/* create an in-memory/image-surface and generate a cairo-context from that */
cairo_t*
create_cairo_context (int               width,   /* 16 in your case         */
		      int               height,  /* 16 in your case         */
		      int               channels,/* only 3 or 4 makes sense */
		      cairo_surface_t** surface, /* pass valid pointer      */
		      unsigned char**   buffer)  /* pass valid pointer      */
{
	cairo_t* context = NULL;

	*buffer = calloc (channels * width * height, sizeof (unsigned char));
	if (!*buffer)
	{
		printf ("create_cairo_context() - Couldn't allocate buffer\n");
		return NULL;
	}

	*surface = cairo_image_surface_create_for_data (*buffer,
							CAIRO_FORMAT_ARGB32,
							width,
							height,
							channels * width);
	if (cairo_surface_status (*surface) != CAIRO_STATUS_SUCCESS)
	{
		free (*buffer);
		printf ("create_cairo_context() - Couldn't create surface\n");
		return NULL;
	}

	context = cairo_create (*surface);
	if (cairo_status (context) != CAIRO_STATUS_SUCCESS)
	{
		free (*buffer);
		printf ("create_cairo_context() - Couldn't create context\n");
		return NULL;
	}

	return context;
}

GdkPixbuf* get_pixbuf_from_context (guchar* buffer,
				    gint    channels,
				    gint    width,
				    gint    height)
{
	GdkPixbuf* pixbuf = NULL;

	pixbuf = gdk_pixbuf_new_from_data (buffer,
					   GDK_COLORSPACE_RGB,
					   channels == 4? TRUE : FALSE,
					   8, /* usually save to assume :) */
					   width,
					   height,
					   channels * width,
                                           NULL,
					   NULL);

	return pixbuf;
}

cairo_t*         context = NULL;
cairo_surface_t* surface = NULL;
guchar*          buffer  = NULL;
GdkPixbuf*       pixbuf  = NULL;

context = create_cairo_context (16, 16, 3, &surface, &buffer);
/* do your drawing here with cairo */
pixbuf = get_pixbuf_from_buffer (buffer, 3, 16, 16);
cairo_destroy (context);