BOOST_REQUIRE_EQUAL (ref_image->data(0)[off], image->data(0)[off]);
BOOST_REQUIRE_EQUAL (ref_image->data(1)[off], image->data(1)[off]);
BOOST_REQUIRE_EQUAL (ref_image->data(2)[off], image->data(2)[off]);
BOOST_REQUIRE_EQUAL (ref_image->data(0)[off], image->data(0)[off]);
BOOST_REQUIRE_EQUAL (ref_image->data(1)[off], image->data(1)[off]);
BOOST_REQUIRE_EQUAL (ref_image->data(2)[off], image->data(2)[off]);