[C++-sig] help passing image data

[J.D. Yamokoski]

Alright, I thank everyone for their suggestions so far. Following 
earlier advice, I am trying a little easier embedding project - just 
trying to make a simple (not CImg) object available in a python 
environment. The problem is that the program crashes when started. First 
here is the code I have so far - much has been copied from various 
things I have found on the web (I can include a zip of the VS workspace 
if anyone is really interested):

First the ultra basic class I am trying to share with python:

-- Begin Values.h
class Values
{
public:
	Values(void);
	~Values(void);

	float GetA();
	float GetB();

	void SetA(float A);
	void SetB(float B);

protected:
	float a;
	float b;
};
-- End Values.h


Then my wrapping of this class using boost,

-- Begin ValuesModule.h

#include <boost/python.hpp>
using namespace boost::python;

#include "Values.h"

object value_class = class_< Values >("Values")
		.def( "get_a", &Values::GetA )
		.def( "get_b", &Values::GetB )
		.def( "set_a", &Values::SetA )
		.def( "set_b", &Values::SetB );

extern object value_obj = value_class();

BOOST_PYTHON_MODULE(Values)
{
	value_class;
}

-- End ValuesModule.h

To keep this simple I won't get into the rest of the code, partly 
because the program is crashing when it creates the global value_obj. 
The call stack pointer stops at the creation of this object and I get an 
"Access violation reading..." some memory address.

My thoughts so far were to create this global value_obj. Later right 
before a call to PyRun_String, I add this object to the global 
dictionary by,

object main_module ((
	handle<>( borrowed( PyImport_AddModule("__main__") ) )
));

object main_namespace = main_module.attr("__dict__");

// Insert the app's global value_obj into the python dictionary
if ( PyDict_SetItem( main_namespace.ptr()
		 , PyString_FromString("valueobj")
		 , value_obj.ptr() ) == -1 )
{
throw python_exception( "Could not add value_obj to the dictionary!" );
}

But I am stuck simply creating the object for right now. Any suggestions?