image_init_fields( create->out,
|
|
lut->lut_size, 1, lut->mat->Xsize - 1,
|
|
VIPS_FORMAT_DOUBLE, VIPS_CODING_NONE,
|
|
VIPS_INTERPRETATION_HISTOGRAM, 1.0, 1.0 );
|
|
if( vips_image_write_line( create->out, 0, (VipsPel *) lut->buf ) )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static void
|
|
vips_buildlut_class_init( VipsBuildlutClass *class )
|
|
{
|
|
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
|
|
VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
|
|
|
|
gobject_class->dispose = vips_buildlut_dispose;
|
|
gobject_class->set_property = vips_object_set_property;
|
|
gobject_class->get_property = vips_object_get_property;
|
|
|
|
vobject_class->nickname = "buildlut";
|
|
vobject_class->description = _( "build a look-up table" );
|
|
vobject_class->build = vips_buildlut_build;
|
|
|
|
VIPS_ARG_IMAGE( class, "in", 0,
|
|
_( "Input" ),
|
|
_( "Matrix of XY coordinates" ),
|
|
VIPS_ARGUMENT_REQUIRED_INPUT,
|
|
G_STRUCT_OFFSET( VipsBuildlut, in ) );
|
|
|
|
}
|
|
|
|
static void
|
|
vips_buildlut_init( VipsBuildlut *lut )
|
|
{
|
|
}
|
|
|
|
/**
|
|
* vips_buildlut: (method)
|
|
* @in: input matrix
|
|
* @out: (out): output image
|
|
* @...: %NULL-terminated list of optional named arguments
|
|
*
|
|
* This operation builds a lookup table from a set of points. Intermediate
|
|
* values are generated by piecewise linear interpolation. The lookup table is
|
|
* always of type #VIPS_FORMAT_DOUBLE, use vips_cast() to change it to the
|
|
* type you need.
|
|
*
|
|
* For example, consider this 2 x 2 matrix of (x, y) coordinates:
|
|
*
|
|
* <tgroup cols='2' align='left' colsep='1' rowsep='1'>
|
|
* <tbody>
|
|
* <row>
|
|
* <entry>0</entry>
|
|
* <entry>0</entry>
|
|
* </row>
|
|
* <row>
|
|
* <entry>255</entry>
|
|
* <entry>100</entry>
|
|
* </row>
|
|
* </tbody>
|
|
* </tgroup>
|
|
*
|
|
* We then generate:
|
|
*
|
|
* <tgroup cols='2' align='left' colsep='1' rowsep='1'>
|
|
* <thead>
|
|
* <row>
|
|
* <entry>Index</entry>
|
|
* <entry>Value</entry>
|
|
* </row>
|
|
* </thead>
|
|
* <tbody>
|
|
* <row>
|
|
* <entry>0</entry>
|
|
* <entry>0</entry>
|
|
* </row>
|
|
* <row>
|
|
* <entry>1</entry>
|
|
* <entry>0.4</entry>
|
|
* </row>
|
|
* <row>
|
|
* <entry>...</entry>
|
|
* <entry>etc. by linear interpolation</entry>
|
|
* </row>
|
|
* <row>
|
|
* <entry>255</entry>
|
|
* <entry>100</entry>
|
|
* </row>
|
|
* </tbody>
|
|
* </tgroup>
|
|
*
|
|
* This is then written as the output image, with the left column giving the
|
|
* index in the image to place the value.
|
|
*
|
|
* The (x, y) points don't need to be sorted: we do that. You can have
|
|
* several Ys, each becomes a band in the output LUT. You don't need to
|
|
* start at zero, any integer will do, including negatives.
|
|
*
|
|
* See also: vips_identity(), vips_invertlut(), vips_cast(), vips_maplut().
|
|
*
|
|
* Returns: 0 on success, -1 on error
|
|
*/
|
|
int
|
|
vips_buildlut( VipsImage *in, VipsImage **out, ... )
|
|
{
|
|
va_list ap;
|
|
int result;
|
|
|
|
va_start( ap, out );
|
|
result = vips_call_split( "buildlut", ap, in, out );
|
|
va_end( ap );
|
|
|
|
return( result );
|
|
}
|