diff --git a/TODO b/TODO
index 707fb5f9..6d18b34c 100644
--- a/TODO
+++ b/TODO
@@ -1,25 +1,24 @@
-- need vips load/save class, so we can detect vips files for native read /
-  write
+- do jpegbuffer load and save
 
-  jpeg load needs to set suffs
+  need a jpegsave base class, with subclasses for save to file and save to 
+  buffer
 
-  get image.c using the new system for vips_image_new_from_file()
-
-  CLI stuff image->new_from_string() needs to use new system too, chcek this
-
-  savers need it too ... delayed save system and also
-  image->output_to_arg()
+  same for jpegload
 
   make compat wrappers for old im_jpeg2vips() and im_vips2jpeg()
 
-  move format/* to deprecated
+  make sure we are using the operation cache for jpegload
+
+  have something to print the cache before we flush it?
 
   try tiff load
 
+  move format/* to deprecated
+
+
 
 
 
-- return missing just after read_xmp() in master?
 
 
 
diff --git a/libvips/deprecated/dispatch_types.c b/libvips/deprecated/dispatch_types.c
index 1178d9d3..53f7a23f 100644
--- a/libvips/deprecated/dispatch_types.c
+++ b/libvips/deprecated/dispatch_types.c
@@ -876,6 +876,10 @@ input_interpolate_init( im_object *obj, char *str )
 	interpolate_class = vips_class_find( "VipsInterpolate", "interpolate" );
 	if( !(object = vips_object_new_from_string( interpolate_class, str )) )
 		return( -1 );
+	if( vips_object_build( object ) ) {
+		g_object_unref( object );
+		return( -1 );
+	}
 	*obj = object;
 
 	return( 0 );
diff --git a/libvips/file/file.c b/libvips/file/file.c
index f6816e4e..ada5fb45 100644
--- a/libvips/file/file.c
+++ b/libvips/file/file.c
@@ -234,7 +234,7 @@ vips_file_print_class( VipsObjectClass *object_class, VipsBuf *buf )
 
 	VIPS_OBJECT_CLASS( vips_file_parent_class )->
 		print_class( object_class, buf );
-	vips_buf_appends( buf, ", " );
+	vips_buf_appends( buf, " " );
 
 	if( class->suffs ) {
 		vips_buf_appends( buf, "(" );
@@ -243,7 +243,7 @@ vips_file_print_class( VipsObjectClass *object_class, VipsBuf *buf )
 			if( p[1] )
 				vips_buf_appends( buf, ", " );
 		}
-		vips_buf_appends( buf, ") " );
+		vips_buf_appends( buf, "), " );
 	}
 
 	vips_buf_appendf( buf, "priority=%d", class->priority );
@@ -364,6 +364,77 @@ vips_file_load_print_class( VipsObjectClass *object_class, VipsBuf *buf )
 		vips_buf_appends( buf, ", load" );
 }
 
+/* Can this VipsFile open this file?
+ */
+static void *
+vips_file_load_new_from_file_sub( VipsFileLoadClass *load_class, 
+	const char *filename )
+{
+	VipsFileClass *class = VIPS_FILE_CLASS( load_class );
+
+	if( load_class->is_a ) {
+		if( load_class->is_a( filename ) ) 
+			return( load_class );
+	}
+	else if( vips_filename_suffix_match( filename, class->suffs ) )
+		return( load_class );
+
+	return( NULL );
+}
+
+/**
+ * vips_file_find_load:
+ * @filename: file to find a file for
+ *
+ * Searches for an operation you could use to load a file. 
+ *
+ * See also: vips_file_read().
+ *
+ * Returns: the nmae of an operation on success, %NULL on error
+ */
+const char *
+vips_file_find_load( const char *filename )
+{
+	VipsFileLoadClass *load_class;
+
+	if( !vips_existsf( "%s", filename ) ) {
+		vips_error( "VipsFileLoad", 
+			_( "file \"%s\" not found" ), filename );
+		return( NULL );
+	}
+
+	if( !(load_class = (VipsFileLoadClass *) vips_file_map( 
+		"VipsFileLoad",
+		(VipsSListMap2Fn) vips_file_load_new_from_file_sub, 
+		(void *) filename, NULL )) ) {
+		vips_error( "VipsFileLoad", 
+			_( "file \"%s\" not a known file" ), filename );
+		return( NULL );
+	}
+
+	return( G_OBJECT_CLASS_NAME( load_class ) );
+}
+
+static VipsObject *
+vips_file_load_new_from_string( const char *string )
+{
+	const char *file_op;
+	GType type;
+	VipsFileLoad *load;
+
+	if( !(file_op = vips_file_find_load( string )) )
+		return( NULL );
+	type = g_type_from_name( file_op );
+	g_assert( type ); 
+
+	load = VIPS_FILE_LOAD( g_object_new( type, NULL ) );
+	g_object_set( load,
+		"filename", string,
+		NULL );
+
+	return( VIPS_OBJECT( load ) );
+}
+
 static size_t
 vips_get_disc_threshold( void )
 {
@@ -414,7 +485,7 @@ vips_file_load_start_cb( VipsImage *out, void *a, void *dummy )
 		 */
 		if( load->disc && 
 			disc_threshold && 
-			(load->flags & VIPS_FORMAT_PARTIAL) &&
+			(load->flags & VIPS_FILE_PARTIAL) &&
 			image_size > disc_threshold ) 
 			if( !(load->real = vips_image_new_disc_temp( "%s.v" )) )
 				return( NULL );
@@ -476,24 +547,34 @@ vips_file_load_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	/* Read header fields to init the return image. THINSTRIP since this is
-	 * probably a disc file. We can't tell yet whether we will be opening
-	 * to memory, sadly, so we can't suggest ANY.
+	/* Read the header into @out.
 	 */
 	if( class->header &&
 		class->header( load ) )
 		return( -1 );
-	vips_demand_hint( load->out, VIPS_DEMAND_STYLE_THINSTRIP, NULL );
 
-	/* Then 'start' creates the real image and 'gen' fetches pixels for 
-	 * 'out' from real on demand.
+	/* If there's no ->load() method then the header read has done
+	 * everything. Otherwise, it's just set fields and we now must
+	 * convert pixels on demand.
 	 */
-	if( vips_image_generate( load->out, 
-		vips_file_load_start_cb, 
-		vips_file_load_generate_cb, 
-		vips_stop_one, 
-		load, NULL ) )
-		return( -1 );
+	if( class->load ) {
+		/* THINSTRIP since this is probably a disc file. 
+		 * We can't tell yet whether we will be opening
+		 * to memory, sadly, so we can't suggest ANY.
+		 */
+		vips_demand_hint( load->out, 
+			VIPS_DEMAND_STYLE_THINSTRIP, NULL );
+
+		/* Then 'start' creates the real image and 'gen' fetches 
+		 * pixels for @out from @real on demand.
+		 */
+		if( vips_image_generate( load->out, 
+			vips_file_load_start_cb, 
+			vips_file_load_generate_cb, 
+			vips_stop_one, 
+			load, NULL ) )
+			return( -1 );
+	}
 
 	return( 0 );
 }
@@ -508,10 +589,11 @@ vips_file_load_class_init( VipsFileLoadClass *class )
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
+	object_class->build = vips_file_load_build;
+	object_class->print_class = vips_file_load_print_class;
+	object_class->new_from_string = vips_file_load_new_from_string;
 	object_class->nickname = "fileload";
 	object_class->description = _( "file loaders" );
-	object_class->print_class = vips_file_load_print_class;
-	object_class->build = vips_file_load_build;
 
 	VIPS_ARG_IMAGE( class, "out", 2, 
 		_( "Output" ), 
@@ -541,57 +623,6 @@ vips_file_load_init( VipsFileLoad *load )
 	load->disc = TRUE;
 }
 
-/* Can this file open this file?
- */
-static void *
-vips_file_load_new_from_file_sub( VipsFileLoadClass *load_class, 
-	const char *filename )
-{
-	VipsFileClass *class = VIPS_FILE_CLASS( load_class );
-
-	if( load_class->is_a ) {
-		if( load_class->is_a( filename ) ) 
-			return( load_class );
-	}
-	else if( vips_filename_suffix_match( filename, class->suffs ) )
-		return( load_class );
-
-	return( NULL );
-}
-
-/**
- * vips_file_find_load:
- * @filename: file to find a file for
- *
- * Searches for an operation you could use to load a file. 
- *
- * See also: vips_file_read().
- *
- * Returns: the nmae of an operation on success, %NULL on error
- */
-const char *
-vips_file_find_load( const char *filename )
-{
-	VipsFileLoadClass *load_class;
-
-	if( !vips_existsf( "%s", filename ) ) {
-		vips_error( "VipsFileLoad", 
-			_( "file \"%s\" not found" ), filename );
-		return( NULL );
-	}
-
-	if( !(load_class = (VipsFileLoadClass *) vips_file_map( 
-		"VipsFileLoad",
-		(VipsSListMap2Fn) vips_file_load_new_from_file_sub, 
-		(void *) filename, NULL )) ) {
-		vips_error( "VipsFileLoad", 
-			_( "file \"%s\" not a known file" ), filename );
-		return( NULL );
-	}
-
-	return( G_OBJECT_CLASS_NAME( load_class ) );
-}
-
 /* Abstract base class for image savers.
  */
 
@@ -619,6 +650,69 @@ vips_file_save_print_class( VipsObjectClass *object_class, VipsBuf *buf )
 		VIPS_ENUM_NICK( VIPS_TYPE_SAVEABLE, class->saveable ) );
 }
 
+/* Can we write this filename with this file? 
+ */
+static void *
+vips_file_save_new_from_filename_sub( VipsFileSaveClass *save_class, 
+	const char *filename )
+{
+	VipsFileClass *class = VIPS_FILE_CLASS( save_class );
+
+	if( vips_filename_suffix_match( filename, class->suffs ) )
+		return( save_class );
+
+	return( NULL );
+}
+
+/**
+ * vips_file_find_save:
+ * @filename: name to find a file for
+ *
+ * Searches for an operation you could use to save a file.
+ *
+ * See also: vips_file_write().
+ *
+ * Returns: the name of an operation on success, %NULL on error
+ */
+const char *
+vips_file_find_save( const char *filename )
+{
+	VipsFileSaveClass *save_class;
+
+	if( !(save_class = (VipsFileSaveClass *) vips_file_map( 
+		"VipsFileSave",
+		(VipsSListMap2Fn) vips_file_save_new_from_filename_sub, 
+		(void *) filename, NULL )) ) {
+		vips_error( "VipsFileSave",
+			_( "\"%s\" is not a supported image file." ), 
+			filename );
+
+		return( NULL );
+	}
+
+	return( G_OBJECT_CLASS_NAME( save_class ) );
+}
+
+static VipsObject *
+vips_file_save_new_from_string( const char *string )
+{
+	const char *file_op;
+	GType type;
+	VipsFileSave *save;
+
+	if( !(file_op = vips_file_find_save( string )) )
+		return( NULL );
+	type = g_type_from_name( file_op );
+	g_assert( type ); 
+
+	save = VIPS_FILE_SAVE( g_object_new( type, NULL ) );
+	g_object_set( save,
+		"filename", string,
+		NULL );
+
+	return( VIPS_OBJECT( save ) );
+}
+
 /* Generate the saveable image.
  */
 static int
@@ -843,10 +937,11 @@ vips_file_save_class_init( VipsFileSaveClass *class )
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
+	object_class->build = vips_file_save_build;
+	object_class->print_class = vips_file_save_print_class;
+	object_class->new_from_string = vips_file_save_new_from_string;
 	object_class->nickname = "filesave";
 	object_class->description = _( "file savers" );
-	object_class->print_class = vips_file_save_print_class;
-	object_class->build = vips_file_save_build;
 
 	VIPS_ARG_IMAGE( class, "in", 0, 
 		_( "Input" ), 
@@ -860,49 +955,6 @@ vips_file_save_init( VipsFileSave *object )
 {
 }
 
-/* Can we write this filename with this file? 
- */
-static void *
-vips_file_save_new_from_filename_sub( VipsFileSaveClass *save_class, 
-	const char *filename )
-{
-	VipsFileClass *class = VIPS_FILE_CLASS( save_class );
-
-	if( vips_filename_suffix_match( filename, class->suffs ) )
-		return( save_class );
-
-	return( NULL );
-}
-
-/**
- * vips_file_find_save:
- * @filename: name to find a file for
- *
- * Searches for an operation you could use to save a file.
- *
- * See also: vips_file_write().
- *
- * Returns: the name of an operation on success, %NULL on error
- */
-const char *
-vips_file_find_save( const char *filename )
-{
-	VipsFileSaveClass *save_class;
-
-	if( !(save_class = (VipsFileSaveClass *) vips_file_map( 
-		"VipsFileSave",
-		(VipsSListMap2Fn) vips_file_save_new_from_filename_sub, 
-		(void *) filename, NULL )) ) {
-		vips_error( "VipsFileSave",
-			_( "\"%s\" is not a supported image file." ), 
-			filename );
-
-		return( NULL );
-	}
-
-	return( G_OBJECT_CLASS_NAME( save_class ) );
-}
-
 /**
  * vips_file_read:
  * @filename: file to load
diff --git a/libvips/file/jpegload.c b/libvips/file/jpegload.c
index a74d6d8d..d1d386a3 100644
--- a/libvips/file/jpegload.c
+++ b/libvips/file/jpegload.c
@@ -901,11 +901,14 @@ vips_file_load_jpeg_load( VipsFileLoad *load )
 	return( result );
 }
 
+static const char *jpeg_suffs[] = { ".jpg", ".jpeg", ".jpe", NULL };
+
 static void
 vips_file_load_jpeg_class_init( VipsFileLoadJpegClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsFileClass *file_class = (VipsFileClass *) class;
 	VipsFileLoadClass *load_class = (VipsFileLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -915,6 +918,8 @@ vips_file_load_jpeg_class_init( VipsFileLoadJpegClass *class )
 	object_class->description = _( "load jpeg from file" );
 	object_class->build = vips_file_load_jpeg_build;
 
+	file_class->suffs = jpeg_suffs;
+
 	load_class->is_a = vips_file_load_jpeg_is_a;
 	load_class->header = vips_file_load_jpeg_header;
 	load_class->load = vips_file_load_jpeg_load;
@@ -932,7 +937,6 @@ vips_file_load_jpeg_class_init( VipsFileLoadJpegClass *class )
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsFileLoadJpeg, fail ),
 		FALSE );
-
 }
 
 static void
diff --git a/libvips/file/jpegsave.c b/libvips/file/jpegsave.c
index 639bf888..642b7b37 100644
--- a/libvips/file/jpegsave.c
+++ b/libvips/file/jpegsave.c
@@ -852,7 +852,6 @@ vips_file_save_jpeg_class_init( VipsFileSaveJpegClass *class )
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsFileSaveJpeg, profile ),
 		NULL );
-
 }
 
 static void
diff --git a/libvips/file/vipsload.c b/libvips/file/vipsload.c
index 60ff1a77..fbff46a1 100644
--- a/libvips/file/vipsload.c
+++ b/libvips/file/vipsload.c
@@ -42,38 +42,31 @@
 #include <stdlib.h>
 
 #include <vips/vips.h>
+#include <vips/internal.h>
 
 typedef VipsFileLoad VipsFileLoadVips;
 typedef VipsFileLoadClass VipsFileLoadVipsClass;
 
-G_DEFINE_TYPE( VipsFileLoadVips, vips_file_load_vips, VIPS_TYPE_FILE_SAVE );
+G_DEFINE_TYPE( VipsFileLoadVips, vips_file_load_vips, VIPS_TYPE_FILE_LOAD );
 
-static int
-vips_file_load_vips_build( VipsObject *object )
+static gboolean
+vips_file_load_vips_is_a( const char *filename )
 {
-	if( VIPS_OBJECT_CLASS( vips_file_load_vips_parent_class )->
-		build( object ) )
-		return( -1 );
-
-	return( 0 );
+	return( vips__file_magic( filename ) );
 }
 
 static int
-vips_file_load_vips_is_a( const char *filename )
+vips_file_load_vips_get_flags( VipsFileLoad *load )
 {
-	unsigned char buf[4];
+	VipsFile *file = VIPS_FILE( load );
 
-	if( vips__get_bytes( filename, buf, 4 ) ) {
-		if( buf[0] == 0x08 && buf[1] == 0xf2 &&
-			buf[2] == 0xa6 && buf[3] == 0xb6 )
-			/* SPARC-order VIPS image.
-			 */
-			return( 1 );
-		else if( buf[3] == 0x08 && buf[2] == 0xf2 &&
-			buf[1] == 0xa6 && buf[0] == 0xb6 )
-			/* INTEL-order VIPS image.
-			 */
-			return( 1 );
+	load->flags = VIPS_FILE_PARTIAL;
+
+	if( vips__file_magic( file->filename ) == VIPS_MAGIC_INTEL ) {
+		printf( "vips_file_load_vips_get_flags: "
+			"%s is intel, setting bigendian\n",
+			file->filename );
+		load->flags |= VIPS_FILE_BIGENDIAN;
 	}
 
 	return( 0 );
@@ -82,33 +75,45 @@ vips_file_load_vips_is_a( const char *filename )
 static int
 vips_file_load_vips_header( VipsFileLoad *load )
 {
-}
+	VipsFile *file = VIPS_FILE( load );
+	VipsImage *out;
+	VipsImage *out2;
 
-static int
-vips_file_load_vips_load( VipsFileLoad *load )
-{
+	if( !(out2 = vips_image_new_from_file( file->filename )) )
+		return( -1 );
+
+	/* Remove the @out that's there now.
+	 */
+	g_object_get( load, "out", &out, NULL ); 
+	g_object_set( load, "out", out2, NULL ); 
+
+	/* Unref after we install the new out to make sure load isn't
+	 * disposed.
+	 */
+	g_object_unref( out );
+	g_object_unref( out );
+
+	return( 0 );
 }
 
 static const char *vips_suffs[] = { ".v", NULL };
 
 static void
-vips_file_load_jpeg_class_init( VipsFileLoadJpegClass *class )
+vips_file_load_vips_class_init( VipsFileLoadVipsClass *class )
 {
-	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
-	VipsFileClass *file_class = (VipsLoadClass *) class;
+	VipsFileClass *file_class = (VipsFileClass *) class;
 	VipsFileLoadClass *load_class = (VipsFileLoadClass *) class;
 
 	object_class->nickname = "vipsload";
 	object_class->description = _( "load vips from file" );
-	object_class->build = vips_file_load_vips_build;
 
 	file_class->suffs = vips_suffs;
 
 	load_class->is_a = vips_file_load_vips_is_a;
+	load_class->get_flags = vips_file_load_vips_get_flags;
 	load_class->header = vips_file_load_vips_header;
-	load_class->load = vips_file_load_vips_load;
-
+	load_class->load = NULL;
 }
 
 static void
diff --git a/libvips/file/vipssave.c b/libvips/file/vipssave.c
index 1f87efa0..57080ea1 100644
--- a/libvips/file/vipssave.c
+++ b/libvips/file/vipssave.c
@@ -61,7 +61,7 @@ vips_file_save_vips_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	if( vips_image_write_to_file( save->in, file->filename ) )
+	if( vips_image_write_to_file( save->ready, file->filename ) )
 		return( -1 );
 
 	return( 0 );
@@ -105,7 +105,6 @@ vips_file_save_vips_class_init( VipsFileSaveVipsClass *class )
 
 	save_class->saveable = VIPS_SAVEABLE_ANY;
 	save_class->format_table = vips_bandfmt_vips;
-
 }
 
 static void
diff --git a/libvips/include/vips/file.h b/libvips/include/vips/file.h
index bd8f596a..3f6e962b 100644
--- a/libvips/include/vips/file.h
+++ b/libvips/include/vips/file.h
@@ -104,7 +104,7 @@ void *vips_file_map( const char *base, VipsSListMap2Fn fn, void *a, void *b );
 /* Image file properties. 
  */
 typedef enum {
-	VIPS_FILE_NONE = 0,		/* No flags set */
+	VIPS_FILE_NONE = 0,	/* No flags set */
 	VIPS_FILE_PARTIAL = 1,	/* Lazy read OK (eg. tiled tiff) */
 	VIPS_FILE_BIGENDIAN = 2	/* Most-significant byte first */
 } VipsFileFlags;
@@ -145,11 +145,13 @@ typedef struct _VipsFileLoadClass {
 	 */
 	int (*get_flags)( VipsFileLoad * );
 
-	/* Read the header into @out.
+	/* Set the header fields in @out from @filename. If you can read the 
+	 * whole image as well with no performance cost (as with vipsload),
+	 * leave ->load() NULL.
 	 */
 	int (*header)( VipsFileLoad * );
 
-	/* Read the whole image into real. It gets copied to out later.
+	/* Read the whole image into @real. It gets copied to @out later.
 	 */
 	int (*load)( VipsFileLoad * );
 
diff --git a/libvips/include/vips/internal.h b/libvips/include/vips/internal.h
index 7cc16db7..b69a4505 100644
--- a/libvips/include/vips/internal.h
+++ b/libvips/include/vips/internal.h
@@ -107,6 +107,7 @@ void vips__read_4byte( int msb_first, unsigned char *to, unsigned char **from );
 void vips__read_2byte( int msb_first, unsigned char *to, unsigned char **from );
 void vips__write_4byte( unsigned char **to, unsigned char *from );
 void vips__write_2byte( unsigned char **to, unsigned char *from );
+guint32 vips__file_magic( const char *filename );
 int vips__has_extension_block( VipsImage *im );
 void *vips__read_extension_block( VipsImage *im, int *size );
 int vips__write_extension_block( VipsImage *im, void *buf, int size );
diff --git a/libvips/iofuncs/generate.c b/libvips/iofuncs/generate.c
index 08568665..a5ee7210 100644
--- a/libvips/iofuncs/generate.c
+++ b/libvips/iofuncs/generate.c
@@ -682,7 +682,7 @@ vips_image_generate( VipsImage *image,
                  */
 		vips_error( "VipsImage", 
 			_( "unable to output to a %s image" ),
-			VIPS_ENUM_NICK( VIPS_TYPE_DEMAND_STYLE, 
+			VIPS_ENUM_NICK( VIPS_TYPE_IMAGE_TYPE, 
 				image->dtype ) );
                 return( -1 );
         }
diff --git a/libvips/iofuncs/image.c b/libvips/iofuncs/image.c
index 97bbc77b..d24d979d 100644
--- a/libvips/iofuncs/image.c
+++ b/libvips/iofuncs/image.c
@@ -460,220 +460,30 @@ vips_image_rewind( VipsObject *object )
 	image->mode = mode;
 }
 
-static gboolean
-vips_format_is_vips( VipsFormatClass *format )
-{
-	return( strcmp( VIPS_OBJECT_CLASS( format )->nickname, "vips" ) == 0 );
-}
-
-/* Lazy open.
- */
-
-/* What we track during a delayed open.
- */
-typedef struct {
-	VipsImage *image;
-	VipsFormatClass *format;/* Read in pixels with this */
-	char *filename;		/* Get pixels from here */
-	gboolean disc;		/* Read via disc requested */
-
-	VipsImage *real;	/* The real decompressed image */
-} Lazy;
-
-static void
-lazy_free_cb( VipsImage *image, Lazy *lazy )
-{
-	VIPS_DEBUG_MSG( "lazy_free: %p \"%s\"\n", lazy, lazy->filename );
-
-	g_free( lazy->filename );
-	VIPS_UNREF( lazy->real );
-	g_free( lazy );
-}
-
-static Lazy *
-lazy_new( VipsImage *image, 
-	VipsFormatClass *format, const char *filename, gboolean disc )
-{
-	Lazy *lazy;
-
-	lazy = g_new( Lazy, 1 );
-	VIPS_DEBUG_MSG( "lazy_new: %p \"%s\"\n", lazy, filename );
-	lazy->image = image;
-	lazy->format = format;
-	lazy->filename = g_strdup( filename );
-	lazy->disc = disc;
-	lazy->real = NULL;
-	g_signal_connect( image, "close", G_CALLBACK( lazy_free_cb ), lazy );
-
-	return( lazy );
-}
-
-static size_t
-disc_threshold( void )
-{
-	static gboolean done = FALSE;
-	static size_t threshold;
-
-	if( !done ) {
-		const char *env;
-
-		done = TRUE;
-
-		/* 100mb default.
-		 */
-		threshold = 100 * 1024 * 1024;
-
-		if( (env = g_getenv( "IM_DISC_THRESHOLD" )) ) 
-			threshold = vips__parse_size( env );
-
-		if( vips__disc_threshold ) 
-			threshold = vips__parse_size( vips__disc_threshold );
-
-		VIPS_DEBUG_MSG( "disc_threshold: %zd bytes\n", threshold );
-	}
-
-	return( threshold );
-}
-
-/* Make the real underlying image: either a direct disc file, or a temp file
- * somewhere.
- */
-static VipsImage *
-lazy_real_image( Lazy *lazy ) 
-{
-	VipsImage *real;
-
-	/* We open via disc if:
-	 * - 'disc' is set
-	 * - disc_threshold() has not been set to zero
-	 * - the format does not support lazy read
-	 * - the uncompressed image will be larger than disc_threshold()
-	 */
-	real = NULL;
-	if( lazy->disc && 
-		disc_threshold() && 
-	        !(vips_format_get_flags( lazy->format, lazy->filename ) & 
-			VIPS_FORMAT_PARTIAL) &&
-		VIPS_IMAGE_SIZEOF_IMAGE( lazy->image ) > disc_threshold() ) 
-			if( !(real = vips_image_new_disc_temp( "%s.v" )) )
-				return( NULL );
-
-	/* Otherwise, fall back to a "p".
-	 */
-	if( !real && 
-		!(real = vips_image_new()) )
-		return( NULL );
-
-	return( real );
-}
-
-/* Our start function ... do the lazy open, if necessary, and return a region
- * on the new image.
- */
-static void *
-open_lazy_start( VipsImage *out, void *a, void *dummy )
-{
-	Lazy *lazy = (Lazy *) a;
-
-	if( !lazy->real ) {
-		if( !(lazy->real = lazy_real_image( lazy )) || 
-			lazy->format->load( lazy->filename, lazy->real ) ||
-			vips_image_pio_input( lazy->real ) ) {
-			VIPS_UNREF( lazy->real );
-			return( NULL );
-		}
-	}
-
-	return( vips_region_new( lazy->real ) );
-}
-
-/* Just copy.
- */
-static int
-open_lazy_generate( VipsRegion *or, 
-	void *seq, void *a, void *b, gboolean *stop )
-{
-	VipsRegion *ir = (VipsRegion *) seq;
-
-        VipsRect *r = &or->valid;
-
-        /* Ask for input we need.
-         */
-        if( vips_region_prepare( ir, r ) )
-                return( -1 );
-
-        /* Attach output region to that.
-         */
-        if( vips_region_region( or, ir, r, r->left, r->top ) )
-                return( -1 );
-
-        return( 0 );
-}
-
-/* Lazy open ... init the header with the first OpenLazyFn, delay actually
- * decoding pixels with the second OpenLazyFn until the first generate().
- */
-static int
-vips_image_open_lazy( VipsImage *image, 
-	VipsFormatClass *format, const char *filename, gboolean disc )
-{
-	Lazy *lazy;
-
-	lazy = lazy_new( image, format, filename, disc );
-
-	/* Read header fields to init the return image. THINSTRIP since this is
-	 * probably a disc file. We can't tell yet whether we will be opening
-	 * to memory, sadly, so we can't suggest ANY.
-	 */
-	if( format->header( filename, image ) )
-		return( -1 );
-	vips_demand_hint( image, VIPS_DEMAND_STYLE_THINSTRIP, NULL );
-
-	/* Then 'start' creates the real image and 'gen' paints 'out' with 
-	 * pixels from the real image on demand.
-	 */
-	if( vips_image_generate( image, 
-		open_lazy_start, open_lazy_generate, vips_stop_one, 
-		lazy, NULL ) )
-		return( -1 );
-
-	return( 0 );
-}
-
-/* Lazy save.
+/* Delayed save.
  */
 
 /* If we write to (eg.) TIFF, actually do the write
- * to a "p" and on "written" do im_vips2tiff() or whatever. Track save
- * parameters here.
+ * to a "p" and on "written" do im_vips2tiff() or whatever. 
  */
-typedef struct {
-	int (*save_fn)();	/* Save function */
-	char *filename;		/* Save args */
-} SaveBlock;
 
 /* From "written" callback: invoke a delayed save.
  */
 static void
-vips_image_save_cb( VipsImage *image, int *result, SaveBlock *sb )
+vips_image_save_cb( VipsImage *image, int *result, char *filename )
 {
-	if( sb->save_fn( image, sb->filename ) )
+	if( vips_file_write( image, filename, NULL ) )
 		*result = -1;
 
-	g_free( sb->filename );
-	g_free( sb );
+	g_free( filename );
 }
 
 static void
-vips_attach_save( VipsImage *image, int (*save_fn)(), const char *filename )
+vips_attach_save( VipsImage *image, const char *filename )
 {
-	SaveBlock *sb;
-
-	sb = g_new( SaveBlock, 1 );
-	sb->save_fn = save_fn;
-	sb->filename = g_strdup( filename );
 	g_signal_connect( image, "written", 
-		G_CALLBACK( vips_image_save_cb ), sb );
+		G_CALLBACK( vips_image_save_cb ), 
+		g_strdup( filename ) );
 }
 
 /* Progress feedback. 
@@ -756,7 +566,7 @@ vips_image_build( VipsObject *object )
 	const char *filename = image->filename;
 	const char *mode = image->mode;
 
-	const char *file_op;
+	guint32 magic;
 	size_t sizeof_image;
 
 	VIPS_DEBUG_MSG( "vips_image_build: %p\n", image );
@@ -767,62 +577,84 @@ vips_image_build( VipsObject *object )
 	/* Parse the mode string.
 	 */
 	switch( mode[0] ) {
-        case 'r':
-		if( !(file_op = vips_file_find_load( filename )) )
+        case 'v':
+		/* Used by 'r' for native open of vips, see below.
+		 */
+		if( vips_image_open_input( image ) )
 			return( -1 );
 
-		if( vips_format_is_vips( format ) ) {
+		break;
+
+        case 'r':
+		if( (magic = vips__file_magic( filename )) ) {
 			/* We may need to byteswap.
 			 */
-			VipsFormatFlags flags = 
-				vips_format_get_flags( format, filename );
-			gboolean native = (flags & VIPS_FORMAT_BIGENDIAN) == 
-				vips_amiMSBfirst();
+			guint32 us = vips_amiMSBfirst() ? 
+				VIPS_MAGIC_INTEL : VIPS_MAGIC_SPARC;
 
-			if( native ) {
+			if( magic == us ) {
+				/* Native open.
+				 */
 				if( vips_image_open_input( image ) )
 					return( -1 );
-
-				if( mode[1] == 'w' ) 
-					image->dtype = VIPS_IMAGE_MMAPINRW;
 			}
 			else {
-				VipsImage *x;
+				VipsImage *t; 
+				VipsImage *t2;
 
-				if( !(x = vips_image_new()) )
+				/* Open the image in t, then byteswap to this
+				 * image.
+				 */
+				if( !(t = vips_image_new_mode( filename, 
+					"v" )) )
 					return( -1 );
-				vips_object_local( image, x );
-				if( vips_image_open_input( x ) )
+
+				if( vips_copy( t, &t2, 
+					"swap", TRUE,
+					NULL ) ) {
+					g_object_unref( t );
 					return( -1 );
+				}
+				g_object_unref( t );
+
 				image->dtype = VIPS_IMAGE_PARTIAL;
-				if( im_copy_swap( x, image ) )
+				if( vips_image_write( t2, image ) ) {
+					g_object_unref( t2 );
 					return( -1 );
+				}
+				g_object_unref( t2 );
 			}
 		}
 		else {
-			/* Make this a partial, generate into it from the
-			 * converter.
-			 */
-			image->dtype = VIPS_IMAGE_PARTIAL;
+			VipsImage *t;
 
-			if( vips_image_open_lazy( image, format, 
-				filename, mode[1] == 'd' ) )
+			if( vips_file_read( filename, &t, NULL ) )
 				return( -1 );
+
+			image->dtype = VIPS_IMAGE_PARTIAL;
+			if( vips_image_write( t, image ) ) {
+				g_object_unref( t );
+				return( -1 );
+			}
+			g_object_unref( t );
 		}
 
         	break;
 
 	case 'w':
-		if( !(format = vips_format_for_name( filename )) ) 
+{
+		const char *file_op;
+
+		if( !(file_op = vips_file_find_save( filename )) )
 			return( -1 );
 
-		if( vips_format_is_vips( format ) ) 
+		if( strcmp( file_op, "VipsFileSaveVips" ) == 0 ) 
 			image->dtype = VIPS_IMAGE_OPENOUT;
 		else {
 			image->dtype = VIPS_IMAGE_PARTIAL;
-			vips_attach_save( image, 
-				format->save, filename );
+			vips_attach_save( image, filename );
 		}
+}
         	break;
 
         case 't':
@@ -1964,7 +1796,7 @@ vips_image_write_line( VipsImage *image, int ypos, PEL *linebuffer )
 	default:
 		vips_error( "VipsImage", 
 			_( "unable to output to a %s image" ),
-			VIPS_ENUM_STRING( VIPS_TYPE_DEMAND_STYLE, 
+			VIPS_ENUM_STRING( VIPS_TYPE_IMAGE_TYPE, 
 				image->dtype ) );
 		return( -1 );
 	}
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index 90bce3ad..fcfe2a91 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -1231,19 +1231,61 @@ vips_object_set_argument_from_string( VipsObject *object,
 
 	g_assert( argument_class->flags & VIPS_ARGUMENT_INPUT );
 
-	if( g_type_is_a( otype, VIPS_TYPE_OBJECT ) &&
-		(oclass = g_type_class_ref( otype )) ) { 
-		VipsObject *object;
+	if( g_type_is_a( otype, VIPS_TYPE_IMAGE ) &&
+		(oclass = g_type_class_ref( VIPS_TYPE_FILE_LOAD )) ) { 
+		VipsObject *new_object;
+		VipsImage *out;
 
-		if( !(object = vips_object_new_from_string( oclass, value )) )
+		/* Use VipsFile to build images, then pull @out from it and
+		 * use that to set the value.
+		 */
+		if( !(new_object = 
+			vips_object_new_from_string( oclass, value )) )
 			return( -1 );
 
+		if( vips_object_build( new_object ) ) {
+			g_object_unref( new_object );
+			return( -1 );
+		}
+
+		g_object_get( new_object, "out", &out, NULL );
+
+		/* Getting @out will have upped it's count and we want to
+		 * hold the only ref to it.
+		 */
+		g_object_unref( out );
+
+		/* @out holds a ref to new_object, we can drop ours.
+		 */
+		g_object_unref( new_object );
+
+		g_value_init( &gvalue, VIPS_TYPE_IMAGE );
+		g_value_set_object( &gvalue, out );
+
+		/* Setting gvalue will have upped @out's count again,
+		 * go back to 1 so that gvalue has the only ref.
+		 */
+		g_object_unref( out );
+	}
+	else if( g_type_is_a( otype, VIPS_TYPE_OBJECT ) &&
+		(oclass = g_type_class_ref( otype )) ) { 
+		VipsObject *new_object;
+
+		if( !(new_object = 
+			vips_object_new_from_string( oclass, value )) )
+			return( -1 );
+
+		if( vips_object_build( new_object ) ) {
+			g_object_unref( new_object );
+			return( -1 );
+		}
+
 		g_value_init( &gvalue, G_TYPE_OBJECT );
-		g_value_set_object( &gvalue, object );
+		g_value_set_object( &gvalue, new_object );
 
 		/* The GValue now has a ref, we can drop ours.
 		 */
-		g_object_unref( object );
+		g_object_unref( new_object );
 	}
 	else if( G_IS_PARAM_SPEC_BOOLEAN( pspec ) ) {
 		gboolean b;
@@ -1375,7 +1417,30 @@ vips_object_get_argument_to_string( VipsObject *object,
 
 	g_assert( argument_class->flags & VIPS_ARGUMENT_OUTPUT );
 
-	if( g_type_is_a( otype, VIPS_TYPE_OBJECT ) &&
+	if( g_type_is_a( otype, VIPS_TYPE_IMAGE ) &&
+		(oclass = g_type_class_ref( VIPS_TYPE_FILE_SAVE )) ) {
+		VipsObject *new_object;
+		VipsImage *in;
+
+		/* Use VipsFile to make a saver, set 'in' on that and run
+		 * build to make it write.
+		 */
+		if( !(new_object = 
+			vips_object_new_from_string( oclass, arg )) )
+			return( -1 );
+
+		g_object_get( object, name, &in, NULL );
+		g_object_set( new_object, "in", in, NULL );
+		g_object_unref( in );
+
+		if( vips_object_build( new_object ) ) {
+			g_object_unref( new_object );
+			return( -1 );
+		}
+
+		g_object_unref( new_object );
+	}
+	else if( g_type_is_a( otype, VIPS_TYPE_OBJECT ) &&
 		(oclass = g_type_class_ref( otype )) &&
 		oclass->output_to_arg ) {
 		VipsObject *value;
@@ -1538,11 +1603,6 @@ vips_object_new_from_string( VipsObjectClass *object_class, const char *p )
 		}
 	}
 
-	if( vips_object_build( object ) ) {
-		g_object_unref( object );
-		return( NULL );
-	}
-
 	return( object ); 
 }
 
diff --git a/libvips/iofuncs/vips.c b/libvips/iofuncs/vips.c
index 1603ccc4..a86df9af 100644
--- a/libvips/iofuncs/vips.c
+++ b/libvips/iofuncs/vips.c
@@ -218,6 +218,19 @@ vips__write_2byte( unsigned char **to, unsigned char *from )
 	*to += 2;
 }
 
+guint32
+vips__file_magic( const char *filename )
+{
+	guint32 magic;
+
+	if( vips__get_bytes( filename, (unsigned char *) &magic, 4 ) &&
+		(magic == VIPS_MAGIC_INTEL || 
+		 magic == VIPS_MAGIC_SPARC ) )
+		return( magic );
+
+	return( 0 );
+}
+
 /* offset, read, write functions.
  */
 typedef struct _FieldIO {