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jcupittjcupitt
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add vips_dither
compiles!
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‎libvips/conversion/conversion.c

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@@ -376,6 +376,7 @@ vips_conversion_operation_init( void )
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extern GType vips_composite_get_type( void );
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extern GType vips_copy_get_type( void );
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extern GType vips_crop_get_type( void );
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extern GType vips_dither_get_type( void );
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extern GType vips_embed_get_type( void );
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extern GType vips_extract_area_get_type( void );
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extern GType vips_extract_band_get_type( void );
@@ -426,6 +427,7 @@ vips_conversion_operation_init( void )
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vips_composite_get_type();
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vips_copy_get_type();
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vips_crop_get_type();
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vips_dither_get_type();
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vips_embed_get_type();
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vips_extract_area_get_type();
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vips_extract_band_get_type();

‎libvips/conversion/dither.c

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@@ -0,0 +1,281 @@
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/* find a dither
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*
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* 25/9/22
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* - from cgifsave.c
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*/
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/*
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This file is part of VIPS.
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VIPS is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA
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*/
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/*
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These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /*HAVE_CONFIG_H*/
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#include <glib/gi18n-lib.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <vips/vips.h>
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#include <vips/internal.h>
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#include "pconversion.h"
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#include "../foreign/quantise.h"
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typedef struct _VipsDither {
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VipsConversion parent_instance;
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VipsImage *in;
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VipsImage *palette;
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double dither;
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VipsQuantiseAttr *attr;
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VipsQuantiseImage *image;
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VipsQuantiseResult *result;
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} VipsDither;
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typedef VipsConversionClass VipsDitherClass;
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G_DEFINE_TYPE( VipsDither, vips_dither, VIPS_TYPE_CONVERSION );
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static void
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vips_dither_dispose( GObject *gobject )
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{
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VipsDither *dither = (VipsDither *) gobject;
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VIPS_FREEF( vips__quantise_result_destroy, dither->result );
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VIPS_FREEF( vips__quantise_image_destroy, dither->image );
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VIPS_FREEF( vips__quantise_attr_destroy, dither->attr );
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G_OBJECT_CLASS( vips_dither_parent_class )->dispose( gobject );
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}
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static int
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vips_dither_to_rgba( VipsDither *dither, VipsImage *in, VipsImage **out )
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{
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VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( dither );
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VipsImage **t = (VipsImage **)
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vips_object_local_array( VIPS_OBJECT( dither ), 1 );
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VipsImage *rgba;
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rgba = in;
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g_object_ref( rgba );
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if( vips_check_uncoded( class->nickname, rgba ) ||
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vips_check_format( class->nickname, rgba, VIPS_FORMAT_UCHAR ) ||
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vips_check_bands_atleast( class->nickname, rgba, 3 ) ) {
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VIPS_UNREF( rgba );
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return( -1 );
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}
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if( rgba->Bands == 3 ) {
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if( vips_addalpha( rgba, &t[0], NULL ) ) {
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VIPS_UNREF( rgba );
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return( -1 );
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}
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rgba = t[0];
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}
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else if( rgba->Bands > 4 ) {
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if( vips_extract_band( rgba, &t[0], 0, "n", 4, NULL ) ) {
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VIPS_UNREF( rgba );
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return( -1 );
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}
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rgba = t[0];
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}
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*out = rgba;
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return( 0 );
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}
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static int
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vips_dither_build( VipsObject *object )
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{
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VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
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VipsConversion *conversion = VIPS_CONVERSION( object );
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VipsDither *dither = (VipsDither *) object;
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VipsImage **t = (VipsImage **) vips_object_local_array( object, 5 );
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VipsImage *in;
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VipsImage *palette;
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guint32 fake_image[257];
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int n_colours;
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if( VIPS_OBJECT_CLASS( vips_dither_parent_class )->build( object ) )
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return( -1 );
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in = dither->in;
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palette = dither->palette;
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/* The palette can't have more than 256 entries.
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*/
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if( palette->Xsize != 1 &&
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palette->Ysize != 1 ) {
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vips_error( class->nickname, "%s",
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_( "palettes must have width or height 1" ) );
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return( -1 );
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}
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if( VIPS_IMAGE_N_PELS( palette ) > 256 ) {
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vips_error( class->nickname, "%s",
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_( "palettes must have not have more than "
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"256 elements" ) );
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return( -1 );
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}
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n_colours = palette->Xsize * palette->Ysize;
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/* We only work for 8-bit RGBA images.
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*/
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if( vips_dither_to_rgba( dither, in, &t[0] ) ||
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vips_dither_to_rgba( dither, palette, &t[1] ) )
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return( -1 );
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in = t[0];
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palette = t[1];
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/* We need the whole thing in memory.
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*/
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if( vips_image_wio_input( in ) ||
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vips_image_wio_input( palette ) )
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return( -1 );
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dither->attr = vips__quantise_attr_create();
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vips__quantise_set_max_colors( dither->attr, n_colours );
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vips__quantise_set_quality( dither->attr, 0, 100 );
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/* Make a fake image from the input palette and quantise that to get
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* the context we use for dithering.
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*/
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memcpy( fake_image, VIPS_IMAGE_ADDR( palette, 0, 0 ),
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n_colours * sizeof( int ) );
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dither->image = vips__quantise_image_create_rgba( dither->attr,
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fake_image, n_colours, 1, 0.0 );
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if( vips__quantise_image_quantize_fixed( dither->image,
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dither->attr, &dither->result ) ) {
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vips_error( class->nickname,
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"%s", _( "quantisation failed" ) );
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return( -1 );
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}
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VIPS_FREEF( vips__quantise_image_destroy, dither->image );
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/* The frame index buffer.
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*/
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vips_image_init_fields( conversion->out,
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in->Xsize, in->Ysize, 1,
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VIPS_FORMAT_UCHAR,
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VIPS_CODING_NONE, VIPS_INTERPRETATION_B_W, 1.0, 1.0 );
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if( vips_image_write_prepare( conversion->out ) )
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return( -1 );
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dither->image = vips__quantise_image_create_rgba( dither->attr,
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VIPS_IMAGE_ADDR( conversion->out, 0, 0 ),
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conversion->out->Xsize, conversion->out->Ysize, 0.0 );
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/* Now dither!
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*/
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vips__quantise_set_dithering_level( dither->result, dither->dither );
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if( vips__quantise_write_remapped_image( dither->result, dither->image,
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VIPS_IMAGE_ADDR( conversion->out, 0, 0 ),
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VIPS_IMAGE_N_PELS( conversion->out ) ) ) {
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vips_error( class->nickname, "%s", _( "dither failed" ) );
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return( -1 );
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}
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return( 0 );
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}
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static void
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vips_dither_class_init( VipsDitherClass *class )
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{
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GObjectClass *gobject_class = G_OBJECT_CLASS( class );
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VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
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VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
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gobject_class->dispose = vips_dither_dispose;
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gobject_class->set_property = vips_object_set_property;
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gobject_class->get_property = vips_object_get_property;
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vobject_class->nickname = "dither";
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vobject_class->description = _( "dither image into palette" );
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vobject_class->build = vips_dither_build;
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operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
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VIPS_ARG_IMAGE( class, "in", 0,
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_( "Input" ),
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_( "Input image" ),
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VIPS_ARGUMENT_REQUIRED_INPUT,
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G_STRUCT_OFFSET( VipsDither, in ) );
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VIPS_ARG_IMAGE( class, "palette", 0,
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_( "Palette" ),
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_( "Palette image" ),
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VIPS_ARGUMENT_REQUIRED_INPUT,
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G_STRUCT_OFFSET( VipsDither, palette ) );
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VIPS_ARG_DOUBLE( class, "dither", 10,
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_( "Dithering" ),
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_( "Amount of dithering" ),
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VIPS_ARGUMENT_OPTIONAL_INPUT,
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G_STRUCT_OFFSET( VipsDither, dither ),
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0.0, 1.0, 1.0 );
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}
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static void
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vips_dither_init( VipsDither *dither )
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{
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}
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/**
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* vips_dither: (method)
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* @in: input image
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* @out: (out): output image
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* @palette: (in): palette image
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* @...: %NULL-terminated list of optional named arguments
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*
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* Optional arguments:
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*
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* * @dither: %gdouble, dithering level
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*
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* Dither @in using @palette.
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*
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* Use @dither to set the degree of Floyd-Steinberg dithering.
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*
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* See also: vips_palette().
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*
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* Returns: 0 on success, -1 on error
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*/
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int
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vips_dither( VipsImage *in, VipsImage **out, VipsImage *palette, ... )
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{
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va_list ap;
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int result;
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va_start( ap, palette );
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result = vips_call_split( "dither", ap, in, out, palette );
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va_end( ap );
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return( result );
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}

‎libvips/conversion/meson.build

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Original file line numberDiff line numberDiff line change
@@ -14,6 +14,7 @@ conversion_sources = files(
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'composite.cpp',
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'conversion.c',
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'copy.c',
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'dither.c',
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'embed.c',
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'extract.c',
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'falsecolour.c',

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