support :level,associated in the vips7 openslide

the vips7 stub for openslide now supports :level,associated mode
options, eg:

$ header CMU-2.svs
CMU-2.svs: 19500x7615 uchar, 4 bands, rgb VipsImage (0x236a060)
$ header CMU-2.svs:2
CMU-2.svs:2: 4875x1903 uchar, 4 bands, rgb VipsImage (0x244c060)
$ header CMU-2.svs:,label
CMU-2.svs:,label: 387x463 uchar, 4 bands, rgb VipsImage (0xa2d060)
$ header CMU-2.svs:2,label
CMU-2.svs:2,label: 387x463 uchar, 4 bands, rgb VipsImage (0x1b23060)

ChangeLog

@@ -4,6 +4,7 @@
 - fix openslide read: always return png-style rgba, im_argb2rgba() becomes a
   NOP
 - cast to unsigned int now removes <0 values
+- vips7 interface to openslide now supports :,level,associated options
 
 13/3/12 started 7.28.2
 - xres/yres tiffsave args were broken

libvips/deprecated/im_openslide2vips.c

@@ -2,6 +2,8 @@
  *
  * 17/12/11
  * 	- just a stub
+ * 11/4/12
+ * 	- support :level,associated in filenames
  */
 
 /*
@@ -49,11 +51,28 @@
 #include <vips/internal.h>
 
 static int
-im_openslide2vips( const char *filename, IMAGE *out )
+im_openslide2vips( const char *name, IMAGE *out )
 {
+	char filename[FILENAME_MAX];
+	char mode[FILENAME_MAX];
+	char *p, *q;
+	char *associated;
+	int level;
 	VipsImage *t;
 
-	if( vips_openslideload( filename, &t, NULL ) )
+	im_filename_split( name, filename, mode );
+	level = 1;
+	associated = NULL;
+	p = &mode[0];
+	if( (q = im_getnextoption( &p )) ) 
+		level = atoi( q );
+	if( (q = im_getnextoption( &p )) ) 
+		associated = q;
+
+	if( vips_openslideload( filename, &t, 
+		"level", level,
+		"associated", associated,
+		NULL ) )
 		return( -1 );
 	if( vips_image_write( t, out ) ) {
 		g_object_unref( t );

python/try4.py

@@ -0,0 +1,12 @@
+#!/usr/bin/python
+
+import sys
+from vips8 import vips
+from gi.repository import Vips
+
+a = vips.Image(sys.argv[1])
+b = vips.Image(sys.argv[2])
+
+c = a.join(b, Vips.Direction.HORIZONTAL, expand = True)
+
+c.write_to_file(sys.argv[3])