add hough_circle() to vipsCC and python

now exposed to Python and C++

ChangeLog

@@ -31,6 +31,7 @@
 - support 1/2/4 bit palette tiff images with alpha
 - vips_system() now uses g_spawn_command_line_sync()
 - added im_tile_cache_random() to help nip2
+- added hough_circle() to vips7 C++ API
 
 6/3/14 started 7.38.6
 - grey ramp minimum was wrong

TODO

@@ -1,3 +1,4 @@
+- fix vipsthumbnail Chicago.png, again
 
 - can we use postbuild elsewhere? look at use of "preclose" / "written", etc. 
 

libvipsCC/VImage.cc

@@ -329,6 +329,29 @@ int VImage::Yoffset() { return( _ref->im->Yoffset ); }
 const char *VImage::filename() { return( _ref->im->filename ); }
 const char *VImage::Hist() { return( im_history_get( _ref->im ) ); }
 
+VImage VImage::hough_circle( int scale, int min_radius, int max_radius ) 
+	throw( VError )
+{
+	VImage in = *this;
+	VipsImage *x;
+	VImage out;
+
+	if( vips_hough_circle( in.image(), &x,
+		"scale", scale,
+		"min_radius", min_radius,
+		"max_radius", max_radius,
+		NULL ) )
+		verror();
+
+	if( vips_image_write( x, out.image() ) ) {
+		g_object_unref( x );
+		verror();
+	}
+	g_object_unref( x );
+
+	return( out );
+}
+
 // metadata
 
 // base functionality

libvipsCC/include/vips/VImage.h

@@ -256,6 +256,9 @@ public:
 	const char *filename();
 	const char *Hist();
 
+	// need the hough circle stuff for the rode python GUI
+	VImage hough_circle( int scale, int min_radius, int max_radius ) throw( VError );
+
 	// metadata
 #ifndef SWIG
 	// base functionality