/usr/include/vxl/contrib/conversions/math/ is in libvxl1-dev 1.17.0.dfsg2-4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/vxl/contrib/conversions/math/CoolMatrix_to_vnl_matrix.h
/usr/include/vxl/contrib/conversions/math/CoolVector_to_vnl_vector.h
/usr/include/vxl/contrib/conversions/math/IUE_matrix_to_vnl_matrix.h
/usr/include/vxl/contrib/conversions/math/IUE_vector_to_vnl_vector.h
/usr/include/vxl/contrib/conversions/math/vbl_array_to_vnl_matrix.h
/usr/include/vxl/contrib/conversions/math/vbl_array_to_vnl_vector.h
/usr/include/vxl/contrib/conversions/math/vnl_matrix_to_CoolMatrix.h
/usr/include/vxl/contrib/conversions/math/vnl_matrix_to_IUE_matrix.h
/usr/include/vxl/contrib/conversions/math/vnl_matrix_to_vbl_array.h
/usr/include/vxl/contrib/conversions/math/vnl_vector_to_CoolVector.h
/usr/include/vxl/contrib/conversions/math/vnl_vector_to_IUE_vector.h
/usr/include/vxl/contrib/conversions/math/vnl_vector_to_vbl_array.h