start vips_case()

libvips/histogram/Makefile.am

@@ -5,6 +5,7 @@ libhistogram_la_SOURCES = \
 	phistogram.h \
 	maplut.c \
 	switch.c \
+	case.c \
 	hist_unary.c \
 	hist_unary.h \
 	hist_cum.c \

libvips/histogram/case.c

@@ -0,0 +1,308 @@
+/* use pixel values to case between an array of images
+ *
+ * 28/7/19
+ * 	- from maplut.c
+ */
+
+/*
+
+    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 <vips/vips.h>
+#include <vips/internal.h>
+
+typedef struct _VipsCase {
+	VipsOperation parent_instance;
+
+	VipsImage *in;
+	VipsImage *out;
+	VipsArrayImage *lut;
+	int n;
+
+} VipsCase;
+
+typedef VipsOperationClass VipsCaseClass;
+
+G_DEFINE_TYPE( VipsCase, vips_case, VIPS_TYPE_OPERATION );
+
+/* Do a map.
+ */
+static int 
+vips_case_gen( VipsRegion *or, void *seq, void *a, void *b, 
+	gboolean *stop )
+{
+	VipsRegion **ar = (VipsRegion **) seq;
+	VipsCase *swit = (VipsCase *) b;
+	VipsRect *r = &or->valid;
+	VipsRegion *index = ar[swit->n];
+
+	int x, y, i, j;
+	VipsPel * restrict ip;
+	VipsPel * restrict q;
+	size_t ils;
+	size_t qls;
+	int hist[256];
+	VipsPel * restrict p[256];
+	size_t ls[256];
+	size_t ps;
+
+	if( vips_region_prepare( index, r ) )
+		return( -1 );
+
+	g_assert( index->im->BandFmt == VIPS_FORMAT_UCHAR );
+	g_assert( index->im->Bands == 1 );
+
+	/* Histogram of input region, so we know which of our inputs we will
+	 * need to prepare.
+	 */
+	memset( hist, 0, 256 * sizeof( int ) );
+	ip = VIPS_REGION_ADDR( index, r->left, r->top );
+	ils = VIPS_REGION_LSKIP( index );
+	for( y = 0; y < r->height; y++ ) {
+		for( x = 0; x < r->width; x++ )
+			hist[ip[x]] += 1;
+
+		ip += ils;
+	}
+
+	for( i = 0; i < 256; i++ ) 
+		if( hist[i] ) {
+			if( vips_region_prepare( ar[i], r ) )
+				return( -1 );
+			p[i] = VIPS_REGION_ADDR( ar[i], r->left, r->top );
+			ls[i] = VIPS_REGION_LSKIP( ar[i] );
+		}
+
+	ip = VIPS_REGION_ADDR( index, r->left, r->top );
+	q = VIPS_REGION_ADDR( or, r->left, r->top );
+	qls = VIPS_REGION_LSKIP( or );
+	ps = VIPS_IMAGE_SIZEOF_PEL( or->im );
+	for( y = 0; y < r->height; y++ ) {
+		i = 0;
+		for( x = 0; x < r->width; x++ ) {
+			VipsPel * restrict pv = p[ip[x]];
+
+			for( j = 0; j < ps; j++ ) {
+				q[i] = pv[i];
+				i += 1;
+			}
+		}
+
+		ip += ils;
+		q += qls;
+		for( i = 0; i < 256; i++ ) 
+			if( hist[i] ) 
+				p[i] += ls[i];
+	}
+
+	return( 0 );
+}
+
+static int
+vips_case_build( VipsObject *object )
+{
+	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
+	VipsCase *swit = (VipsCase *) object;
+	VipsImage **t = (VipsImage **) vips_object_local_array( object, 2 );
+
+	VipsImage *in;
+	VipsImage **lut;
+	VipsImage **decode;
+	VipsImage **format;
+	VipsImage **band;
+	VipsImage **size;
+	int i;
+
+	g_object_set( object, "out", vips_image_new(), NULL ); 
+
+	if( VIPS_OBJECT_CLASS( vips_case_parent_class )->build( object ) )
+		return( -1 );
+
+	in = swit->in;
+	lut = vips_area_get_data( &swit->lut->area, 
+		NULL, &swit->n, NULL, NULL );
+	if( swit->n > 256 ) {
+		vips_error( class->nickname, "%s", _( "LUT too large" ) );
+		return( -1 );
+	}
+	if( in->Bands > 1 ) {
+		vips_error( class->nickname, 
+			"%s", _( "index image not 1-band" ) );
+		return( -1 );
+	}
+
+	/* Cast @in to u8 to make the index image.
+	 */
+	if( vips_cast( in, &t[0], VIPS_FORMAT_UCHAR, NULL ) )
+		return( -1 );
+	in = t[0];
+
+	decode = (VipsImage **) vips_object_local_array( object, swit->n );
+	format = (VipsImage **) vips_object_local_array( object, swit->n );
+	band = (VipsImage **) vips_object_local_array( object, swit->n + 1 );
+	size = (VipsImage **) vips_object_local_array( object, swit->n + 1 );
+
+	/* Decode RAD/LABQ etc.
+	 */
+	for( i = 0; i < swit->n; i++ )
+		if( vips_image_decode( lut[i], &decode[i] ) )
+			return( -1 );
+	lut = decode;
+
+	/* LUT images must match in format, size and bands.
+	 *
+	 * We want everything sized up to the size of the index image, so add
+	 * that to the end of the set of images for sizealike.
+	 */
+	band[swit->n] = in;
+	g_object_ref( in ); 
+	if( vips__formatalike_vec( lut, format, swit->n ) ||
+		vips__bandalike_vec( class->nickname, 
+			format, band, swit->n, 1 ) ||
+		vips__sizealike_vec( band, size, swit->n + 1 ) ) 
+		return( -1 );
+	lut = size;
+
+	swit->out->BandFmt = lut[0]->BandFmt;
+	swit->out->Bands = lut[0]->Bands;
+	swit->out->Type = lut[0]->Type;
+	swit->out->Xsize = in->Xsize;
+	swit->out->Ysize = in->Ysize;
+
+	if( vips_image_pipeline_array( swit->out, 
+		VIPS_DEMAND_STYLE_THINSTRIP, lut ) )
+		return( -1 );
+
+	if( vips_image_generate( swit->out,
+		vips_start_many, vips_case_gen, vips_stop_many, 
+		lut, swit ) )
+		return( -1 );
+
+	return( 0 );
+}
+
+static void
+vips_case_class_init( VipsCaseClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *object_class = VIPS_OBJECT_CLASS( class );
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	object_class->nickname = "case";
+	object_class->description = 
+		_( "use pixel values to case between a set of images" );
+	object_class->build = vips_case_build;
+
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
+
+	VIPS_ARG_IMAGE( class, "in", 1, 
+		_( "Input" ), 
+		_( "Input image" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsCase, in ) );
+
+	VIPS_ARG_IMAGE( class, "out", 2, 
+		_( "Output" ), 
+		_( "Output image" ),
+		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
+		G_STRUCT_OFFSET( VipsCase, out ) );
+
+	VIPS_ARG_BOXED( class, "lut", 3, 
+		_( "LUT" ), 
+		_( "Look-up table of images" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsCase, lut ),
+		VIPS_TYPE_ARRAY_IMAGE );
+
+}
+
+static void
+vips_case_init( VipsCase *swit )
+{
+}
+
+static int
+vips_casev( VipsImage *in, VipsImage **out, VipsImage **lut, int n, 
+	va_list ap )
+{
+	VipsArrayImage *array; 
+	int result;
+
+	array = vips_array_image_new( lut, n ); 
+	result = vips_call_split( "case", ap, in, out, array );
+	vips_area_unref( VIPS_AREA( array ) );
+
+	return( result );
+}
+
+/**
+ * vips_case: (method)
+ * @in: input image
+ * @out: (out): output image
+ * @lut: (array length=n): LUT of input images
+ * @n: number of input images
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Use pixel values to case between an array of images.
+ *
+ * Each value in @in is used to select an image from @lut, and the
+ * corresponding pixel is copied to the output.
+ *
+ * @in must have one band. @lut can have up to 256 elements. Values in @in
+ * greater than or equal to @n use the final image in @lut. The images in @lut
+ * must have either one band or the same number of bands. The output image is
+ * the same size as @in. Images in @lut are expanded to the smallest common
+ * format and number of bands.
+ *
+ * See also: vips_maplut().
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_case( VipsImage *in, VipsImage **out, VipsImage **lut, int n, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, n );
+	result = vips_casev( in, out, lut, n, ap );
+	va_end( ap );
+
+	return( result );
+}
+

libvips/include/vips/histogram.h

@@ -64,6 +64,11 @@ int vips_hist_ismonotonic( VipsImage *in, gboolean *out, ... )
 int vips_hist_entropy( VipsImage *in, double *out, ... )
 	__attribute__((sentinel));
 
+int vips_switch( VipsImage *in, VipsImage **out, VipsImage **lut, int n, ... )
+	__attribute__((sentinel));
+int vips_case( VipsImage *in, VipsImage **out, VipsImage **lut, int n, ... )
+	__attribute__((sentinel));
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/