add vips_resize()

a wrapper over affine that just scales ... much faster from the
command-line, since it can set SEQ mode

ChangeLog

@@ -1,5 +1,6 @@
 25/7/14 started 7.41.0
 - start working on --disable-deprecated
+- add vips_resize()
 
 12/8/14 started 7.40.5
 - more doc fixes

libvips/create/gaussmat.c

@@ -157,8 +157,8 @@ vips_gaussmat_class_init( VipsGaussmatClass *class )
 	vobject_class->build = vips_gaussmat_build;
 
 	VIPS_ARG_DOUBLE( class, "sigma", 2, 
-		_( "Radius" ), 
-		_( "Radius of Gaussian" ),
+		_( "Sigma" ), 
+		_( "Sigma of Gaussian" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsGaussmat, sigma ),
 		0.000001, 10000.0, 1.0 );

libvips/include/vips/resample.h

@@ -43,6 +43,9 @@ int vips_shrink( VipsImage *in, VipsImage **out,
 	__attribute__((sentinel));
 int vips_similarity( VipsImage *in, VipsImage **out, ... )
 	__attribute__((sentinel));
+int vips_resize( VipsImage *in, VipsImage **out, 
+	double h_scale, double v_scale, ... )
+	__attribute__((sentinel));
 int vips_affine( VipsImage *in, VipsImage **out, 
 	double a, double b, double c, double d, ... )
 	__attribute__((sentinel));

libvips/resample/Makefile.am

@@ -9,6 +9,7 @@ libresample_la_SOURCES = \
 	quadratic.c \
 	resample.c \
 	similarity.c \
+	resize.c \
 	presample.h \
 	shrink.c \
 	interpolate.c \

libvips/resample/affine.c

@@ -1,4 +1,4 @@
-/* im_affine() ... affine transform with a supplied interpolator.
+/* affine transform with a supplied interpolator.
  *
  * 
  * Copyright N. Dessipris

libvips/resample/resample.c

@@ -115,10 +115,12 @@ vips_resample_operation_init( void )
 	extern GType vips_quadratic_get_type( void ); 
 	extern GType vips_affine_get_type( void ); 
 	extern GType vips_similarity_get_type( void ); 
+	extern GType vips_resize_get_type( void ); 
 
 	vips_shrink_get_type(); 
 	vips_quadratic_get_type(); 
 	vips_affine_get_type(); 
 	vips_similarity_get_type(); 
+	vips_resize_get_type(); 
 }
 

libvips/resample/resize.c

@@ -0,0 +1,196 @@
+/* resize an image ... a simple wrapper over affine
+ *
+ * 13/8/14
+ * 	- from affine.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
+
+ */
+
+/*
+#define DEBUG_VERBOSE
+#define DEBUG
+ */
+
+#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 <limits.h>
+
+#include <vips/vips.h>
+#include <vips/debug.h>
+#include <vips/internal.h>
+#include <vips/transform.h>
+
+#include "presample.h"
+
+typedef struct _VipsResize {
+	VipsResample parent_instance;
+
+	double h_scale;
+	double v_scale;
+	VipsInterpolate *interpolate;
+	double idx;
+	double idy;
+
+} VipsResize;
+
+typedef VipsResampleClass VipsResizeClass;
+
+G_DEFINE_TYPE( VipsResize, vips_resize, VIPS_TYPE_RESAMPLE ); 
+
+static int
+vips_resize_build( VipsObject *object )
+{
+	VipsResample *resample = VIPS_RESAMPLE( object );
+	VipsResize *resize = (VipsResize *) object;
+
+	VipsImage **t = (VipsImage **) 
+		vips_object_local_array( object, 4 );
+
+	double a, b, c, d; 
+
+	if( VIPS_OBJECT_CLASS( vips_resize_parent_class )->build( object ) )
+		return( -1 );
+
+	a = resize->h_scale;
+	b = 0.0;
+	c = 0.0;
+	d = resize->v_scale;
+
+	if( vips_affine( resample->in, &t[0], a, b, c, d, 
+		"interpolate", resize->interpolate,
+		"idx", resize->idx,
+		"idy", resize->idy,
+		NULL ) ||
+		vips_image_write( t[0], resample->out ) )
+		return( -1 ); 
+
+	return( 0 );
+}
+
+static void
+vips_resize_class_init( VipsResizeClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
+
+	VIPS_DEBUG_MSG( "vips_resize_class_init\n" );
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	vobject_class->nickname = "resize";
+	vobject_class->description = _( "resize an image" );
+	vobject_class->build = vips_resize_build;
+
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
+
+	VIPS_ARG_DOUBLE( class, "h_scale", 113, 
+		_( "Horizontal scale factor" ), 
+		_( "Scale image by this factor in the horizontal axis" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsResize, h_scale ),
+		0, 10000000, 0 );
+
+	VIPS_ARG_DOUBLE( class, "v_scale", 114, 
+		_( "Vertical scale factor" ), 
+		_( "Scale image by this factor in the vertical axis" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsResize, v_scale ),
+		0, 10000000, 0 );
+
+	VIPS_ARG_INTERPOLATE( class, "interpolate", 2, 
+		_( "Interpolate" ), 
+		_( "Interpolate pixels with this" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT, 
+		G_STRUCT_OFFSET( VipsResize, interpolate ) );
+
+	VIPS_ARG_DOUBLE( class, "idx", 115, 
+		_( "Input offset" ), 
+		_( "Horizontal input displacement" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsResize, idx ),
+		-10000000, 10000000, 0 );
+
+	VIPS_ARG_DOUBLE( class, "idy", 116, 
+		_( "Input offset" ), 
+		_( "Vertical input displacement" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsResize, idy ),
+		-10000000, 10000000, 0 );
+}
+
+static void
+vips_resize_init( VipsResize *resize )
+{
+}
+
+/**
+ * vips_resize:
+ * @in: input image
+ * @out: output image
+ * @h_scale: horizontal scale factor
+ * @v_scale: vertical scale factor
+ *
+ * Optional arguments:
+ *
+ * @interpolate: interpolate pixels with this
+ * @idx: input horizontal offset
+ * @idy: input vertical offset
+ *
+ * @interpolate defaults to bilinear. 
+ *
+ * @idx, @idy default to zero.
+ *
+ * See also: vips_shrink(), vips_affine(), #VipsInterpolate.
+ *
+ * Returns: 0 on success, -1 on error
+ */
+int
+vips_resize( VipsImage *in, VipsImage **out, 
+	double h_scale, double v_scale, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, v_scale );
+	result = vips_call_split( "affine", ap, in, out, h_scale, v_scale );
+	va_end( ap );
+
+	return( result );
+}
+
+
+

libvips/resample/similarity.c

@@ -1,8 +1,8 @@
-/* simple wrapper over vips_similarity() to make scale / rotate easy from the
+/* simple wrapper over vips_affine() to make scale / rotate easy from the
  * command-line
  *
  * 3/10/13
- * 	- from similarity.c
+ * 	- from affine.c
  * 25/10/13
  * 	- oops, reverse rotation direction to match the convention used in the
  * 	  rest of vips